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Published Medical Research

07/30/2018 - Retrieval of a periodontally compromised tooth by allogeneic grafting of mesenchymal stem cells from dental pulp: A case report
Abstract
To report a case of successful allogeneic grafting of mesenchymal dental pulp stem cells (DPSCs) as preliminary findings in a patient with periodontal disease enrolled into clinical trial ISRCTN12831118.
Mesenchymal stem cells from the dental pulp of a deciduous tooth from a 7-year-old donor were separated from the pulp chamber and processed via enzymatic digestion and centrifugation. DPSCs were passaged and cultured on a 35?×?13 mm culture dish in minimum essential medium-alpha, without supplementation. After reaching 80% confluency, 5 x 106allogeneic DPSCs in 250 µl phosphate buffered saline were seeded onto a dry scaffold of lyophilized collagen-polyvinylpyrrolidone sponge placed in the left lower premolar area of a 61-year-old patient with periodontal disease. Surgical access to the lower premolar area was achieved using the flap technique.
At 3 and 6 months following allogeneic graft, the patient showed no sign of rejection and exhibited decreases in tooth mobility, periodontal pocket depth and bone defect area. Bone mineral density had increased at the graft site.
Regenerative periodontal therapy using DPSCs of allogeneic origin may be a promising treatment for periodontal disease-induced bone defects.
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07/30/2018 - Three-Dimensional Bioprinting Nanotechnologies towards Clinical Application of Stem Cells and Their Secretome in Salivary Gland Regeneration

Abstract

Salivary gland (SG) functional damage and severe dry mouth (or xerostomia) are commonly observed in a wide range of medical conditions from autoimmune to metabolic disorders as well as after radiotherapy to treat specific head and neck cancers. No effective therapy has been developed to completely restore the SG functional damage on the long-term and reverse the poor quality of life of xerostomia patients. Cell- and secretome-based strategies are currently being tested in vitro and in vivo for the repair and/or regeneration of the damaged SG using (1) epithelial SG stem/progenitor cells from salispheres or explant cultures as well as (2) nonepithelial stem cell types and/or their bioactive secretome. These strategies will be the focus of our review. Herein, innovative 3D bioprinting nanotechnologies for the generation of organotypic cultures and SG organoids/mini-glands will also be discussed. These bioprinting technologies will allow researchers to analyze the secretome components and extracellular matrix production, as well as their biofunctional effects in 3D mini-glands ex vivo. Improving our understanding of the SG secretome is critical to develop effective secretome-based therapies towards the regeneration and/or repair of all SG compartments for proper restoration of saliva secretion and flow into the oral cavity.

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07/30/2018 - Gingival mesenchymal stem cells

Abstract

The human gingiva, characterized by its outstanding scarless wound healing properties, is a unique tissue and a pivotal component of the periodontal apparatus, investing and surrounding the teeth in their sockets in the alveolar bone. In the last year's gingival mesenchymal stem/progenitor cells (GMSCs), with promising regenerative and immunomodulatory properties, have been isolated and characterized from the gingival lamina propria. These cells, in contrast to other mesenchymal stem/progenitor cell (MSC) sources, are abundant, readily accessible and easily obtainable through minimally invasive cell isolation techniques. This short communication summarizes the current scientific evidence on GMSCs.

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07/27/2018 - Cell sheet-engineered bones used for the reconstruction of mandibular defects in an animal model

Abstract

The aim of the present study was to investigate the generation of cell sheet-engineered bones used for the reconstruction of mandibulardefects. Bone marrow stem cells (BMSCs) were cultured and induced to generate osteoblasts. Poly(lactic-co-glycolic acid) (PLGA) scaffolds were wrapped with or without cell sheets and then implanted into dogs with mandibular defects in the right side (experimental group) or the left side (control group), respectively. Subsequently, X-ray analyses, and hematoxylin and eosin staining were performed at various time points (at 4, 8, 12 or 16 weeks post-implantation; n=4 at each time point). The osteogenesis in the experimental group was significantly improved compared with that in the control group. At 16 weeks after implantation, numerous Haversian systems and a few lamellar bones were observed at the periphery. In the control group, the engineered bone (without BMSC sheets) presented fewer Haversian systems and no lamellar bones. The optical density of the fresh bone in the experimental group was significantly higher compared with that in the control group (P<0.05). In conclusion, tissue-engineered bone with the structure of lamellar bones can be generated using BMSC sheets and implantation of these bones had an improved effects compared with the control group. Cell sheet transplantation was found to enhance bone formation at the reconstruction site of the mandibular defects.

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07/27/2018 - Cell-Based Therapies for the Treatment of Hearing Loss

Abstract

Hearing loss in mammals is an irreversible process caused by degeneration of the hair cells of the inner ear. Current therapies for hearing loss include hearing aids and cochlear implants that provide substantial benefits to most patients, but also have several shortcomings. There is great interest in the development of regenerative therapies to treat deafness in the future. Cell-based therapies, based either on adult, multipotent stem, or other types of pluripotent cells, offer promise for generating differentiated cell types to replace lost or damaged hair cellsof the inner ear. In this review, we focus on the methods proposed and avenues for research that seem the most promising for stem cell-based auditory sensory cell regeneration, from work collected over the past 15 years.

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07/27/2018 - Salivary glands regenerate after radiation injury through SOX2-mediated secretory cell replacement

Abstract

Salivary gland acinar cells are routinely destroyed during radiation treatment for head and neck cancer that results in a lifetime of hyposalivation and co-morbidities. A potential regenerative strategy for replacing injured tissue is the reactivation of endogenous stem cellsby targeted therapeutics. However, the identity of these cells, whether they are capable of regenerating the tissue, and the mechanisms by which they are regulated are unknown. Using in vivo and ex vivo models, in combination with genetic lineage tracing and human tissue, we discover a SOX2+ stem cell population essential to acinar cell maintenance that is capable of replenishing acini after radiation. Furthermore, we show that acinar cell replacement is nerve dependent and that addition of a muscarinic mimetic is sufficient to drive regeneration. Moreover, we show that SOX2 is diminished in irradiated human salivary gland, along with parasympathetic nerves, suggesting that tissue degeneration is due to loss of progenitors and their regulators. Thus, we establish a new paradigm that salivary glands can regenerate after genotoxic shock and do so through a SOX2 nerve-dependent mechanism.

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07/26/2018 - Reconstruction of Drug-induced Cleft Palate Using Bone Marrow Mesenchymal Stem Cell in Rodents

Abstract

Triamcinolone acetonide (TAC) (Kenacort*) is a commonly used synthetic glucocorticoid in today's medical practice. The drug is also a potential agent in inducing cleft palates in rats. This drug has been used to induce cleft palate in the fetus of the pregnant rats to bring out a suitable animal model for human cleft lip and palate. The drug was given intraperitoneally to induce congenital cleft palate in pregnant mother rats.

The aim of this study is to induce congenital cleft palate in pregnant Wister albino rats and reconstruct the defect with bone marrow mesenchymal stem cells (BMSCs) isolated from the same species along with PLGA (poly lactic co glycolic acid) scaffold.

Twenty female animals were divided into two groups. Each group contains 10 animals. The animals were allowed to mate with male rat during the esterase period and the day, in hich vaginal plug was noticed was taken to be day 0. The pregnant rats were given triamcinolone acetonide (Kenacort* 10 mg/1 ml intramuscularly/intravenous [IM/IV] injections) injection intraperitoneally at two different dosages as the existing literature. The injection was given on the 10, 12, and 14th day of gestation. The clinical changes observed were recorded, and the change in the body weight was noted carefully. Group 1 which received 0.5 mg/kg body weight of TAC had many drug toxic effects. Group 2 which received 0.05 mg/kg body weight produced cleft palate in rat pups. The pups were divided into three groups. Group A control group without cell transplant, the cleft was allowed to close by itself. Group B containing palate reconstructed with plain PLGA scaffold (Bioscaffold, Singapore) without BMSC, Group C containing BMSC and PLGA scaffold (Bioscaffold, Singapore), Group C operated for the cleft palate reconstruction using BMSCs and PLGA scaffold. There was faster and efficient reconstruction of bone in the cleft defect in Group C while there was no defect closure in Group A and B.

There was complete reconstruction of the cleft palate in the group of rat pups which received BMSCs along with PLGA scaffold. Bone growth in the cleft defect was faster; complete fusion of the defect was achieved.

The dosage of drug used for inducing cleft palate was standardized in rodents for a definitive congenital cleft palate model. The cleft palate induced was reconstructed using BMSCs and PLGA scaffold. This was compared with a control group and the other group with plain PLGA used for reconstruction of the palate. This study will invite future research in the effect of the drug on human beings, especially on pregnant mothers.

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07/26/2018 - Stem cells: a promising candidate to treat neurological disorders.

Abstract

Neurologic impairments are usually irreversible as a result of limited regeneration in the central nervous system. Therefore, based on the regenerative capacity of stem cells, transplantation therapies of various stem cells have been tested in basic research and preclinical trials, and some have shown great prospects. These cells have all been considered as candidates to treat several major neurological disorders and diseases, owing to their self-renewal capacity, multi-directional differentiation, neurotrophic properties, and immune modulation effects. We also review representative basic research and recent clinical trials using stem cells for neurodegenerative diseases, including Parkinson's disease, Alzheimer's disease, and age-related macular degeneration, as well as traumatic brain injury and glioblastoma. In spite of a few unsuccessful cases, risks of tumorigenicity, and ethical concerns, most results of animal experiments and clinical trials demonstrate efficacious therapeutic effects of stem cells in the treatment of nervous system disease. In summary, these emerging findings in regenerativemedicine are likely to contribute to breakthroughs in the treatment of neurological disorders. Thus, stem cells are a promising candidate for the treatment of nervous system diseases.

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07/26/2018 - Characterization of Primary Epithelial Cells Derived from Human Salivary Gland Contributing to in vivo Formation of Acini-like Structures

Abstract

Patients with head and neck cancer are treated with therapeutic irradiation, which can result in irreversible salivary gland dysfunction. Because there is no complete cure for such patients, stem cell therapy is an emerging alternative for functional restoration of salivary glands. In this study, we investigated in vitrocharacteristics of primarily isolated epithelial cells from human salivary gland (Epi-SGs) and in vivo formation of acini-like structures by Epi-SGs. Primarily isolated Epi-SGs showed typical epithelial cell-like morphology and expressed E-cadherin but not N-cadherin. Epi-SGs expressed epithelial stem cell (EpiSC) and embryonic stem cell (ESC) markers. During long-term culture, the expression of EpiSC and ESC markers was highly detected and maintained within the core population with small size and low cytoplasmic complexity. The core population expressed cytokeratin 7 and cytokeratin 14, known as duct markers indicating that Epi-SGs might be originated from the duct. When Epi-SGs were transplanted in vivo with Matrigel, acini-like structures were readily formed at 4 days after transplantation and they were maintained at 7 days after transplantation. Taken together, our data suggested that Epi-SGs might contain stem cells which were positive for EpiSC and ESC markers, and Epi-SGs might contribute to the regeneration of acini-like structures in vivo. We expect that Epi-SGs will be useful source for the functional restoration of damaged salivary gland.

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07/25/2018 - Cell sheet composed of adipose-derived stem cells demonstrates enhanced skin wound healing with reduced scar formation
Abstract
Adipose-derived stem cell (ASC) sheets exhibit great potential for tissue regeneration. In this study, we investigated whether ASC sheets can ameliorate skin wound healing with reduced scar formation, and faster wound healing was observed when applying ASC sheets in an impaired wound healing model of mice. The neoskin formed in the presence of ASC sheets exhibited a thickness comparable to normal skin with a more organized collagen structure. In vitro experiments suggested that the anti-scarring effect of the ASC sheets was partly mediated through increased secretion of hepatocyte growth factor. Moreover, ASC sheets secreted significantly more C1q/TNF-related protein-3, which may account for the decreased recruitment of macrophages into the wound tissue. Therefore, ASC sheets possess the necessary paracrine factors to improve skin wound healing with less scarring, thus representing a desirable method of topical wound treatment.
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07/25/2018 - Reconstruction of mandibular defects with autogenous bone and decellularized bovine bone grafts with freeze-dried bone marrow stem cell paracrine factors

Abstract

The gold standard following segmental mandibulectomy is vascularized autologous bone graft in the form of the fibula flap. However, in bone reconstruction the use of autogenous bone does not always guarantee a successful outcome. The aim of the present investigation was to develop a novel biologically active bone (BAB) graft, and to use it for the reconstruction of large size defects of the mandible bone following tumor resection. In the first part of the present study, biologically active bone graft was developed by using human freeze-dried bone marrow stem cells (BMSCs) paracrine factors and three-dimensional bone scaffold derived from cancellous bovine bone following decellularization. In the second part of the research, one male and three female patients with primary tumors of the mandible underwent hemimandibulectomy. The mandibular bone defects following tumor resection were reconstructed with autogenous rib grafts in three patients and BAB graft was used in one patient. The graft-host interfaces were covered with decellularized human amnion/chorion membrane graft. All patients were followed-up every five months following the reconstruction of the mandible, with no complications observed. Preliminary clinical investigations demonstrated that a BAB graft containing freeze-dried BMSC paracrine factors may be used for the reconstruction of large mandibular bone defects following tumor resection.

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07/25/2018 - A glance at methods for cleft palate repair

Abstract

Cleft palate is the second most common birth defect and is considered as a challenge for pediatric plastic surgeons. There is still a general lack of a standard protocol and patients often require multiple surgical interventions during their lifetime along with disappointing results.

PubMed search was undertaken using search terms including 'cleft palate repair', 'palatal cleft closure', 'cleft palate + stem cells', 'cleft palate + plasma rich platelet', 'cleft palate + scaffold', 'palatal tissue engineering', and 'bone tissue engineering'. The found articles were included if they defined a therapeutic strategy and/or assessed a new technique.

We reported a summary of the key-points concerning cleft palate development, the genes involving this defect, current therapeutic strategies, recently novel aspects, and future advances in treatments for easy and fast understanding of the concepts, rather than a systematic review. In addition, the results were integrated with our recent experience.

Tissue engineering may open a new window in cleft palate reconstructionStem cells and growth factors play key roles in this field.

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07/24/2018 - Juvenile Swine Surgical Alveolar Cleft Model to Test Novel Autologous Stem Cell Therapies

Abstract

Reconstruction of craniofacial congenital bone defects has historically relied on autologous bone grafts. Engineered bone using mesenchymal stem cells from the umbilical cord on electrospun nanomicrofiber scaffolds offers an alternative to current treatments. This preclinical study presents the development of a juvenile swine model with a surgically created maxillary cleft defect for future testing of tissue-engineered implants for bone generation. Five-week-old pigs (n=6) underwent surgically created maxillary (alveolar) defects to determine critical-sized defect and the quality of treatment outcomes with rib, iliac crest cancellous bone, and tissue-engineered scaffolds. Pigs were sacrificed at 1 month. Computed tomography scans were obtained at days 0 and 30, at the time of euthanasia. Histological evaluation was performed on newly formed bone within the surgical defect. A 1?cm surgically created defect healed with no treatment, the 2?cm defect did not heal. A subsequently created 1.7?cm defect, physiologically similar to a congenitally occurring alveolar cleft in humans, from the central incisor to the canine, similarly did not heal. Rib graft treatment did not incorporate into adjacent normal bone; cancellous bone and the tissue-engineered graft healed the critical-sized defect. This work establishes a juvenile swine alveolar cleft model with critical-sized defect approaching 1.7?cm. Both cancellous bone and tissue engineered graft generated bridging bone formation in the surgically created alveolar cleft defect.
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07/24/2018 - Three-dimensionally printed polyetherketoneketone scaffolds with mesenchymal stem cells for the reconstruction of critical-sized mandibular defects

Abstract

Additive manufacturing offers a tailored approach to tissue engineering by providing anatomically precise scaffolds onto which stem cells and growth factors can be supplied. Polyetherketoneketone (PEKK), an ideal candidate biomaterial, is limited by a poor implant-bone interface but can be functionalized with adipose-derived stem cells (ADSC) to promote integration. This in vivo study examined the interaction of a three-dimensional printed PEKK/ADSC implant within the critical-sized mandibular defect in a rabbit model.

All scaffolds were well integrated into adjacent bone. Bone-to-tissue volume increased from 30.34% (?±?12.46) to 61.27% (?±?8.24), and trabecular thickness increased from 0.178?mm (?±?0.069) to 0.331?mm (?±?0.0306) in the 10- and 20-week groups, respectively, compared to no bone regrowth on the control side (P?<?0.05). Histology confirmed integration at the bone-implant interface. Biomechanical testing revealed a compressive resistance 15 times that of bone alone (P?<?0.05) CONCLUSION: 3D-printed PEKK scaffolds combined with ADSCs present a promising solution to improve the bone-implant interface and increase the resistance to forces of mastication after mandibular reconstruction.

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07/24/2018 - Transplantation of adipose tissue-derived stem cells into brain through cerebrospinal fluid in rat models: Protocol development and initial outcome data.

Abstract

Cell therapy is an important strategy for the treatment of incurable diseases including those that occur in the central nervous system (CNS). Among different strategies, the method of delivering or transplantation of cells into the brain has shown significant effects on regeneration. In this study, a new protocol has been developed for the transplantation of adipose tissue-derived stem cells into the brain through cerebrospinal fluid (CSF) in rat models. The findings showed the presence of transplanted human adipose-derived stem cells (hADSC) in the cerebellum and basal ganglia following three days and also after two months that confirmed the entrance of transplanted cells into the cerebrospinal fluid and migration of them into the brain tissue. All the animals survived after the transplantation process, with the lowest side effects compared to the available conventional methods. It can be concluded that the cells could be efficiently transplanted into CSF through subarachnoid space by injection via superior orbital fissure with a minimally invasive technique.

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07/23/2018 - An Investigation on the Regenerative Effects of Intra Articular Injection of Co-Cultured Adipose Derived Stem Cells with Chondron for Treatment of Induced Osteoarthritis

Abstract

Adipose tissue derived stem cells (ASCs) and chondrocytes are best cells for articular cartilage regeneration. Chondrocyte with peri-cellular matrix (PCM) is called chondron provides ideal microenviroment than chondrocytes. We aimed to evaluate the regenerative effects of intra-articular injection of ASCs co-cultures with chondron in induced osteoarthritis (OA). 

ASC, from the peri-renal fat of male rat and chondron from primary newborn rat hyaline cartilage were isolated. ASCs were cultured for at least three passages in vitro. Six weeks after OA induction, rats were randomly distributed in five groups of control, osteoarthritic, ASC, chondron and co-cultured. ASCs (107), chondrons (107) and combination of chondrons and ASCs (107) were injected into intra-articular space of the rat knee. The effect of treatments was evaluated by macroscopic and microscopic examinations. The expression levels of collagen type ?? was studied by immunohistochemistry. 

Co-culture of chondrons and ASCs increased articular hyaline cartilage formation and provides a useful tool to improve limitations of each of applied cells in this model.

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07/23/2018 - The establishment of a chemically defined serum-free culture system for human dental pulp stem cells

Abstract

The concept of establishing a dental stem cell (DSC) bank for oral and maxillofacial regeneration has become of great interest. The routine application of serum-containing conditions for human DSC (hDSC) culture is in great controversy considering that the animal-originated serum can cause serious ethical concerns and lead to increasingly irrelevant variables, errors, and poor repeatability of experiment results. Thus, this study aimed to establish a safe, stable and efficient hDSC serum-free culturing system for future DSC bank usage.

Dental pulp stem cells (DPSCs) from human permanent tooth pulp were isolated, expanded, passaged, and divided into two groups according to their culture conditions: group 1 was the serum-containing medium (SCM) group; and group 2 was the serum-free Essential 8 medium (E8) group. DPSCs were characterized first, followed by cell proliferation, pluripotency, and migration study in SCM and E8 medium.

Human DPSCs (hDPSCs) in E8 medium demonstrated greater proliferation, pluripotency, migration ability and less apoptosis. hDPSCs could be successfully induced to the adipogenic, osteogenic, neurogenic, and chondrogenic lineages in E8 group. Real-time polymerase chain reaction indicated that the expression of PPAR-?, RUNX2, OCN and MAP-2 was higher in E8 group.  CONCLUSIONS: Compared with serum-containing medium, E8 medium exhitibed higher ability in maintaining the cell proliferation, pluripotency, migration, and stability. This new serum-free culture environment might be applicable for hDSC culture in the future.

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07/23/2018 - The effect of platelet-rich plasma on human mesenchymal stem cell-induced bone regeneration of canine alveolar defects with calcium phosphate-based scaffolds

Abstract

Autologous bone transplantation known as the "gold standard" to reconstruction of osseous defects has known disadvantages. This study was designed to explore the effects of hydroxy-apatite/tricalcium-phosphate (HA/TCP) and platelet-rich plasma (PRP) on the osteogenesis ability of human adipose-derived mesenchymal stem cells (hAdMSCs) in vitro and in vivo.

Based on this study, application of stem cells could offer a helpful therapeutic tool in bone tissue regeneration. Although inserted hAdMSCs were identifiable throughout the newly-formed bone tissue, their few number could be an indicator of indirect role of hAdMSCs in tissue regeneration.

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07/23/2018 - Comparison of the bone regeneration ability between stem cells from human exfoliated deciduous teeth, human dental pulp stem cells and human bone marrow mesenchymal stem cells

Abstract

Cleft lip and palate is the most common congenital anomaly in the orofacial region. Autogenous iliac bone graft, in general, has been employed for closing the bone defect at the alveolar cleft. However, such iliac bone graft provides patients with substantial surgical and psychological invasions. Consequently, development of a less invasive method has been highly anticipated. Stem cells from human exfoliated deciduous teeth (SHED) are a major candidate for playing a significant role in tissue engineering and regenerative medicine. The aim of this study was to elucidate the nature of bone regeneration by SHED as compared to that of human dental pulp stem cells (hDPSCs) and bone marrow mesenchymal stem cells (hBMSCs).

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05/12/2017 - Three-Dimensional Printed Scaffolds with Multipotent Mesenchymal Stromal Cells for Rabbit Mandibular Reconstruction and Engineering

Abstract

Multipotent mesenchymal stromal cells (MSC) derived from both the bone marrow and adipose tissue possess the ability to differentiate into multiple cell lineages, regulate the immune function by secreting numerous bioactive paracrine factors, and hold great potential in cell therapy and tissue engineering. When combined with three-dimensional (3D) scaffolds, MSC can be used for bone defect reconstruction and engineering. This protocol describes the isolation of bone marrow mesenchymal stromal cells (BMMSC) and adipose-tissue derived stem cells (ADSC) from rabbits for subsequent seeding on tissue-engineered 3D-printed scaffolds and transplantation into a rabbit-model with the goal of repairing large osseous mandibular defects (one quarter of the lower jaw is removed surgically). Steps to demonstrate the three cell differentiation lineage potentials of BMMSC and ADSC into osteocytes, adipocytes, and chondrocytes are described. A modified cell seeding method using syringes on scaffold is detailed. Creating a large mandibular bone defect, the rapid prototyping method to print a customized 3D-scaffold, the scaffold implantation procedure in rabbits, and microcomputed tomography (micro-CT) analysis are also described. 

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05/12/2017 - Concise Review: Salivary Gland Regeneration: Therapeutic Approaches from Stem Cells to Tissue Organoids.

Abstract

The human salivary gland (SG) has an elegant architecture of epithelial acini, connecting ductal branching structures, vascular and neuronal networks that together function to produce and secrete saliva. This review focuses on the translation of cell- and tissue-based research toward therapies for patients suffering from SG hypofunction and related dry mouth syndrome (xerostomia), as a consequence of radiation therapy or systemic disease. We will broadly review the recent literature and discuss the clinical prospects of stem/progenitor cell and tissue-based therapies for SG repair and/or regeneration. Thus far, several strategies have been proposed for the purpose of restoring SG function: (1) transplanting autologous SG-derived epithelial stem/progenitor cells; (2) exploiting non-epithelial cells and/or their bioactive lysates; and (3) tissue engineering approaches using 3D (three-dimensional) biomaterials loaded with SG cells and/or bioactive cues to mimic in vivo SGs. We predict that further scientific improvement in each of these areas will translate to effective therapies toward the repair of damaged glands and the development of miniature SG organoids for the fundamental restoration of saliva secretion. 


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05/02/2017 - Neural Stem Cell-Based Regenerative Approaches for the Treatment of Multiple Sclerosis.

Abstract


Multiple sclerosis (MS) is a chronic, autoimmune, inflammatory, and demyelinating disorder of the central nervous system (CNS), which ultimately leads to axonal loss and permanent neurological disability. Current treatments for MS are largely comprised of medications that are either immunomodulatory or immunosuppressive and are aimed at reducing the frequency and intensity of relapses. Neural stem cells (NSCs) in the adult brain can differentiate into oligodendrocytes in a context-specific manner and are shown to be involved in the remyelination in these patients. NSCs may exert their beneficial effects not only through oligodendrocyte replacement but also by providing trophic support and immunomodulation, a phenomenon now known as "therapeutic plasticity." In this review, we first provided an update on the current knowledge regarding MS pathogenesis and the role of immune cells, microglia, and oligodendrocytes in MS disease progression. Next, we reviewed the current progress on research aimed toward stimulating endogenous NSC proliferation and differentiation to oligodendrocytes in vivo and in animal models of demyelination. In addition, we explored the neuroprotective and immunomodulatory effects of transplanted exogenous NSCs on T cell activation, microglial activation, and endogenous remyelination and their effects on the pathological process and prognosis in animal models of MS. Finally, we examined various protocols to generate genetically engineered NSCs as a potential therapy for MS. Overall, this review highlights the studies involving the immunomodulatory, neurotrophic, and regenerative effects of NSCs and novel methods aiming at stimulating the potential of NSCs for the treatment of MS.


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04/18/2017 - Adult muscle-derived stem cells engraft and differentiate into insulin-expressing cells in pancreatic islets of diabetic mice

Abstract


BACKGROUND:

Pancreatic beta cells are unique effectors in the control of glucose homeostasis and their deficiency results in impaired insulin production leading to severe diabetic diseases. Here, we investigated the potential of a population of nonadherent muscle-derived stem cells (MDSC) from adult mouse muscle to differentiate in vitro into beta cells when transplanted as undifferentiated stem cells in vivo to compensate for beta-cell deficiency.

RESULTS:

In vitro, cultured MDSC spontaneously differentiated into insulin-expressing islet-like cell clusters as revealed using MDSC from transgenic mice expressing GFP or mCherry under the control of an insulin promoter. Differentiated clusters of beta-like cells co-expressed insulin with the transcription factors Pdx1, Nkx2.2, Nkx6.1, and MafA, and secreted significant levels of insulin in response to glucose challenges. In vivo, undifferentiated MDSC injected into streptozotocin (STZ)-treated mice engrafted within 48 h specifically to damaged pancreatic islets and were shown to differentiate and express insulin 10-12 days after injection. In addition, injection of MDSC into hyperglycemic diabetic mice reduced their blood glucose levels for 2-4 weeks.

CONCLUSION:

These data show that MDSC are capable of differentiating into mature pancreatic beta islet-like cells, not only upon culture in vitro, but also in vivo after systemic injection in STZ-induced diabetic mouse models. Being nonteratogenic, MDSC can be used directly by systemic injection, and this potential reveals a promising alternative avenue in stem cell-based treatment of beta-cell deficiencies.


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04/10/2017 - Efficacy of stem cells on periodontal regeneration: Systematic review of pre-clinical studies.

Abstract


This systematic review aims to evaluate mesenchymal stem cells (MSC) periodontal regenerative potential in animal models. MEDLINE, EMBASE and LILACS databases were searched for quantitative pre-clinical controlled animal model studies that evaluated the effect of local administration of MSC on periodontal regeneration. The systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement guidelines. Twenty-two studies met the inclusion criteria. Periodontal defects were surgically created in all studies. In seven studies, periodontal inflammation was experimentally induced following surgical defect creation. Differences in defect morphology were identified among the studies. Autogenous, alogenous and xenogenous MSC were used to promote periodontal regeneration. These included bone marrow-derived MSC, periodontal ligament (PDL)-derived MSC, dental pulp-derived MSC, gingival margin-derived MSC, foreskin-derived induced pluripotent stem cells, adipose tissue-derived MSC, cementum-derived MSC, periapical follicular MSC and alveolar periosteal cells. Meta-analysis was not possible due to heterogeneities in study designs. In most of the studies, local MSC implantation was not associated with adverse effects. The use of bone marrow-derived MSC for periodontal regeneration yielded conflicting results. In contrast, PDL-MSC consistently promoted increased PDL and cementum regeneration. Finally, the adjunct use of MSC improved the regenerative outcomes of periodontal defects treated with membranes or bone substitutes. Despite the quality level of the existing evidence, the current data indicate that the use of MSC may provide beneficial effects on periodontal regeneration. The various degrees of success of MSC in periodontal regeneration are likely to be related to the use of heterogeneous cells. Thus, future studies need to identify phenotypic profiles of highly regenerative MSC populations.


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03/23/2017 - Control of dental-derived induced pluripotent stem cells through modified surfaces for dental application.

Abstract


OBJECTIVE:

The aim of this study is to investigate the behaviour of iPSc derived from dental stem cells in terms of initial adhesion, differentiation potential on differently surface-treated titanium disc.

MATERIALS AND METHODS:

iPSc derived from human gingival fibroblasts (hGFs) were established using 4-reprogramming factors transduction with Sendai virus. The hGF-iPSc established in this study exhibited the morphology and growth properties similar to human embryonic stem (ES) cells and expressed pluripotency makers. Alkaline Phosphatase (AP) staining, Embryoid Body (EB) formation and in vitro differentiation and karyotyping further confirmed pluripotency of hGF-iPSc. Then, hGF-iPSc were cultured on machined- and Sandblasted and acid etched (SLA)-treated titanium discs with osteogenic induction medium and their morphological as well as quantitative changes according to different surface types were investigated using Alizrin Red S staining, Scanning electron microscopy (SEM), Flow cytometry and RT-PCR.

RESULTS:

Time-dependent and surface-dependent morphological changes as well as quantitative change in osteogenic differentiation of hGF-iPSc were identified and osteogenic gene expression of hGF-iPSc cultured on SLA-treated titanium disc found to be greater than machined titanium disc, suggesting the fate of hGF-iPSc may be determined by the characteristics of surface to which hGF-iPSc first adhere.

CONCLUSIONS:

iPSc derived from dental stem cell can be one of the most promising and practical cell sources for personalized regenerative dentistry and their morphological change as well as quantitative change in osteogenic differentiation according to different surface types may be further utilized for future clinical application incorporated with dental implant.


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03/07/2017 - Gingival Spheroids Possess Multilineage Differentiation Potential

Abstract


Recently studies have demonstrated HGMSCs as ideal candidates for regenerative study. Interestingly we found that HGMSCs derived spheroids are more potent and maintain the properties of stemness convincingly compared to conventional culture methods. During the culture, GMSCs instinctively accumulated into spheroids and display multipotent STRO-1 and Vimentin-positive cells. Reduced phenotypic expression of CD73, CD105 and, elevated expression STRO-1 and CD-34. Pluripotent nature of S-GMSCs putatively shown the expression of OCT4A, NANOG, SOX-2, SSEA4, TRA-1-60, and TRA-181. Also, levels of protein are much higher in spheroid than dissociated culture. On endothelial induction, spheroid differentiated and developed a vascular structure with positive expression of CD31 and on neuronal induction showed positivity for TUJ1 and E-Cadherin. Importantly, undifferentiated state of S-GMSCs exhibited significant upregulation of aforementioned pluripotent genes and lack of pro-inflammatory cytokines IL-6 and amplified ARF signal confirming that the spheroids are not teratoma formation. However, higher of CAP1, CP, TGFß, OPN, PPAR?, TUJ1 and NESTIN expression observed in spheroids, and minimal expression of the same markers were observed in adherent GMSCs respectively. Ahead of dissociated gingival culture, spheroid provides enhanced viable, pluripotent and, multilineage ability. This study suggested that S-GMSCs increased the chances of therapeutic efficacy in the regenerative applications. This article is protected by copyright. All rights reserved.


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02/06/2017 - Regenerative medicine using dental pulp stem cells for liver diseases.

Abstract

Acute liver failure is a refractory disease and its prognosis, if not treated using liver transplantation, is extremely poor. It is a good candidate for regenerative medicine, where stem cell-based therapies play a central role. Mesenchymal stem cells (MSCs) are known to differentiate into multiple cell lineages including hepatocytes. Autologous cell transplant without any foreign gene induction is feasible using MSCs, thereby avoiding possible risks of tumorigenesis and immune rejection. Dental pulp also contains an MSC population that differentiates into hepatocytes. A point worthy of special mention is that dental pulp can be obtained from deciduous teeth during childhood and can be subsequently harvested when necessary after deposition in a tooth bank. MSCs have not only a regenerative capacity but also act in an anti-inflammatory manner via paracrine mechanisms. Promising efficacies and difficulties with the use of MSC derived from teeth are summarized in this review.

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01/13/2017 - Potential of human dental stem cells in repairing the complete transection of rat spinal cord

Abstract

OBJECTIVE:

The adult spinal cord of mammals contains a certain amount of neural precursor cells, but these endogenous cells have a limited capacity for replacement of lost cells after spinal cord injury. The exogenous stem cells transplantation has become a therapeutic strategy for spinal cord repairing because of their immunomodulatory and differentiation capacity. In addition, dental stem cells originating from the cranial neural crest might be candidate cell sources for neural engineering.

APPROACH:

Human dental follicle stem cells (DFSCs), stem cells from apical papilla (SCAPs) and dental pulp stem cells (DPSCs) were isolated and identified in vitro, then green GFP-labeled stem cells with pellets were transplanted into completely transected spinal cord. The functional recovery of rats and multiple neuro-regenerative mechanisms were explored.

MAIN RESULTS:

The dental stem cells, especially DFSCs, demonstrated the potential in repairing the completely transected spinal cord and promote functional recovery after injury. The major involved mechanisms were speculated below: First, dental stem cells inhibited the expression of interleukin-1ß to reduce the inflammatory response; second, they inhibited the expression of ras homolog gene family member A (RhoA) to promote neurite regeneration; third, they inhibited the sulfonylurea receptor1 (SUR-1) expression to reduce progressive hemorrhagic necrosis; lastly, parts of the transplanted cells survived and differentiated into mature neurons and oligodendrocytes but not astrocyte, which is beneficial for promoting axons growth.

SIGNIFICANCE:

Dental stem cells presented remarkable tissue regenerative capability after spinal cord injury through immunomodulatory, differentiation and protection capacity.

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07/27/2016 - Large, stratified, and mechanically functional human cartilage grown in vitro by mesenchymal condensation

Abstract

The efforts to grow mechanically functional cartilage from human mesenchymal stem cells have not been successful. We report that clinically sized pieces of human cartilage with physiologic stratification and biomechanics can be grown in vitro by recapitulating some aspects of the developmental process of mesenchymal condensation. By exposure to transforming growth factor-ß, mesenchymal stem cells were induced to condense into cellular bodies, undergo chondrogenic differentiation, and form cartilagenous tissue, in a process designed to mimic mesenchymal condensation leading into chondrogenesis. We discovered that the condensed mesenchymal cell bodies (CMBs) formed in vitro set an outer boundary after 5 d of culture, as indicated by the expression of mesenchymal condensation genes and deposition of tenascin. Before setting of boundaries, the CMBs could be fused into homogenous cellular aggregates giving rise to well-differentiated and mechanically functional cartilage. We used the mesenchymal condensation and fusion of CMBs to grow centimeter-sized, anatomically shaped pieces of human articular cartilage over 5 wk of culture. For the first time to our knowledge biomechanical properties of cartilage derived from human mesenchymal cells were comparable to native cartilage, with the Young’s modulus of >800 kPa and equilibrium friction coeffcient of <0.3. We also demonstrate that CMBs have capability to form mechanically strong cartilage–cartilage interface in an in vitro cartilage defect model. The CMBs, which acted as “lego-like” blocks of neocartilage, were capable of assembling into human cartilage with physiologic-like structure and mechanical properties.        

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04/07/2016 - Success of Maxillary Alveolar Defect Repair in Rats Using Osteoblast-Differentiated Human Deciduous Dental Pulp Stem Cells

Abstract

PURPOSE:

The use of cell-based therapies represents one of the most advanced methods for enhancing the regenerative response in craniofacial abnormalities. The main aim of this study was to evaluate the regenerative potential of human dental pulp stem cells, isolated from deciduous teeth, for reconstructing maxillary alveolar defects in Wistar rats.

MATERIALS AND METHODS:

Human deciduous dental pulp stem cells were isolated and stimulated to differentiate into osteoblasts in culture media. Maxillary alveolar defects were created in 60 Wistar rats by a surgical procedure. Then, on the basis of the type of graft used to repair the bone defect, the rats were divided into 6 equal groups: groups 1 and 2, transplantation of iliac bone graft; groups 3 and 4, transplantation of stem cells derived from deciduous dental pulp in addition to collagen matrix; groups 5 and 6, transplantation of just collagen matrix. Then, fetal bone formation, granulation tissue, fibrous tissue, and inflammatory tissue were evaluated by hematoxylin-eosin staining at 1 month (groups 1, 3, and 5) and 2 months (groups 2, 4, and 6) after surgery, and data were analyzed and compared using the Fisher exact test.

RESULTS:

Maximum fetal bone formation occurred in group 2, in which iliac bone graft was inserted into the defect area for 2 months; there also were significant differences among the groups for bone formation (P = .009). In the 1-month groups, there were no significant differences between the control and stem cell-plus-scaffold groups. There were significant differences between the 2-month groups for fetal bone formation only between the control and scaffold groups (P = .026).

CONCLUSIONS:

The study showed that human dental pulp stem cells are an additional cell resource for repairing maxillary alveolar defects in rats and constitute a promising model for reconstruction of human maxillary alveolar defects in patients with cleft lip and palate.


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04/04/2016 - Biomaterials-based strategies for salivary gland tissue regeneration.

Abstract

The salivary gland is a complex, secretory tissue that produces saliva and maintains oral homeostasis. Radiation induced salivary gland atrophy, manifested as "dry mouth" or xerostomia, poses a significant clinical challenge. Tissue engineering recently has emerged as an alternative, long-term treatment strategy for xerostomia. In this review, we summarize recent efforts towards the development of functional and implantable salivary glands utilizing designed polymeric substrates or synthetic matrices/scaffolds. Although the in vitro engineering of a complex implantable salivary gland is technically challenging, opportunities exist for multidisciplinary teams to assemble implantable and secretory tissue modules by combining stem/progenitor cells found in the adult glands with biomimetic and cell-instructive materials.


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04/03/2016 - Mesenchymal stem cells modified with Runt-related transcription factor 2 promote bone regeneration in rabbit mandibular distraction osteogenesis.

Abstract

OBJECTIVE:

This work investigated mesenchymal stem cells (MSCs) modified with Runt-related transcription factor 2 (Runx2) therapy for bone regeneration in rabbit mandibular distraction osteogenesis.

METHODS:

Forty-eight New Zealand mature white rabbits were randomly divided into three groups after the rabbit model of mandibular distraction osteogenesis was established: reconstruction plasmid modified with Runx2 (group A), plasmid without Runx2 (group B), and the same dose of saline as control (group C). At the fifth day of distraction phase, MSCs with reconstruction plasmid modified with adv-hRunx2-gfp were injected into the distraction gap of group A. MSCs with reconstruction plasmid modified with adv-gfp was injected into the distraction gap of group B, whereas group C was injected with the same dose of saline. At 8 weeks after injection, all animals were sacrificed, and the distracted mandibles were harvested. The general imaging histological observation and three-point bending test were used for evaluation.

RESULTS:

CT plain scan and histological analysis confirmed that the amount of new bone forming in the distraction gap of group A was significantly higher than those in groups B and C. Dual-energy X ray and three-point bending test results also showed that the bone mineral density, bone mineral content, and maximum load of the distraction gap of group A were significantly higher than those of groups B and C (P<0.01).

CONCLUSION:

Runx2-ex vivo gene therapy based on MSCs can effectively promote the bone regeneration in rabbit mandibular distraction osteogenesis and shorten the stationary phase. Therefore, reconstruction of craniofacial fracture would be a valuable strategy


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01/06/2016 - Regeneration of mandibular ameloblastoma defect with the help of autologous dental pulp stem cells and buccal pad of fat stromal vascular fraction.

Abstract

Ameloblastoma is benign odontogenic tumor, which is locally aggressive in behavior. Till date, the treatment of choice is resection and reconstruction using a variety of modalities. Inadequate resection may lead to many complications such as bone deformity and dysfunction. This report is about a 14-year-old male with ameloblastoma treated with autologous dental pulp stem cells (DPSCs) and stromal vascular fraction (SVF) and evidence of bone regeneration. Marsupialization was performed; tooth was extracted and sent for DPSC cultivation. On the day of surgery, SVF was processed from buccal pad of fat, and platelet-rich fibrin (PRF) was prepared from patient's peripheral blood. During the procedure, labial plate resection and curating of tumor lining were done. After which, a mesh packed with SyboGraft T-plug, prepared SVF, DPSCs, and PRF were placed over lingual cortex and pressure dressing was done. After the 1(st) month of surgery the postoperative course was uneventful, the wound shrinkage led to exposure of mesh in the intraoral region. Removal of exposed mesh was done. The correction surgery with removal of part of mesh and primary closure was achieved with SyboGraft plug, SVF and PRF. Enhanced bone formation was seen in post-operative OPG and CT Scan after 10(th) month. In this article, we propose an innovative approach to manage these cases by using a combination of autologous DPSC and buccal pad of fat SVF to regenerate a mandibular defect left by the resection of an ameloblastoma with 1.5 year follow-up. We were able to demonstrate bone regeneration using this technique with no recurrence of tumor.


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01/01/2016 - Three-Dimensional Bioprinting Nanotechnologies towards Clinical Application of Stem Cells and Their Secretome in Salivary Gland Regeneration.

Abstract

Salivary gland (SG) functional damage and severe dry mouth (or xerostomia) are commonly observed in a wide range of medical conditions from autoimmune to metabolic disorders as well as after radiotherapy to treat specific head and neck cancers. No effective therapy has been developed to completely restore the SG functional damage on the long-term and reverse the poor quality of life of xerostomia patients. Cell- and secretome-based strategies are currently being tested in vitro and in vivo for the repair and/or regeneration of the damaged SG using (1) epithelial SG stem/progenitor cells from salispheres or explant cultures as well as (2) nonepithelial stem cell types and/or their bioactive secretome. These strategies will be the focus of our review. Herein, innovative 3D bioprinting nanotechnologies for the generation of organotypic cultures and SG organoids/mini-glands will also be discussed. These bioprinting technologies will allow researchers to analyze the secretome components and extracellular matrix production, as well as their biofunctional effects in 3D mini-glands ex vivo. Improving our understanding of the SG secretome is critical to develop effective secretome-based therapies towards the regeneration and/or repair of all SG compartments for proper restoration of saliva secretion and flow into the oral cavity.


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05/12/2015 - Transdifferentiation of Bone Marrow Mesenchymal Stem Cells into the Islet-Like Cells: the Role of Extracellular Matrix Proteins.

Abstract 

Pancreatic islet implantation has been recently shown to be an efficient method of treatment for type 1 diabetes. However, limited availability of donor islets reduces its use. Bone morrow would provide potentially unlimited source of stem cells for generation of insulin-producing cells. This study was performed to evaluate the influence of extracellular matrix proteins like collagen, laminin, and vitronectin on bone marrow mesenchymal stem cells (BM-MSCs) transdifferentiation into islet-like cells (ILCs) in vitro. To our knowledge, this is the first report evaluating the importance of vitronectin in transdifferentiation of BM-MSCs into ILCs. Rat BM-MSCs were induced to ILCs using four-step protocol on plates coated with collagen type IV, laminin type I and vitronectin type I. Quantitative real-time PCR was performed to detect gene expression related to pancreatic ß cell development. The induced cells expressed islet-related genes including: neurogenin 3, neurogenic differentiation 1, paired box 4, NK homeobox factor 6.1, glucagon, insulin 1 and insulin 2. Laminin but not collagen type IV or vitronectin enhanced expression of insulin and promoted formation of islet-like structures in monolayer culture. Laminin triggered transdifferentiation of BM-MSCs into ILCs.

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03/27/2015 - Efficacy of periodontal stem cell transplantation in the treatment of advanced periodontitis.

Abstract


Periodontitis is the most common cause for tooth loss in adults and advanced types affect 10-15% of adults worldwide. The attempts to save tooth and regenerate the periodontal apparatus including cementum, periodontal ligament, and alveolar bone reach to the dental tissue-derived stem cell therapy. Although there have been several periodontitis models suggested, the apical involvement of tooth root is especially challenging to be regenerated and dental stem cell therapy for the state has never been investigated. Three kinds of dental tissue-derived adult stem cells (aDSCs) were obtained from the extracted immature molars of beagle dogs (n = 8), and ex vivo expanded periodontal ligament stem cells (PDLSCs), dental pulp stem cells (DPSCs), and periapical follicular stem cells (PAFSCs) were transplanted into the apical involvement defect. As for the lack of cementum-specific markers, anti-human cementum protein 1 (rhCEMP1) antibody was fabricated and the aDSCs and the regenerated tissues were immunostained with anti-CEMP1 antibody. Autologous PDLSCs showed the best regenerating capacity of periodontal ligament, alveolar bone, and cementum as well as peripheral nerve and blood vessel, which were evaluated by conventional and immune histology, 3D micro-CT, and clinical index. The rhCEMP1 was expressed strongest in PDLSCs and in the regenerated periodontal ligament space. We suggest here the PDLSCs as the most favorable candidate for the clinical application among the three dental stem cells and can be used for treatment of advanced periodontitis where tooth removal was indicated in the clinical cases.





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11/19/2014 - Systematic Review Confirms Safety and Efficacy of Mesenchymal Stem Cells in Treating Disc Degeneration

Introduction: This systematic review is designed to assess the safety and efficacy of mesenchymal stromal/stem cells (MSCs) in the treatment of disc degeneration.

Methods: The researchers conducted a systematic review of peer-reviewed comparative controlled studies to assess the safety and efficacy of MSCs compared to no treatment/saline in animals and human subjects. A total of 24 animal studies met the inclusion criteria, 6 of which reported at least partial randomization of treatment. In these animal studies, 862 discs were treated with MSC injection, and 1,603 discs served as controls. The studies included both small animals (mouse, rat, and rabbit) and larger animals (sheep, dogs, and minipigs). None of the human trials met the inclusion criteria.

Results: Overall, MSC injection significantly inhibited disc degeneration, defined as restoration of disc height index similar to that of control discs and increased expression of proteoglycan or extracellular matrix genes. The majority of studies used bone marrow as the source of MSCs, but efficacy also was demonstrated in studies involving MSCs derived from synovial and adipose tissues. Bone-marrow-derived MSCs demonstrated superior quality of repair compared with other non-MSC treatments (eg, articular chondrocytes and mechanical distraction devices). A greater degree of degeneration was linked to greater efficacy of MSC injection.

The overall complication rate was 2.7%, and complications were only found in rabbit studies. These complications included osteophyte formation anterolaterally to the disc space, which was hypothesized to result from leakage of the MSCs.

Conclusion: MSCs were found to be safe and effective in animal models of disc degeneration. MSC injection increased disc space height in the majority of animal models evaluated in this review. The authors called for randomized clinical trials in humans.




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07/08/2014 - IGF Promotes Cardiac Lineage Induction in vitro by Selective Expansion of Early Mesoderm
While cell based therapies, especially those based on the use of induced pluripotent stem cells (iPSCs), hold great promise for the treatment of a multitude of diseases and disorders, the differentiation of sufficient specific somatic cell types remains a significant problem. Cardiomyocyte production from iPSCs to replace cells lost during myocardial infarction is modest and highly variable [1, 2] and requires further “fine tuning” which may be informed through the study of normal early development [3]. A group led by Sean M. Wu from the Stanford University School of Medicine, CA, USA have now evaluated signaling pathway activation during early cardiac lineage induction [4] to search for factors which can enhance the formation of multipotent cardiac progenitor cells (CPCs) in order to give rise to cardiomyocytes, smooth muscle cells and endothelial cells [5, 6].

Engels et al first assessed 44 factors in differentiating Nkx2.5-eGFP murine ESCs (day 3) for their ability to enhance Nkx2.5+ CPC formation (see Figure). Of these 44 factors, IGF1, IGF2, insulin and Wnt3a all significantly increased CPC formation, while Activin A, BMP2 or BMP4 decreased CPC formation. Positive factors led to a dose-dependent increase in the number of eGFP cells, although the positive effect was only seen at day 3 and not after sorting at day 6. The CPC boosting effect was associated with increases in the expression of cardiac mesoderm- and CPC-specific genes (Mesp1, Isl-1, Nkx2.5, GATA4 and MLC2a), and the production of cardiomyocyte-like cells with proper sarcomeric architecture.

Focusing on how IGFs and Insulin treatment boosts CPC formation, the group observed a significant increase in the expression levels of mesoderm- and endoderm-specific genes (Eomes, Bra, Gata4, Goosecoid, Afp, Hnf1b, Hnf3b and Sox17), whilst ectoderm-specific genes (Nestin, Gbx2, Fgf5 and Pax6) were unchanged or slightly decreased. Further research found that Bra+ mesodermal cells, but not Bra- cells, were highly proliferative following IGF/Insulin treatment, suggesting that these factors may selectively induce mesodermal cell proliferation to boost CPC formation. AKT phosphorylation, a mediator of IGF signaling [27], was also selectively induced in Bra+ cells following IGF/insulin treatment. Selective inhibition of Akt, as well as PI3K and mTOR, signalling during differentiation blocked IGF/insulin-induced formation of eGFP+ CPCs, while Akt inhibition also reduced the frequency of Brachyury/Ki-67-double-positive cells suggesting that IGF signaling through PI3K, Akt and mTOR can enhance mesodermal cell proliferation which allows increased CPC formation.

The authors note that this is the first study to show a direct role for IGF/Insulin in the mesodermal differentiation of ESCs, via PI3K, Akt and mTOR signalling-mediated expansion of Bra+ cells during differentiation. This will not only inform us on early developmental processes which may occur in vivo, but will also aid to improve cardiac differentiation strategies towards possible clinical use. Hopefully this research can be taken forward into human pluripotent stem cell types in order to amplify the production of much needed cells which will be required for effective cell therapy.

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07/08/2014 - Biological Alchemy: Engineering Bone and Fat From Fat-Derived Stem Cells.
Abstract

Adipose tissue contains a population of pluripotent stem cells capable of differentiating along multiple mesenchymal cell lineages. In this study the authors isolated these fat-derived stem cells successfully from Lewis rats and induced differentiation along adipogenic and osteogenic lineages in vitro and in vivo. Induction was stimulated by exposing stem cells to lineage-specific induction factors. Adipocyte-inducing media contained dexamethasone, insulin, and isobutyl-methylxanthine. Osteoblast inducing media contained dexamethasone, beta-glycerophosphate, and ascorbic acid. Undifferentiated stem cells were maintained in minimal essential media alpha and fetal bovine serum. At 10 days, cells cultured in adipogenic media differentiated into adipocytes in vitro, as evidenced by positive Oil red O staining of lipid vacuoles. At 21 days, cells cultured in osteogenic media differentiated into osteoblasts in vitro as demonstrated by Alizarin red staining of a calcified extracellular matrix and immunohistochemical staining for osteocalcin. Differentiated cells were seeded at a density of 5 x 106 cells onto 15 x 15-mm polyglycolic acid grafts and implanted subcutaneously into three groups of Lewis rats: Group I contained undifferentiated stem cell grafts, group II contained adipocyte grafts, and group III contained osteoblast grafts. At weeks 4 and 8, in vivo fat formation was demonstrated in group II rats, as confirmed by Oil red O staining. At 8 weeks, group III rats demonstrated in vivo bone formation, as confirmed by the presence of osteocalcin on immunohistochemistry and the characteristic morphology of bone on hematoxylin-eosin staining. Group I rats demonstrated no in vivo bone or fat formation at either time interval. These results demonstrate the ability to isolate pluripotent stem cells from adipose tissue, to induce their differentiation into osteoblasts and adipocytes in vitro, and to form bone and fat subsequently in vivo. This is the first published report of in vivo bone formation from fat-derived stem cells. These cells may eventually serve as a readily available source of autologous stem cells for the engineering of bone and fat.

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03/14/2014 - Mesenchymal Stem Cells Regenerate Tissue in Knee after Meniscectomy
Background: There are limited treatment options for tissue restoration and the prevention of degenerative changes in the knee. Stem cells have been a focus of intense preclinical research into tissue regeneration but limited clinical investigation. In a randomized, double-blind, controlled study, the safety of the intra-articular injection of human mesenchymal stem cells into the knee, the ability of mesenchymal stem cells to promote meniscus regeneration following partial meniscectomy, and the effects of mesenchymal stem cells on osteoarthritic changes in the knee were investigated.

Methods: A total of fifty-five patients at seven institutions underwent a partial medial meniscectomy. A single superolateral knee injection was given within seven to ten days after the meniscectomy. Patients were randomized to one of three treatment groups: Group A, in which patients received an injection of 50 × 106 allogeneic mesenchymal stem cells; Group B, 150 × 106 allogeneic mesenchymal stem cells; and the control group, a sodium hyaluronate (hyaluronic acid/hyaluronan) vehicle control. Patients were followed to evaluate safety, meniscus regeneration, the overall condition of the knee joint, and clinical outcomes at intervals through two years. Evaluations included sequential magnetic resonance imaging (MRI).

Results: No ectopic tissue formation or clinically important safety issues were identified. There was significantly increased meniscal volume (defined a priori as a 15% threshold) determined by quantitative MRI in 24% of patients in Group A and 6% in Group B at twelve months post meniscectomy (p = 0.022). No patients in the control group met the 15% threshold for increased meniscal volume. Patients with osteoarthritic changes who received mesenchymal stem cells experienced a significant reduction in pain compared with those who received the control, on the basis of visual analog scale assessments.

Conclusions: There was evidence of meniscus regeneration and improvement in knee pain following treatment with allogeneic human mesenchymal stem cells. These results support the study of human mesenchymal stem cells for the apparent knee-tissue regeneration and protective effects.

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02/28/2014 - Effect of Stem Cells on Renal Recovery in Animal Model
Abstract

Background Untreated obstructive uropathy produces irreversible renal damage and is an important cause of pediatric renal insufficiency. This study was designed to evaluate the effects of stem cell injection on morphological and pathological changes in the rat kidneys with partial unilateral upper ureteric obstruction (PUUUO). Methods Wistar rats (n = 30) were operated upon to create a PUUUO by the psoas hitch method and were randomized into Group I (control, n = 15) and Group II (stem cell, n = 15); at day 5, 10 and 15, a subgroup of rats (n = 5) from each group was killed and the kidneys harvested. Pathological and morphological changes in the harvested kidneys were studied and compared between the two groups.

Results Morphologically, at day 15, Group II had significantly (p = 0.04) greater cortical thickness (0.48 ± 0.17 vs. 0.38 ± 0.09 mm). Histologically, at day 5, Group II had significantly (p = 0.032) lower peri-pelvic fibrosis. Group II group showed greater peri-pelvic inflammation as compared to Group I (p = 0.05). At day 10, lower grades of peri-pelvic fibrosis (p = 0.08), interstitial fibrosis (p = 0.037) and tubular atrophy (p = 0.05) were seen in the Group II. At day 15, Group II demonstrated significantly lower parenchymal loss (p = 0.037), glomerulosclerosis (p = 0.08), interstitial fibrosis (p = 0.08), tubular atrophy (p = 0.08) and peri-pelvic fibrosis (p = 0.08).

Conclusions In a rat model of PUUUO, stem cell injection prevented detrimental changes in renal pathology and preserved renal parenchymal mass.

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02/21/2014 - Thalassemia Major Cured Utilizing Stem Cells in Umbilical Cord Blood
Abstract

Allogeneic hematopoietic cell transplantation (HCT) has been successfully used as replacement therapy for patients with aplastic anemia and hemoglobinopathies. Both autologous and allogeneic HCT following high-dose chemotherapy can correct manifestations of autoimmune diseases. The impressive allogeneic graft-versus-tumor effects seen in patients given HCT for hematological malignancies have stimulated trials of allogeneic immunotherapy in patients with otherwise refractory metastatic solid tumors. This session will update the status of HCT in the treatment of benign hematological diseases and solid tumors. In Section I, Dr. Rainer Storb reviews the development of nonmyeloablative conditioning for patients with severe aplastic anemia who have HLA-matched family members. He also describes the results in patients with aplastic anemia given HCT from unrelated donors after failure of responding to immunosuppressive therapy. The importance of leuko-poor and in vitro irradiated blood product transfusions for avoiding graft rejection will be discussed. In Section II, Dr. Guido Lucarelli reviews the status of marrow transplantation for thalassemia major and updates results obtained in children with class I and class II severity of thalassemia. He also describes results of new protocols for class III patients and efforts to extend HCT to thalassemic patients without HLA-matched family members. In Section III, Dr. Peter McSweeney reviews the current status of HCT for severe autoimmune diseases. He summarizes the results of autologous HCT for systemic sclerosis, multiple sclerosis, rheumatoid arthritis, and systemic lupus erythematosus, and reviews the status of planned Phase III studies for autologous HCT for these diseases in North America and Europe. He also discusses a possible role of allogeneic HCT in the treatment of these diseases. In Section IV, Dr. Richard Childs discusses the development and application of nonmyeloablative HCT as allogeneic immunotherapy for treatment-refractory solid tumors. He reviews the results of pilot clinical trials demonstrating graft-versus-solid tumor effects in a variety of metastatic cancers and describes efforts to characterize the immune cell populations mediating these effects, as well as newer methods to target the donor immune system to the tumor.

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02/17/2014 - Scalable 3D Culture System for Stem Cell Expansion and Differentiation
Abstract

Human pluripotent stem cells (hPSCs), including human embryonic stem cells and induced pluripotent stem cells, are promising for numerous biomedical applications, such as cell replacement therapies, tissue and whole-organ engineering, and high-throughput pharmacology and toxicology screening. Each of these applications requires large numbers of cells of high quality; however, the scalable expansion and differentiation of hPSCs, especially for clinical utilization, remains a challenge. We report a simple, defined, efficient, scalable, and good manufacturing practice-compatible 3D culture system for hPSC expansion and differentiation. It employs a thermoresponsive hydrogel that combines easy manipulation and completely defined conditions, free of any human- or animal-derived factors, and entailing only recombinant protein factors. Under an optimized protocol, the 3D system enables long-term, serial expansion of multiple hPSCs lines with a high expansion rate ('20-fold per 5-d passage, for a 1072-fold expansion over 280 d), yield ('2.0 × 107 cells per mL of hydrogel), and purity ('95% Oct4+), even with single-cell inoculation, all of which offer considerable advantages relative to current approaches. Moreover, the system enabled 3D directed differentiation of hPSCs into multiple lineages, including dopaminergic neuron progenitors with a yield of '8 × 107 dopaminergic progenitors per mL of hydrogel and '80-fold expansion by the end of a 15-d derivation. This versatile system may be useful at numerous scales, from basic biological investigation to clinical development.

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01/24/2014 - Mesenchymal Stem Cells in Synovial Fluid Increase After Meniscus Injury
Background Although relatively uncommon, spontaneous healing from a meniscus injury has been observed even within the avascular area. This may be the result of the existence of mesenchymal stem cells in synovial fluid.

Questions/purposes The purpose of this study was to investigate whether mesenchymal stem cells existed in the synovial fluid of the knee after meniscus injury.

Methods Synovial fluid was obtained from the knees of 22 patients with meniscus injury just before meniscus surgery and from 8 volunteers who had no history of knee injury. The cellular fraction of the synovial fluid was cultured for 14 days followed by analysis for multilineage potential and presentation of surface antigens characteristic of mesenchymal stem cells. Colony-forming efficiency and proliferation potential were also compared between the two groups.

Results

Cells with characteristics of mesenchymal stem cells were observed in the synovial fluid of injured knees to a much greater degree than in uninjured knees. The colony-forming cells derived from the synovial fluid of the knee with meniscus injury had multipotentiality and surface epitopes identical to mesenchymal stem cells. The average number of colony formation, obtained from 1 mL of synovial fluid, in meniscus-injured knees was 250, higher than that from healthy volunteers, which was 0.5 (p < 0.001). Total colony number per synovial fluid volume was positively correlated with the postinjury period (r = 0.77, p < 0.001).

Conclusions Mesenchymal stem cells were found to exist in synovial fluid from knees after meniscus injury. Mesenchymal stem cells were present in higher numbers in synovial fluid with meniscus injury than in normal knees. Total colony number per synovial fluid volume was positively correlated with the postinjury period.

Clinical Relevance Our current human study and previous animal studies suggest the possibility that mesenchymal stem cells in synovial fluid increase after meniscus injury contributing to spontaneous meniscus healing.

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01/08/2014 - Mesenchymal stem cells results in improve viability and function of human hepatocytes
Abstract:

Hepatocyte transplantation is becoming an accepted therapy for acute liver failure, either as a bridge to liver regeneration or to organ transplantation. Hepatocytes provide liver function in place of the failing organ. The maintenance of sufficient viability and function of the transplanted hepatocytes is a concern. There isrecent interest in mesenchymal stem cells (MSCs) for the provision of structural and trophic support tohepatocytes but few studies which use primary human hepatocytes. The aim of this study was to investigate if co-culture of human MSCs with cryopreserved human hepatocytes may improve their function and viability, thus with potential for cellular therapy of liver disease. MSCs were isolated from human umbilical cordor adipose tissue and hepatocytes from donor organs unsuitable for transplantation. MSCs and hepatocytes were co-cultured in both direct and indirect contact. Conditioned medium (CM) from co-cultured MSCs and hepatocytes was also used on hepatocytes. Viability and liver-specific function were compared between test and controls. Human hepatocytes which were co-cultured directly with MSCs demonstrated improved production of albumin from day 5 to day 25 of culture. This effect was most prominent at day 15 when albumin production in co-culture was 10x that of control monoculture. Likewise urea production was improved in co-culture from day 5 to 25. Indirect co-culture demonstrated improved albumin production by day 4 (1107ng/ml) versus hepatocyte monoculture (940ng/ml). Hepatocytes in CM demonstrated improved function but not to statistical significance. The viability of co-cultured hepatocytes was superior to that of monocultured cells with up to a 16% improvement.

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12/26/2013 - Adult rat retinal ganglion cells and glia can be printed by piezoelectric inkjet printing
Abstract

We have investigated whether inkjet printing technology can be extended to print cells of the adult rat central nervous system (CNS), retinal ganglion cells (RGC) and glia, and the effects on survival and growth of these cells in culture, which is an important step in the development of tissue grafts for regenerative medicine, and may aid in the cure of blindness. We observed that RGC and glia can be successfully printed using a piezoelectric printer. Whilst inkjet printing reduced the cell population due to sedimentation within the printing system, imaging of the printhead nozzle, which is the area where the cells experience the greatest shear stress and rate, confirmed that there was no evidence of destruction or even significant distortion of the cells during jet ejection and drop formation. Importantly, the viability of the cells was not affected by the printing process. When we cultured the same number of printed and non-printed RGC/glial cells, there was no significant difference in cell survival and RGC neurite outgrowth. In addition, use of a glial substrate significantly increased RGC neurite outgrowth, and this effect was retained when the cells had been printed. In conclusion, printing of RGC and glia using a piezoelectric printhead does not adversely affect viability and survival/growth of the cells in culture. Importantly, printed glial cells retain their growth-promoting properties when used as a substrate, opening new avenues for printed CNS grafts in regenerative medicine.

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12/13/2013 - Toward Salivary Gland Stem Cell Regeneration
Abstract

Head and neck cancer is the sixth most common cancer worldwide, resulting in ' 640,000 cases. Most of these patients have irreversible damage to their salivary glands due to irradiation therapy, which typically leads to significant decrease in quality of life. In the last 2 decades, several strategies have been suggested to overcome this problem; however, no biologically based treatments are available. In the past few years, the authors of the present article and other researchers have focused on a new strategy of re-implantation of autologous salivary gland cells into the residual irradiated salivary glands. This article reviews the current prospective of the irradiation-induced salivary gland impairment mechanisms and the envisioned therapeutic modalities based on stem cell therapy

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11/25/2013 - The regulation of growth and metabolism of kidney stem cells with regional specificity using extracellular matrix derived from kidney
Native extracellular matrix (ECM) that is secreted and maintained by resident cells is of great interest for cell culture and cell delivery. We hypothesized that specialized bioengineered niches for stem cells can be established using ECM-derived scaffolding materials. Kidney was selected as a model system because of the high regional diversification of renal tissue matrix. By preparing the ECM from three specialized regions of the kidney (cortex, medulla, and papilla; whole kidney, heart, and bladder as controls) in three forms: (i) intact sheets of decellularized ECM, (ii) ECM hydrogels, and (iii) solubilized ECM, we investigated how the structure and composition of ECM affect the function of kidney stem cells (with mesenchymal stem cells, MSCs, as controls). All three forms of the ECM regulated KSC function, with differential structural and compositional effects. KSCs cultured on papilla ECM consistently displayed lower proliferation, higher metabolic activity, and differences in cell morphology, alignment, and structure formation as compared to KSCs on cortex and medulla ECM, effects not observed in corresponding MSC cultures. These data suggest that tissue- and region-specific ECM can provide an effective substrate for in vitro studies of therapeutic stem cells. Click Here to Read the Full Text
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11/25/2013 - Metabolically active human brown adipose tissue derived stem cells

ABSTRACT:

Brown adipose tissue (BAT) plays a key role in the evolutionarily conserved mechanisms underlying energy homeostasis in mammals. It is characterized by fat vacuoles 5-10 microns in diameter and expression of uncoupling protein 1 (UCP1), central to the regulation of thermogenesis. In the human newborn, BAT depots are typically grouped around the vasculature and solid organs. These depots maintain body temperature during cold exposure by warming the blood before its distribution to the periphery. They also ensure an optimal temperature for biochemical reactions within solid organs. BAT had been thought to involute throughout childhood and adolescence. Recent studies, however, have confirmed the presence of active brown adipose tissue in adult humans with depots residing in cervical, supraclavicular, mediastinal, paravertebral and suprarenal regions. While human pluripotent stem cells have been differentiated into functional brown adipocytes in vitro and brown adipocyte progenitor cells have been identified in murine skeletal muscle and white adipose tissue, multipotent metabolically active brown adipose tissue derived stem cells from a single depot have not been identified in adult humans to date. Here we demonstrate a clonogenic population of metabolically active brown adipose tissue stem cells residing in adult humans that can: (1) be expanded in vitro; (2) exhibit multi-lineage differentiation potential; and (3) functionally differentiate into metabolically active brown adipocytes. Our study defines a new target stem cell population that can be activated to restore energy homeostasis in vivo for the treatment of obesity and related metabolic disorders.

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11/25/2013 - Combined effects of chemical priming and mechanical stimulation on mesenchymal stem cell differentiation on nanofiber scaffolds

Abstract:

Functional tissue engineering of connective tissues such as the anterior cruciate ligament (ACL) remains a significant clinical challenge, largely due to the need for mechanically competent scaffold systems for grafting, as well as a reliable cell source for tissue formation. We have designed an aligned, polylactide-co-glycolide (PLGA) nanofiber-based scaffold with physiologically relevant mechanical properties for ligament regeneration. The objective of this study is to identify optimal tissue engineering strategies for fibroblastic induction of human mesenchymal stem cells (hMSC), testing the hypothesis that basic fibroblast growth factor (bFGF) priming coupled with tensile loading will enhance hMSC-mediated ligament regeneration. It was observed that compared to the unloaded, as well as growth factor-primed but unloaded controls, bFGF stimulation followed by physiologically relevant tensile loading enhanced hMSC proliferation, collagen production and subsequent differentiation into ligament fibroblast-like cells, upregulating the expression of types I and III collagen, as well as tenasin-C and tenomodulin. The results of this study suggest that bFGF priming increases cell proliferation, while mechanical stimulation of the hMSCs on the aligned nanofiber scaffold promotes fibroblastic induction of these cells. In addition to demonstrating the potential of nanofiber scaffolds for hMSC-mediated functional ligament tissue engineering, this study yields new insights into the interactive effects of chemical and mechanical stimuli on stem cell differentiation.

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11/18/2013 - Stem Cells Used to Limit Damage of Traumatic Brain Injury (TBI)
Intravenous Multipotent Adult Progenitor Cell Therapy Attenuates Activated Microglial/Macrophage Response and Improves Spatial Learning After Traumatic Brain Injury

Abstract

We previously demonstrated that the intravenous delivery of multipotent adult progenitor cells (MAPCs) after traumatic brain injury (TBI) in rodents provides neuroprotection by preserving the blood-brain barrier and systemically attenuating inflammation in the acute time frame following cell treatment; however, the long-term behavioral and anti-inflammatory effects of MAPC administration after TBI have yet to be explored. We hypothesized that the intravenous injection of MAPCs after TBI attenuates the inflammatory response (as measured by microglial morphology) and improves performance at motor tasks and spatial learning (Morris water maze [MWM]). MAPCs were administered intravenously 2 and 24 hours after a cortical contusion injury (CCI). We tested four groups at 120 days after TBI: sham (uninjured), injured but not treated (CCI), and injured and treated with one of two concentrations of MAPCs, either 2 million cells per kilogram (CCI-2) or 10 million cells per kilogram (CCI-10). CCI-10 rats showed significant improvement in left hind limb deficit on the balance beam. On the fifth day of MWM trials, CCI-10 animals showed a significant decrease in both latency to platform and distance traveled compared with CCI. Probe trials revealed a significant decrease in proximity measure in CCI-10 compared with CCI, suggesting improved memory retrieval. Neuroinflammation was quantified by enumerating activated microglia in the ipsilateral hippocampus. We observed a significant decrease in the number of activated microglia in the dentate gyrus in CCI-10 compared with CCI. Our results demonstrate that intravenous MAPC treatment after TBI in a rodent model offers long-term improvements in spatial learning as well as attenuation of neuroinflammation.

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11/15/2013 - GMP-level adipose stem cells combined with computer-aided manufacturing to reconstruct mandibular ameloblastoma resection defects
Source

Institute of Biomedical Technology, University of Tampere, Tampere, Finland ; Department of Eye, Ear and Oral Diseases, Tampere University Hospital, Tampere, Finland.

BACKGROUND: The current management of large mandibular resection defects involves harvesting of autogenous bone grafts and repeated bending of generic reconstruction plates. However, the major disadvantage of harvesting large autogenous bone grafts is donor site morbidity and the major drawback of repeated reconstruction plate bending is plate fracture and difficulty in reproducing complex facial contours. The aim of this study was to describe reconstruction of three mandibular ameloblastoma resection defects using tissue engineered constructs of beta-tricalcium phosphate (ß-TCP) granules, recombinant human bone morphogenetic protein-2 (rhBMP-2), and Good Manufacturing Practice (GMP) level autologous adipose stem cells (ASCs) with progressively increasing usage of computer-aided manufacturing (CAM) technology.

MATERIALS AND METHODS: Patients' three-dimensional (3D) images were used in three consecutive patients to plan and reverse-engineer patient-specific saw guides and reconstruction plates using computer-aided additive manufacturing. Adipose tissue was harvested from the anterior abdominal walls of three patients before resection. ASCs were expanded ex vivo over 3 weeks and seeded onto a ß-TCP scaffold with rhBMP-2. Constructs were implanted into patient resection defects together with rapid prototyped reconstruction plates.

RESULTS: All three cases used one step in situ bone formation without the need for an ectopic bone formation step or vascularized flaps. In two of the three patients, dental implants were placed 10 and 14 months following reconstruction, allowing harvesting of bone cores from the regenerated mandibular defects. Histological examination and in vitro analysis of cell viability and cell surface markers were performed and prosthodontic rehabilitation was completed.

DISCUSSION: Constructs with ASCs, ß-TCP scaffolds, and rhBMP-2 can be used to reconstruct a variety of large mandibular defects, together with rapid prototyped reconstruction hardware which supports placement of dental implants.

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06/25/2013 - Engineering bone tissue substitutes from human induced pluripotent stem cells.
Abstract:
Congenital defects, trauma, and disease can compromise the integrity and functionality of the skeletal system to the extent requiring implantation of bone grafts. Engineering of viable bone substitutes that can be personalized to meet specific clinical needs represents a promising therapeutic alternative. The aim of our study was to evaluate the utility of human-induced pluripotent stem cells (hiPSCs) for bone tissue engineering. We first induced three hiPSC lines with different tissue and reprogramming backgrounds into the mesenchymal lineages and used a combination of differentiation assays, surface antigen profiling, and global gene expression analysis to identify the lines exhibiting strong osteogenic differentiation potential. We then engineered functional bone substitutes by culturing hiPSC-derived mesenchymal progenitors on osteoconductive scaffolds in perfusion bioreactors and confirmed their phenotype stability in a subcutaneous implantation model for 12 wk. Molecular analysis confirmed that the maturation of bone substitutes in perfusion bioreactors results in global repression of cell proliferation and an increased expression of lineage-specific genes. These results pave the way for growing patient-specific bone substitutes for reconstructive treatments of the skeletal system and for constructing qualified experimental models of development and disease. Click Here to Read the Full Text
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03/05/2012 - Scientists Repair Heart Attack Damage Using Patient's Own Stem Cells To Regrow Healthy Heart Muscle
Details of a small clinical trial published in The Lancet on Tuesday reveal how scientists helped patients with hearts damaged by heart attack to re-grow healthy heart muscle and reduce scar tissue with an infusion of stem cells taken from the patients' own hearts. The full article can be found here: http://www.medicalnewstoday.com/articles/241592.php
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01/19/2012 - Anti-aging potential of young stem cells demonstrated in University of Pittsburgh study
University of Pittsburgh School of Medicine study suggests banking stem cells when they are young for use in regenerative therapies. For the full published research, read more.

Muscle-derived stem/progenitor cell dysfunction limits healthspan and lifespan in a murine progeria model

Nature Communications 3, Article number: 608 doi:10.1038/ncomms1611 Received 26 July 2011 Accepted 24 November 2011 Published 03 January 2012

Abstract

With ageing, there is a loss of adult stem cell function. However, there is no direct evidence that this has a causal role in ageing-related decline. We tested this using muscle-derived stem/progenitor cells (MDSPCs) in a murine progeria model. Here we show that MDSPCs from old and progeroid mice are defective in proliferation and multilineage differentiation. Intraperitoneal administration of MDSPCs, isolated from young wild-type mice, to progeroid mice confer significant lifespan and healthspan extension. The transplanted MDSPCs improve degenerative changes and vascularization in tissues where donor cells are not detected, suggesting that their therapeutic effect may be mediated by secreted factor(s). Indeed, young wild-type-MDSPCs rescue proliferation and differentiation defects of aged MDSPCs when co-cultured. These results establish that adult stem/progenitor cell dysfunction contributes to ageing-related degeneration and suggests a therapeutic potential of post-natal stem cells to extend health.

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09/02/2011 - Isolation of mesenchymal stem cells from the mandibular marrow aspirates.

Department of Oral and Maxillofacial Surgery, Asan Medical Center, College of Medicine, Ulsan University, Seoul, Korea.

OBJECTIVE:

The aim of this study was to determine if mesenchymal stem cells (MSCs) could be obtained from mandible marrow aspirates.

STUDY DESIGN:

In 5 patients, 10 mL marrow aspirates were obtained from both the mandible and the iliac crest. Second passage MSCs were characterized by fluorescence-activated cell sorting (FACS) analysis using MSC-specific cell surface marker, and fifth-passage cells were differentiated into 3 mesenchymal tissues in vitro.

RESULTS:

Average total cell yields of MSCs were 2.8 ± 1.8 × 10(5) per 10 mL marrow aspirates from the mandible. Immunophenotypes of MSCs isolated from the mandible and iliac crest were highly similar, as indicated by FACS analysis. Differentiation into mesodermal cell types, such as osteocytes, chondrocytes, and adipocytes, was successfully achieved in all MSC isolates from all aspirates.

The MSCs can be isolated from the mandibular aspirates, providing an alternative accessible source of MSCs for the treatment of future dental and craniomaxillofacial diseases.

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09/02/2011 - Dental stem cells for craniofacial tissue engineering.

Source

Researcher, Laboratório de Farmacologia e Biocompatibilidade Celular, Faculdade de Medicina Dentária, Universidade do Porto, Porto, Portugal.

Abstract

This article focuses on the biological characterization and discussion of the potential application of oral-derived adult stem cells for craniofacial tissue engineering applications. The authors reviewed experimental (in vitro and in vivo) and clinical reports regarding the isolation, characterization, modulation, and translational clinical application of human precursor cell populations derived from postnatal dental tissues. Five different human dental stem/progenitor cell populations have been isolated and characterized. These postnatal populations present mesenchymal stem cell-like characteristics and enjoy forceful capabilities regarding the differentiation into odontogenic/osteogenic lineages, supporting evidence-in preclinical and clinical trials-for the regeneration of oral/dental tissues.

Copyright © 2011 Mosby, Inc. All rights reserved.

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07/30/2011 - Bone marrow stromal cells produce long-term pain relief in rat models of persistent pain.
Stem Cells. 2011 Aug;29(8):1294-303. doi: 10.1002/stem.667.

Source

Department of Neural and Pain Sciences, Dental School, Baltimore, Maryland, USA; Program in Neuroscience, University of Maryland, Baltimore, Maryland, USA.

Abstract

Chronic pain conditions are difficult to treat and are major health problems. Bone marrow stromal cells (BMSCs) have generated considerable interest as a candidate for cell-based therapy. BMSCs are readily accessible and are easy to isolate and expand ex vivo. Clinical studies show that direct injection of BMSCs does not produce unwanted side effects and is well tolerated and safe. Here, we show that a single systemic (intravenous) or local injection (into the lesion site) of rat primary BMSCs reversed pain hypersensitivity in rats after injury and that the effect lasted until the conclusion of the study at 22 weeks. The pain hypersensitivity was rekindled by naloxone hydrochloride, an opioid receptor antagonist that acts peripherally and centrally, when tested at 1-5 weeks after BMSC infusion. In contrast, naloxone methiodide, a peripherally acting opioid receptor antagonist, only rekindled hyperalgesia in the first 3 weeks of BMSC treatment. Focal downregulation of brainstem mu opioid receptors by RNA interference (RNAi) reversed the effect of BMSCs, when RNAi was introduced at 5- but not 1-week after BMSC transplantation. Thus, BMSCs produced long-term relief of pain and this effect involved activation of peripheral and central opioid receptors in distinct time domains. The findings prompt studies to elucidate the cellular mechanisms of the BMSC-induced pain relieving effect and translate these observations into clinical settings. STEM CELLS 2011;29:1294-1303.

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07/30/2011 - Induced Migration of Dental Pulp Stem Cells for in vivo Pulp Regeneration.
J Dent Res. 2011 Aug;90(8):1013-8. Epub 2011 May 17.

Center for Craniofacial Regeneration (CCR).

Dental pulp has intrinsic capacity for self-repair. However, it is not clear whether dental pulp cells can be recruited endogenously for regenerating pulp tissues, including mineralizing into dentin. This work is based on a hypothesis that dental pulp stem/progenitor cells can be induced to migrate by chemotactic cytokines and act as endogenous cell sources for regeneration and mineralization. Dental stem cells (DSCs) were isolated from adult human tooth pulp and seeded on the surfaces of 3D collagen gel cylinders that were incubated in chemically defined media with stromal-derived factor-1a (SDF1), basic fibroblast growth factor (bFGF), or bone morphogenetic protein-7 (BMP7). Significantly more cells were recruited into collagen gel by SDF1 or bFGF than without cytokines in 7 days, whereas BMP7 had little effect on cell recruitment. BMP7, however, was highly effective, equally to dexamethasone, in orchestrating mineralization of cultured DSCs. Cell membrane receptors for SDF1, bFGF, and BMP7 were up-regulated in treated DSCs. Upon in vivo delivery, bFGF induced re-cellularization and re-vascularization in endodontically treated human teeth implanted into the dorsum of rats. Thus, endogenous dental pulp cells, including stem/progenitor cells, may be recruited and subsequently differentiated by chemotaxis of selective cytokines in the regeneration of dental pulp.

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05/01/2011 - Mesenchymal stem cells derived from dental tissues.
Int Endod J. 2011 Apr 8. doi: 10.1111/j.1365-2591.2011.01877.x.

Cell Therapy Unit. Hospital Universitary Virgen de la Arrixaca, Faculty of Medicine, University of Murcia, Murcia Institute of Neurosciences, University Miguel Hernández, Alicante, Spain.

Mesenchymal stem cells derived from dental tissues. International Endodontic Journal. ABSTRACT: Regeneration of tissues occurs naturally due to the existence of stem cells with the capacity to self-regenerate and differentiate; however, regenerative capacity decreases with age, and in many cases, regeneration is not sufficient to repair the damage produced by degenerative, ischaemic, inflammatory, or tumour-based diseases. In the last decade, advances have been made in the understanding of stem cells, the genes that control the alternative fates of quiescence and differentiation, and the niches that provide specific signals that modulate cell fate decisions. Embryonic stem-cell research is shedding light on the secrets of development. Adult stem cells (AS cells) are available from several sources. Bone marrow and connective tissue have been used in preliminary clinical trials for regenerative therapy. Recently, several types of AS cells have been isolated from teeth, including dental pulp stem cells, stem cells from human exfoliated deciduous teeth, periodontal ligament stem cells, dental follicle progenitor stem cells and stem cells from apical papilla. Preliminary data suggest that these cells have the capacity to differentiate into osteoblasts, adipocytes, chondrocytes and neural cells. If confirmed, these data would support the use of these cells, which are easily obtained from extracted teeth, in dental therapies, including in regenerative endodontics, providing a new therapeutic modality.

© 2011 International Endodontic Journal.

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03/07/2011 - Histologic and histomorphometric evaluation of an allograft stem cell-based matrix sinus augmentation procedure.

Int J Oral Maxillofac Implants. 2011 Jan-Feb;26(1):123-31.

Gonshor A, McAllister BS, Wallace SS, Prasad H.

Faculty of Dentistry, McGill University, Montreal, Quebec, Canada. arongonshor@gmail.com

Abstract

PURPOSE: Long-term success of dental implants has been demonstrated when placed simultaneously with or after a sinus augmentation procedure. However, optimal bone formation can be from 6 to 9 months or longer with grafting materials other than autogenous bone. For this reason, there is interest in any surgical technique that does not require autogenous bone harvesting, yet results in sufficient bone formation within a relatively short time frame.

MATERIALS AND METHODS: This study evaluated and compared bone formation following sinus-augmentation procedures using either an allograft cellular bone matrix (ACBM), containing native mesenchymal stem cells and osteoprogenitors, or conventional allograft (CA).

RESULTS: Histomorphometric analysis of the ACBM grafts revealed average vital bone content of 32.5% ± 6.8% to residual graft content of 4.9% ± 2.4% for the 21 sinuses in the study, at an average healing period of 3.7 ± 0.6 months. Results for the CA, in the same time frame, were average vital bone content of 18.3% ± 10.6% to residual graft content of 25.8% ± 13.4%. A comparison of ACBM and CA grafts, for both vital and residual bone contents, showed P values of .003 and .002, respectively, indicating a statistically significant difference between the groups.

CONCLUSION: The high percentage of vital bone content, after a relatively short healing phase, may encourage a more rapid initiation of implant placement or restoration when a cellular grafting approach is considered.

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03/07/2011 - Human deciduous teeth dental pulp cells with basic fibroblast growth factor enhance wound healing of skin defect.

J Craniofac Surg. 2011 Mar;22(2):438-42.

Nishino Y, Ebisawa K, Yamada Y, Okabe K, Kamei Y, Ueda M.

From the Departments of *Oral and Maxillofacial Surgery and †Plastic and Reconstructive Surgery, Nagoya University Graduate School of Medicine; and ‡Center for Genetic and Regenerative Medicine, Nagoya University School of Medicine, Nagoya, Japan.

Abstract

In this research, we examined the effect on wound healing applying basic fibroblast growth factor (b-FGF) that is approved for clinical use to enhance wound healing and human deciduous teeth dental pulp cells (hDPCs) in clinics, but that have been attracting attention as a novel stem cell source in recent years. Human deciduous teeth were harvested from healthy volunteers, and hDPCs were isolated. We used a nude mouse full-thickness skin defect model and evaluated wound healing by macroscopic view and histologic and histomorphometric analysis. The mice were randomly divided into 4 groups: phosphate-buffered saline-treated group (control group), b-FGF-treated group (b-FGF group), hDPC-treated group (hDPC group), and hDPC and b-FGF-treated group (hDPC/b-FGF group). Basic fibroblast growth factor and hDPC groups accelerated wound healing compared with the control group. There was no statistically significant difference in wound healing observed between the hDPC and b-FGF groups. The hDPC/b-FGF group demonstrated accelerated wound healing compared with other groups. At day 14, PKH26-positive cells were surrounded by human type I collagen in hDPC and hDPC/b-FGF groups in immunohistologic evaluation. Significantly increased collagen fibril areas in wound tissues were observed in b-FGF, hDPC, and hDPC/b-FGF groups as compared with the control group at days 7 and 14. Our results showed that the hDPC/b-FGF group significantly promotes wound healing compared with other groups. This study implies that deciduous teeth that are currently considered as medical spare parts might offer a unique stem cell resource for potential of new cell therapies for wound healing in combination with b-FGF.

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03/07/2011 - Biological approaches toward dental pulp regeneration by tissue engineering.

J Tissue Eng Regen Med. 2011 Apr;5(4):e1-e16. doi: 10.1002/term.369. Epub 2010 Dec 30.

Sun HH, Jin T, Yu Q, Chen FM.

Department of Operative Dentistry and Endodontics, School of Stomatology, Fourth Military Medical University, Xi'an 710032, Shaanxi, People's Republic of China.

Abstract

Root canal therapy has been the predominant approach in endodontic treatment, wherein the entire pulp is cleaned out and replaced with a gutta-percha filling. However, living pulp is critical for the maintenance of tooth homeostasis and essential for tooth longevity. An ideal form of therapy, therefore, might consist of regenerative approaches in which diseased/necrotic pulp tissues are removed and replaced with regenerated pulp tissues to revitalize the teeth. Dental pulp regeneration presents one of the most challenging issues in regenerative dentistry due to the poor intrinsic ability of pulp tissues for self-healing and regrowth. With the advent of modern tissue engineering and the discovery of dental stem cells, biological therapies have paved the way to utilize stem cells, delivered or internally recruited, to generate dental pulp tissues, where growth factors and a series of dentine extracellular matrix molecules are key mediators that regulate the complex cascade of regeneration events to be faithfully fulfilled.
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02/08/2011 - Stem Cell tissue and organ engineering breakthrough announced

by Wynand van der Merwe

Lead researchers Jennifer L. West, PhD of  Rice University and Mary Dickenson, PhD of Baylor College of Medicine have developed a method to grow capillaries and blood vessels – a key element in growing tissue and organs for transplantation.  This breakthrough will advance stem cell based regeneration of tissue and organs by enabling researchers and doctors to grow thicker and more complex cellular structures.

The researchers made use of PEG (Polyethylene Glycerol), which is a non-toxic plastic, to form a base for cells to grow and then form blood vessels. Not only can they grow cells, but they can control the growth and movement of cells with the help of a process called “Two-Photon Lithography”.

“Two-Photon Lithography” is an ultra sensitive way of using light to control the movement and growth of cells which enabled the researchers to direct the growth of the cells in predetermined patterns, which for example could be the pattern of  the blood supply in a kidney.  Read more

In an earlier but related study, researchers at MIT found a way to induce cells to form tube like structures which can be used as blood vessels. EPC (Endothelial Progenitor cells) are grown on a patterned surface, that guide these cells to grow into a specific shape or size the scientists want it to grow in. According to Christopher Bettinger, PhD, this then takes the guess work out of what they are actually growing.  Read more

Success is already reported with the integration of these newly formed blood vessels within animal tissue. If a normal blood flow in these grown capillaries is established in human tissue, it could be transplanted into human organs such as the kidneys, liver, heart or any other tissue that requires vascularization.

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01/31/2011 - Stem Cells taking joint repair from bionic to biological

By Doctor Dharmini Pathmanathan, DMD, PhD

The metal and plastic parts used in 581,000 knee replacement procedures performed per year may soon take up permanent residence in medical museums. Researchers, including Dr. Jeremy Mao, Director of the Tissue Engineering and Regenerative Medicine Laboratory at Columbia University and also Chief Scientific Advisor to StemSave, are leading the way to the virtual extinction of mechanical parts constructed for joint replacements and instead are focusing on biological counterparts constructed from the patient’s own stem cells.  According to Dr. James Cook, Professor at the University of Missouri, the biological products would last longer, be more flexible and give the patient a better quality of life.” Essentially the goal is to use autologous (the patient’s own stem cells) to generate cartilage for joint replacements.  Once cartilage is injured, it is very difficult to repair and its structure, which is critical to its supporting weight, is hard to mimic, according to Fei Wang, director of the Musculoskeletal Tissue Engineering and Regenerative Medicine Program at the National Institute of Arthritis and Musculoskeletal and Skin Diseases in Bethesda, Md. Given the complexity of surgical cartilage-repair, Drs. Mao and Cook’s collaborative landmark study, recently published in The Lancet, in which the entire articular surface of a synovial joint was regenerated provides a viable option for cartilage repair. This kind of biological therapy would be life changing for those nearly 27 million people in the United States that suffer from osteoarthritis and to the significant percentage of those that end up with conventional joint replacement surgery. For Dr. Cook, observing the debilitating effects of osteoarthritis came at an early age watching his grandfather suffer from painful arthritic joints.  Even after the knee replacement surgery, his grandfather eventually was resigned to a wheelchair. Clearly the drive to find a biological alternative to the conventional metal and plastic parts used in joint replacements has been a personal mission for Dr. Cook.  As research on stem cells and their role in regenerative medicine progresses, evident in advancements noted in work including those of Drs. Mao and Cook, we are getting a glimpse of the future of modern medicine as it turns from bionic to patient-specific biological therapy.

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01/24/2011 - Dental application potential of mesenchymal stromal cells and embryonic stem cells.

Chin J Dent Res. 2010;13(2):95-103.

Liu H, Cao T.

Stem Cell Laboratory, Faculty of Dentistry, National University of Singapore, Singapore.

Abstract

In the past decade, research on the potential applications of stem cells in dentistry has made great progress. There are at least five different types of multipotent mesenchymal stromal cells (MSCs) originating from exfoliated primary teeth, including dental pulp, apica papilla, periodontal ligament, and dental follicle. It has been reported that dental tissue-derived MSCs are able to generate dentine-pulp-like complexes as well as differentiate into periodontal and craniofacial progenitor cells. Similar to these dental tissue-derived MSCs, bone marrowderived MSCs are also capable of developing into ameloblasts, odontoblasts and periodontal ligament progenitor cells, as well as regenerating cementum, alveolar bone, craniofacial bone and articular condyles. Besides adult stem cells, embryonic stem cells are an alternative cell source for dental tissue regeneration, but the current data are preliminary and are based predominantly on in vitro data. In addition to these commonly reported stem cells, other progenitor cells with MSC properties are also found in salivary glands, tongue muscle, taste buds and oral mucosa, and these may play a role in recovering the function of the residing tissues. Other than these regenerative applications, many reports have demonstrated the utility of these stem cells in cytotoxicity testing, biocompatibility testing and developmental research. The present article summarises the above findings regarding the regenerative and other potential applications of both MSCs and embryonic stem cells.

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01/24/2011 - Immunomodulatory effect of canine periodontal ligament stem cells on allogenic and xenogenic peripheral blood mononuclear cells.

J Periodontal Implant Sci. 2010 Dec;40(6):265-70. Epub 2010 Dec 31.

Kim HS, Kim KH, Kim SH, Kim YS, Koo KT, Kim TI, Seol YJ, Ku Y, Rhyu IC, Chung CP, Lee YM.

Department of Periodontology and Dental Research Institute, Seoul National University School of Dentistry, Seoul, Korea.

Abstract

PURPOSE: The aim of this study was to investigate the immunomodulatory effects of canine periodontal ligament stem cells on allogenic and xenogenic immune cells in vitro.

METHODS: Mixed cell cultures consisting of canine stem cells (periodontal ligament stem cells and bone marrow stem cells) and allogenic canine/xenogenic human peripheral blood mononuclear cells (PBMCs) were established following the addition of phytohemagglutinin. The proliferation of PBMCs was evaluated using the MTS assay. The cell division of PBMCs was analyzed using the CFSE assay. The apoptosis of PBMCs was assessed using the trypan blue uptake method.

RESULTS: Periodontal ligament stem cells and bone marrow stem cells inhibited the proliferation of allogenic and xenogenic PBMCs. Both periodontal ligament stem cells and bone marrow stem cells suppressed the cell division of PBMCs despite the existence of a mitogen. No significant differences in the percentages of apoptotic PBMCs were found among the groups.

CONCLUSIONS: Canine periodontal ligament stem cells have an immunomodulatory effect on allogenic and xenogenic PBMCs. This effect is not a product of apoptosis of PBMCs but is caused by the inhibition of cell division of PBMCs.

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01/24/2011 - Advanced and prospective technologies for potential use in craniofacial tissues regeneration by stem cells and growth factors.

J Craniofac Surg. 2011 Jan;22(1):342-8.

Bulgin D, Hodzic E, Komljenovic-Blitva D.

From the Polyclinic "ME-DENT," Rovinj, Republic of Croatia.

The processes of craniofacial tissues development and regeneration are largely dependent on sequential and reciprocal interactions between mesenchymal and epithelial components. These processes involve a series of inductive and permissive interactions that result in the determination, differentiation, and organization of craniofacial tissues. Stem cells and growth factors represent a very interesting research field for craniofacial tissues regeneration. They represent a potential key component in autologous graft for craniofacial tissues regeneration. An ideal goal of oral-craniofacial dental reconstructive therapy is to establish treatment modalities that predictably restore functional tissues. One major area of focus has been that of dental materials with marked improvements in the design of materials used to restore teeth/periodontium/bone lost as a consequence of disease or disorders. Interest in these technologies continues to increase in dental application as a substitute for traditional treatments and artificial components. Recent progress in the studies of molecular basis of tooth development, adult stem cell biology, and regeneration will provide fundamental knowledge for the realization of human craniofacial tissues regeneration in the near future.

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01/24/2011 - Future dentistry: cell therapy meets tooth and periodontal repair and regeneration.

J Cell Mol Med. 2010 Dec 28.

Catón J, Bostanci N, Remboutsika E, De Bari C, Mitsiadis TA.

Clinical and Diagnostic Sciences, Dental Institute, King's College London, London SE1 9RT, United Kingdom Institute of Oral Biology, ZZMK, Faculty of Medicine, University of Zurich, 8032 Zurich, Switzerland Stem Cell Biology Laboratory, Institute of Molecular Biology and Genetics "Alexander Fleming", Vari 16672, Greece Division of Applied Medicine, School of Medicine & Dentistry, Institute of Medical Sciences, University of Aberdeen, Aberdeen AB25 2ZD, United Kingdom Departamento de Anatomía y Embriología Humana I, Facultad de Medicina, Universidad Complutense de Madrid, 28040 Madrid, Spain.

Cell-based tissue repair of the tooth and -tooth-supporting- periodontal ligament is a new attractive approach that complements traditional restorative or surgical techniques for replacement of injured or pathologically damaged tissues. In such therapeutic approaches, stem cells and/or progenitor cells are manipulated in vitro and administered to patients as living and dynamic biological agents. In this review we discuss the clonogenic potential of human dental and periodontal tissues such as the dental pulp and the periodontal ligament and their potential for tooth and periodontal repair and/or regeneration. We propose novel therapeutic approaches using stem cells or progenitor cells, which are targeted to regenerate the lost dental or periodontal tissue.

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10/12/2010 - Transplantation of neuronal cells induced from human mesenchymal stem cells improves neurological functions after stroke without cell fusion.

J Neurosci Res. 2010 Oct 8.

Xu H, Miki K, Ishibashi S, Inoue J, Sun L, Endo S, Sekiya I, Muneta T, Inazawa J, Dezawa M, Mizusawa H.

Department of Neurology and Neurological Science, Graduate School of Medicine, Tokyo Medical and Dental University, Tokyo, Japan.

The options for treating stroke are limited, but stem cells hold promise as a therapy because of their multipotency. Neuronal cells derived from mesenchymal stem cells (MSC) were reported to have more therapeutic effect than MSCs. For elucidating the therapeutic mechanism of neuronal cells, here we generated a model of focal cerebral infarction by performing left common carotid artery occlusion in adult gerbils. We transfected human trabecular bone-derived MSCs (hMSCs) with the Notch intracellular domain to induce their differentiation into neuronal cells (hN-MSCs). These cells were stereotaxically transplanted into the local ischemic hemisphere 4 days after the occlusion. Behavioral analyses were conducted 28 days after transplantation, and then fluorescence in situ hybridization (FISH) and a histological evaluation were performed. Histologically, transplanted cells were distributed around the periinfarct region, and approximately 8.5% and 4.2% of hN-MSCs and hMSCs survived, respectively; 53.2% ± 9.6% of hN-MSCs were microtubule-associated protein 2(+) (MAP-2(+)) and extended neurites, whereas only 0.9% ± 0.3% of hMSCs were MAP-2(+). In FISH, human nucleus-specific signals were detected in both hN-MSCs and hMSCs grafted brains, but no transplanted cell had a merged gerbil-specific nuclear signals. hN-MSC-transplanted animals showed significantly better recovery than animals given control vehicle in the T-maze, bilateral asymmetry, and open field tests. These findings suggested that hN-MSCs have greater therapeutic potential than hMSCs for stroke and that cell fusion does not primarily contribute to the therapeutic mechanism of MSC transplantation. © 2010 Wiley-Liss, Inc.

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10/12/2010 - Amniotic fluid-derived MSCs lead to bone differentiation when co-cultured with dental pulp stem cells.
Tissue Eng Part A. 2010 Oct 5

De Rosa A, Tirino V, Paino F, Tartaglione A, Mitsiadis T, Feki A, D'Aquino R, Laino L, Colacurci N, Papaccio G.

Seconda Universit&#x00E0; degli Studi di Napoli, Dipartimento di Discipline Odontostomatologiche, Ortodontiche e Chirurgiche, Napoli, Italy; alfredo.derosa@unina2.it.

Abstract

Mesenchymal stem cells (MSCs) are present in many tissues of the human body, including amniotic fluid (AF) and dental pulp (DP). Stem cells of both AF and DP give rise to a variety of differentiated cells. In our experience, dental pulp stem cells (DPSCs) display a high capacity to produce bone. Therefore, our aim was to investigate if AF-derived stem cells (AFSCs) were able to undergo bone differentiation in presence of DPSCs. AFSCs were seeded under three different conditions: i) co-cultured with DPSCs previously differentiated into osteoblasts; ii) cultured in conditioned medium of osteoblast-differentiated DPSCs; iii) cultured in osteogenic medium supplemented with VEGF and BMP-2. Results showed that AFSCs were positive for mesenchymal markers, and expressed high levels of Tra1-60, Tra1-80, BMPR1, BMPR2 and BMP-2. In contrast, AFSCs were negative for epithelial and haematopoietic/endothelial markers. When AFSCs were co-cultured with DPSCs-derived-osteoblasts, they differentiated into osteoblasts. A similar effect was observed when AFSCs were cultured in presence of a conditioned medium originated from DPSCs. We found that osteoblasts derived from DPSCs released large amounts of BMP-2 and VEGF into the culture medium and that those morphogens significantly upregulate RUNX-2 gene, stimulating osteogenesis. This study highlights the mechanisms of osteogenesis and strongly suggests that the combination of AFSCs with DPSCs may provide a rich source of soluble proteins useful for bone engineering purposes.

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10/12/2010 - Gingival fibroblasts as a promising source of induced pluripotent stem cells.

PLoS One. 2010 Sep 14;5(9):e12743.

Egusa H, Okita K, Kayashima H, Yu G, Fukuyasu S, Saeki M, Matsumoto T, Yamanaka S, Yatani H.

Department of Fixed Prosthodontics, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan. egu@dent.osaka-u.ac.jp

Abstract

BACKGROUND: Induced pluripotent stem (iPS) cells efficiently generated from accessible tissues have the potential for clinical applications. Oral gingiva, which is often resected during general dental treatments and treated as biomedical waste, is an easily obtainable tissue, and cells can be isolated from patients with minimal discomfort.

METHODOLOGY/PRINCIPAL FINDINGS: We herein demonstrate iPS cell generation from adult wild-type mouse gingival fibroblasts (GFs) via introduction of four factors (Oct3/4, Sox2, Klf4 and c-Myc; GF-iPS-4F cells) or three factors (the same as GF-iPS-4F cells, but without the c-Myc oncogene; GF-iPS-3F cells) without drug selection. iPS cells were also generated from primary human gingival fibroblasts via four-factor transduction. These cells exhibited the morphology and growth properties of embryonic stem (ES) cells and expressed ES cell marker genes, with a decreased CpG methylation ratio in promoter regions of Nanog and Oct3/4. Additionally, teratoma formation assays showed ES cell-like derivation of cells and tissues representative of all three germ layers. In comparison to mouse GF-iPS-4F cells, GF-iPS-3F cells showed consistently more ES cell-like characteristics in terms of DNA methylation status and gene expression, although the reprogramming process was substantially delayed and the overall efficiency was also reduced. When transplanted into blastocysts, GF-iPS-3F cells gave rise to chimeras and contributed to the development of the germline. Notably, the four-factor reprogramming efficiency of mouse GFs was more than 7-fold higher than that of fibroblasts from tail-tips, possibly because of their high proliferative capacity.

CONCLUSIONS/SIGNIFICANCE: These results suggest that GFs from the easily obtainable gingival tissues can be readily reprogrammed into iPS cells, thus making them a promising cell source for investigating the basis of cellular reprogramming and pluripotency for future clinical applications. In addition, high-quality iPS cells were generated from mouse GFs without Myc transduction or a specific system for reprogrammed cell selection.

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10/08/2010 - Utility of PDL progenitors for in vivo tissue regeneration: a report of 3 cases.

Oral Dis. 2010 Jan;16(1):20-8.

Feng F, Akiyama K, Liu Y, Yamaza T, Wang TM, Chen JH, Wang BB, Huang GT, Wang S, Shi S.

Stem Bio Tek Corporation, Taipei, Taiwan.

Abstract

OBJECTIVE: Periodontal disease is an inflammatory disorder with widespread morbidities involving both oral and systemic health. The primary goal of periodontal treatment is the regeneration of the lost or diseased periodontium. In this study, we retrospectively examined feasibility and safety of reconstructing the periodontal intrabony defects with autologous periodontal ligament progenitor (PDLP) implantation in three patients.

MATERIALS AND METHODS: In this retrospective pilot study, we treated 16 teeth with at least one deep intrabony defect of probing depth (PD) > OR = 6 mm with PDLP transplantation and evaluated clinical outcome measures in terms of probing depth, gingival recession and attachment gain for a duration of 32-72 months. Furthermore, we compare PDLPs with standard PDL stem cells (PDLSCs) and confirmed that PDLPs possessed progenitor characters.

RESULTS: Clinical examination indicated that transplantationof PDLPs may provide therapeutic benefit for the periodontal defects. All treated patients showed no adverse effects during the entire course of follow up. We also found that PDLPs were analogous to PDLSCs in terms of high proliferation, expression of mesenchymal surface molecules, multipotent differentiation, and in vivo tissue regain. However, PDLPs failed to express scleraxis, a marker of tendon, as seen in PDLSCs.

CONCLUSIONS: This study demonstrated clinical and experimental evidences supporting a potential efficacy and safety of utilizing autologous PDL cells in the treatment of human periodontitis.

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09/02/2010 - Stem Cells Found to Aid Spinal Cord Injury Recovery

by Gregory Chotkowski, DMD

A team of researchers at Third Military Medical University in China announced earlier this month that they found transplanted stem cells helpful in the recovery of several spinal cord injuries.

The trial, conducted with rats that had sustained spinal cord damage, found that mesenchymal stem cells – which can differentiate into a variety of different tissues – facilitated repair of damaged nervous system tissue.

This line of research holds promise because the human nervous system – similar in certain ways to that of the trial animals’ – has limited capacity for regeneration, leaving spinal cord injury patients with difficult challenges to overcome. Spine trauma often leads to permanent partial or total paralysis, and sometimes death; 200,000 Americans live with its day-to-day effects.

In a related study, researchers at the University of Adelaide in Australia reported last year in trials involving birds that stem cells obtained from adult teeth, which can be harvested during wisdom tooth extraction and other routine procedures, can induce neuroplasticity within a nervous system.

This is an encouraging step towards devising methods of regrowing and repairing parts of the human nervous system that medicine has previously been unable to heal.

SOURCES

Functional recovery in acute traumatic spinal cord injury after transplantation of human umbilical cord mesenchymal stem cells”, Hu, Sheng-Li et al

“Adult Human Dental Pulp Stem Cells Differentiate Toward Functionally Active Neurons Under Appropriate Environmental Cues”, Agnes, Arthur et al

“Implanted Adult Human Dental Pulp Stem Cells Induce Endogenous Axon Guidance”, Agniezska, Arthur et al

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08/23/2010 - Breakthrough in Growing Stem Cells Outside the Body

By Gregory Chotkowski, DMD

Researchers at the Massachusetts Institute of Technology announced this week that they have created a new synthetic substance that will overcome challenges in culturing, or growing, stem cells. What is this  new synthetic substance?

As we have seen time and time again, adult human stem cells hold enormous promise for medicine, offering medicine the possibility to cure a vast number of diseases and grow new organs on demand.

The first challenge – securing a source of personalized stem cells to be used – is being tackled in a variety of ways, including the cryogenic banking of dental stem cells. Dental stem cells are found within commonly-extracted teeth, such as wisdom teeth, and can be preserved indefinitely.

The second challenge – which might more accurately be described as a host of inter-related engineering problems – is the growth and manipulation of stem cells outside of the body. Their enormous power to multiply, divide, and differentiate into virtually any tissue found in the human body is affected by a complex set of environmental, genetic and chemical factors that medical science is attempting to decode and learn to control.

The key to further advances in these decoding efforts is the ability to successfully grow substantial quantities of stem cells in an artificial environment outside of the human body, or tissue engineering. “For therapeutics, you need millions and millions of cells,” says Krishanu Saha, one of the researchers. “If we can make it easier for the cells to divide and grow, that will really help to get the number of cells you need to do all of the disease studies that people are excited about.”

The materials these artificial environments are currently made of – often “a plastic dish coated with a layer of gelatin and then a layer of mouse cells or proteins” – are “notoriously inefficient”, says Saha. A further challenge is that the rodent cells often lead to problems with rejection when the finished products of the stem cell culture are transplanted into human patients.

The MIT researchers, by adjusting various chemical and physical properties, were able to hit upon a configuration that enabled ever-increasing numbers of cells – in the millions – to continue growing and dividing for up to three months.

This is an important step forward towards the easy production of new personalized organs, in a matter of just weeks, outside of the human body – a vision that may become a reality in just decades, if not years.

SOURCES
http://web.mit.edu/newsoffice/2010/stem-cells-0823.html

"Combinatorial development of biomaterials for clonal growth of human pluripotent
stem cells" by Mei, Saha, Bogatyrev, Yang, Hook, Kalcioglu, Cho, Mitalipova, Pyzocha, Rojas, Van Vliet, Davies, Alexander, Langer, Jaenisch, Anderson. Nature Materials, 22 August, 2010.

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08/16/2010 - New Stem Cell Therapies to Repair Hearts

By Gregory Chotkowski, DMD

Heart disease is the number one cause of death and disability in the United States, killing nearly 700,000 Americans every year and the possibility of using stem cells to reverse its ravages and easily repair hearts is coming ever-closer to reality. What is Heart disease?

Stem cells can be programmed to multiply into different types of human tissue, including those that comprise the human heart. Some of the challenges in growing new organs, however, are their fantastically complex shapes, which are difficult to create outside of the body without some sort of pre-existing structure.

This is where the concept of scaffolding comes in. Cells can be introduced into a biologically compatible structure, made of degradable material and shaped like part of an organ. As the cells multiply, they assume the shape of the underlying surface, which gradually degrades, eventually leaving functional tissue which can be implanted into an organism.

It is in this area of bioengineering that a new study published this week. Researchers at the Center for Cardiovascular Biology at the University of Washington demonstrated a new type of scaffold around which heart tissue can be successfully grown. Built from a flexible polymer with interconnected channels and pores, it allows cells growing on it to receive nutrients.

Tissue grown on such a scaffold might one day be implanted into damaged hearts – perhaps after a heart attack – accelerating healing and helping the body repair itself. To make this a reality, a source of appropriate stem cells would be needed.

The requisite kind of stem cells are mesenchymal cells, which can differentiate into bone, cartilage, fat and other types of tissue. In another study published in 2008, researchers at the Prince Felipe Research Center in Valencia, Spain found that such cells harvested from dental pulp – the material found within human teeth – can aid in recovery from heart attacks.

In this study, researchers harvested stem cells from healthy teenagers who were having their wisdom teeth removed, and injected them into the hearts of rats that had suffered heart attacks. The animals showed substantial improvement in heart function and new blood vessel growth, making the study a success and opening the door to further research and the possibility, someday, of human trials.


SOURCES
http://uwnews.org/article.asp?articleID=59669
http://www.cdc.gov/features/heartmonth/
http://www.pnas.org/content/early/2010/08/02/1006442107.abstract
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08/09/2010 - Patients' own stem cells used to generate replacement windpipes to treat cancer.

By Gregory Chotkowski, DMD

Researchers at the University of Barcelona announced that they have successfully treated two patients, 19- and 31-year-old women, who were afflicted with cancer of the trachea. This kind of cancer – the cause of which is unknown – can cause intense pain and interfere with breathing and swallowing.

Doctors used the patients’ own stem cells to grow tracheas, a process which starts with a scaffolding-like tube, for this doctors harvested a trachea from a donor and treated this with detergents to remove all cells that could lead to rejection The trachea now devoid of cellular material was coated with the patient’s own stem cells harvested from bone marrow and the nasal cavity. The newly constructed windpipes were then implanted.

Dr. Paolo Macchiarini, the lead surgeon, explained that two kinds of stem cells were harvested from the patients. Each of these was used to grow tissue to replace the different lining and parts of the windpipe.. Rejection and scarcity of donors – major issues typically associated with transplants – were not an issue here, because the new tissue was newly-grown, and biologically identical to the patients’ own.

While the treatment is in the early clinical developmental stage, the success of the  treatment offers the profound promise of more widespread application in the near future.. This is a very hopeful development because the only treatments currently available for this debilitating type of cancer are chemotherapy and replacement with mechanical devices, both of which have considerable complications and have not been particularly effective.

The patients were released in just several weeks and the operation was deemed a success.  One patient was able to speak just hours after the operations.  Dr. Macchiarini, who participated in a similar trial two years ago, explained that these methods using an individual’s own stem cells could be made to apply to other organs in the future as well: "I'm thinking about the larynx or surgeries involving lungs," he said.

SOURCES
http://abcnews.go.com/Health/Health/
successful-stem-cell-trachea-transplant/story?id=11308383


http://www.macmillan.org.uk/Cancerinformation/Cancertypes/
Tracheawindpipe/Trachealcancer.aspx


http://www.google.com/hostednews/ap/
article/ALeqM5iviB9OISC7d28NW-9m-ONoLHjf3wD9H9F2LO0

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08/03/2010 - Advances in Growing New Body Parts
By Gregory Chotkowski DMD

The repair or replacement of damaged or failing organs and tissue via Regenerative Medicine is advancing by leaps and bounds, this is explored and clearly supported in a recent 60 Minutes segment.

Morley Safer of CBS News recently interviewed Dr. Anthony Atala of the Wake Forest Institute for Regenerative Medicine in North Carolina and Dr. Steven Badylak of McGowan Institute for Regenerative Medicine in Pittsburgh.

The teams in North Carolina are working to produce 22 different tissues and organs from stem cells. Three-dimensional molds are coated with successive layers of cells, which continue to grow even as the mold degrades.

One of the most stunning successes of this new field of medicine was a trial, ten years ago, in which children with failing bladders had new organs grown for them outside of their bodies and surgically implanted. They continue to enjoy normal lives to this day.

The approach taken by the Pittsburgh group is a bit different: a researched explained that “If we could make the body or at least the part of the body that's missing or injured think that it's an early fetus again,” a number of new cures could be made available.

The key to regenerative medicine is understanding how to manipulate stem cells into developing into the appropriate parts of the body. Many stem cells can be made to grow into nearly any limb or organ; the trick is to understand precisely what sort of environment is necessary for each tissue to develop.

According to Dr. Steven Wolf, chief of clinical trials at the U.S. Army's Institute for Surgical Research, the early success – including ears, esophageal lining, a hand transplant, leg wounds, rat livers, and bladders – “opens a lot of doors”.

SOURCES

http://www.cbsnews.com/stories/2009/12/11/60minutes/main5968057.shtml
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07/21/2010 - Human Lung Transplants May Become a Reality with Stem Cells

By Gregory Chotkowski, DMD

 

In an encouraging development for those suffering from lung damage or related disorders, researchers at Yale University have opened the door to a potential breakthrough in respiratory medicine by demonstrating the possibility of regenerating bio-engineered lungs.

 

These results are particularly hopeful because lung disease – the third-most-common cause of death in the United States, according to the National Institutes of Health – accounts for over 30,000 deaths each month. Human lungs are critical to survival and can only repair themselves at a very low level, falling victim to cancer, infection, and other disorders.

 

The only treatment currently available is a lung transplant, a costly procedure with 10-year survival rates under 20% and a desperate shortage of available organs. Furthermore, as with many transplants, there is the possibility of rejection, a process wherein an organism’s immune system mistakenly attacks a transplanted organ.

 

In the Yale study – conducted with rats – the researchers removed much of the tissue from donor lungs, to stave off the possibility of rejection. The result was a natural lung “scaffold”, elegantly saving bioengineers the difficult task of constructing the framework for lungs from scratch – a task made nearly-impossible by their complex shape and innumerable blood vessels.

 

Next, scientists used newborn lung cells – which, in the case of possible future human trials, may be derived from stem cells – to regrow healthy tissue over the scaffold. This one-week process produced fully-formed lungs, which were mechanically tested and then transplanted into animals.

 

The results were heartening: the regenerated lungs were implanted successfully and functioned efficiently for a short time. However, long-term success with regenerated lungs depends on the ability to more effectively grow appropriate tissue over the “scaffolding”.

 

To accomplish this, bioengineers need an appropriate source of a particular type of stem cells – those that they can cause to grow into different kinds of tissue by activating a particular combination of genes.

 

In a potentially relevant study the same month, a team of researchers at Gifu University in Japan demonstrated a promising, new potential source of the requisite cells. They worked with dental pulp cells – found inside the tooth, and typically discarded after common procedures such as root canals and wisdom tooth extractions.

 

By activating a specific set of genes in these dental cells, the researchers were able to reprogram them into pluripotent stem cells, or iPS – cells otherwise typically accessible only at or before birth, and valuable for their ability to form nearly any type of human tissue. These stems cells, when derived from teeth, are relatively easy to isolate and handle, making them a potentially indispensable future engine of personal regenerative medicine.

 

SOURCES

http://www.sciencemag.org/cgi/content/abstract/science.1189345

http://jdr.sagepub.com/content/early/2010/06/11/0022034510366846

http://www.nlm.nih.gov/medlineplus/lungdiseases.html
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07/21/2010 - Blindness Reversed With Patients’ Own Stem Cells

By Gregory Chotkowski, DMD

 

In a breakthrough study published this month in the New England Journal of Medicine, a research team in Italy used stem cell therapy to restore sight to more than three-quarters of blind and vision-impaired patients.

 

Many of the patients in the study had been blinded by chemical accidents – of which there are nearly 3,000 each year in the United States – or infections, leaving them with damaged corneas. The cornea is the transparent front part of the eye, covering the pupil.

 

In a healthy eye, the cells of the cornea are constantly dying and being renewed by adult stem cells. In these patients, due to the injuries they sustained, the part of the eye that is home to these stem cells is damaged, and the cornea becomes scarred and cloudy, causing blindness.

 

The older remedy for this, receiving a cornea transplant, is often problematic because of rejection, wherein the immune system mistakenly attacks the transplanted organ, leading to potentially serious complications.

 

In this new treatment, doctors took a tiny patch of stem cells from each patient’s healthier eye, cultivated it in a special chemical brew – actually growing new cells – and grafted the resulting tissue into the affected areas of both eyes.

 

The results of this new form of stem cell therapy were nothing short of incredible: blindness was reversed in 78% of patients, with an additional 13% showing marked improvement. Many had previously undergone multiple unsuccessful operations, and some of the injuries were decades old.

 

The improvements persisted, even after follow-ups an average of three years after the procedure. Rejection was not an issue, as the patient’s own cells were used. This is the most promising result yet in a series of findings that give hope to those with vision impairments, and is further evidence of the power of stem cells.

 

Unfortunately, the strength of this kind of therapy– using the patient’s own cells – is also a weakness, because doctors need to harvest a small number of healthy cells to perform the treatment; in cases of severe enough damage to both eyes, the therapy is “not applicable”, according to the research, because there is no source of the patient’s own stem cells to begin with.

 

There are indications, however, that even this limitation may be overcome in the near future –

by using stem cells from human teeth. Earlier this year, a research team in Brazil showed, in trials conducted with rabbits, that it is not only possible to reconstruct corneas in this way, but surprisingly effective.

 

This is thought to be because – as published in a 2008 paper by the same team – stem cells in human teeth share important characteristics with those in eyes, including several key genetic markers and the ability to self-renew. This opens the door to human trials, given an appropriate source of dental stem cells.
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06/18/2010 - Stem cell therapy - Hype or hope? A review.

J Conserv Dent. 2009 Oct;12(4):131-8.

Nadig RR.

Department of Conservative Dentistry and Endodontics, Dayananda Sagar College of Dental Sciences, Bangalore, Karnataka, India.

Abstract

While the regeneration of a lost tissue is known to mankind for several years, it is only in the recent past that research on regenerative medicine/dentistry has gained momentum and eluded the dramatic yet scientific advancements in the field of molecular biology. The growing understanding of biological concepts in the regeneration of oral/dental tissues coupled with experiments on stem cells is likely to result in a paradigm shift in the therapeutic armamentarium of dental and oral diseases culminating in an intense search for "biological solutions to biological problems." Stem cells have been successfully isolated from variety of human tissues including orofacial tissues. Initial evidence from pioneering studies has documented the likely breakthrough that stem cells offer for various life-threatening diseases that have so far defeated modern medical care. The evidence gathered so far has propelled many elegant studies exploring the role of stem cells and their manifold dental applications. This review takes you on a sojourn of the origin of stem cells, their properties, characteristics, current research, and their potential applications. It also focuses on the various challenges and barriers that we have to surmount before translating laboratory results to successful clinical applications heralding the dawn of regenerative dentistry.

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06/18/2010 - A New Method for Alveolar Bone Repair Using Extracted Teeth for the Graft Material.

J Periodontol. 2010 May 17.

Nampo T, Watahiki J, Enomoto A, Taguchi T, Ono M, Nakano H, Yamamoto G, Irie T, Tachikawa T, Maki K.

Department of Orthodontics, School of Dentistry, Showa University.2-1-1 Kitasenzoku, Ohta-ku, Tokyo 145-8515, Japan.

Abstract

Background: Currently, in the clinical field of jawbone formation, the use of autogenous bone as the graft material is the gold standard. However, there are some problems with this technique, such as risk of infection on the donor side, the limited amount of available bone mass, and marked resorption of the grafted bone. We investigated the potential for using teeth as a bone graft material for jawbone formation because the dental pulp contains stem cells, including undifferentiated neural crest derived cells. Methods: Alveolar bone defects were created in Wistar rats, and the defects were filled with either tooth or iliac bone graft material, or left as controls. The potential for using teeth as a bone graft material for jawbone formation was measured using real-time polymerase chain reaction, micro-computed tomography (mu-CT), and histological analysis. Results: Polymerase chain reaction revealed that the expressions of P75, P0, Nestin, and Musashi-1 were significantly higher in teeth than in mandibular bone and iliac bone grafts. Hematoxylin and eosin staining and mu-CT showed that at 8 weeks, tooth graft material produced a similar amount of new bone compared with iliac bone graft material. Osteopontin was expressed in both the tooth and iliac bone graft material at 6 and 8 weeks after surgery. Dentin sialoprotein was expressed in the tooth graft material in the new bone at 6 weeks only. Conclusions: These results indicate that teeth may be an alternative material to autogenous bone for treating alveolar bone defects by grafting.

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06/18/2010 - Human mesenchymal stem cell-derived Schwann cell-like cells exhibit neurotrophic effects, via distinct growth factor production, in a model of spinal cord injury.

Glia. 2010 Jul;58(9):1118-32.

Park HW, Lim MJ, Jung H, Lee SP, Paik KS, Chang MS.

Department of Oral Anatomy, Dental Research Institute and School of Dentistry, Seoul National University, 28 Yeongeon-Dong, Jongno-Gu, Seoul 110-749, Republic of Korea.

Abstract

Human bone marrow-derived mesenchymal stem cells (hMSCs) are considered a desirable cell source for autologous cell transplantation therapy to treat nervous system injury due to their ability to differentiate into specific cell types and render the tissue microenvironment more favorable for tissue repair by secreting various growth factors. To potentiate their possible trophic effect, hMSCs were induced without genetic modification to adopt characteristics of Schwann cells (SCs), which provide trophic support for regenerating axons. The induced hMSCs (shMSCs) adopted a SC-like morphology and expressed SC-specific proteins including the p75 neurotrophin receptor, which correlated with cell-cycle exit. In addition, shMSCs secreted higher amounts of several growth factors, such as hepatocyte growth factor (HGF) and vascular endothelial growth factor (VEGF) when compared with uninduced hMSCs. Coculture of shMSCs with Neuro2A cells significantly increased neurite outgrowth and cell proliferation but decreased cell death. Transplantation of shMSCs in an ex vivo model of spinal cord injury dramatically enhanced axonal outgrowth, which was mediated by HGF and VEGF secretion and also decreased cell death. These results demonstrate that shMSCs could serve as an endogenous source of neurotrophic growth factors to facilitate axonal regeneration while at the same time protecting the resident cells at the site of tissue injury. We propose that these induced hMSCs without genetic modification are useful for autologous cell therapy to treat nervous system injury. Copyright 2010 Wiley-Liss, Inc.

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06/18/2010 - Quantitative, structural, and image-based mechanical analysis of nonunion fracture repaired by genetically engineered mesenchymal stem cells.

J Biomech. 2010 May 13.

Kallai I, van Lenthe GH, Ruffoni D, Zilberman Y, Müller R, Pelled G, Gazit D.

Skeletal Biotech Laboratory, The Hebrew University - Hadassah Faculty of Dental Medicine, PO Box 12272, Ein Kerem, Jerusalem 91120, Israel.

Abstract

Stem cell-mediated gene therapy for fracture repair, utilizes genetically engineered mesenchymal stem cells (MSCs) for the induction of bone growth and is considered a promising approach in skeletal tissue regeneration. Previous studies have shown that murine nonunion fractures can be repaired by implanting MSCs over-expressing recombinant human bone morphogenetic protein-2 (rhBMP-2). Nanoindentation studies of bone tissue induced by MSCs in a radius fracture site indicated similar elastic modulus compared to intact murine bone, eight weeks post-treatment. In the present study we sought to investigate temporal changes in microarchitecture and biomechanical properties of repaired murine radius bones, following the implantation of MSCs. High-resolution micro-computed tomography (micro-CT) was performed 10 and 35 weeks post MSC implantation, followed by micro-finite element (micro-FE) analysis. The results have shown that the regenerated bone tissue remodels over time, as indicated by a significant decrease in bone volume, total volume, and connectivity density combined with an increase in mineral density. In addition, the axial stiffness of limbs repaired with MSCs was 2-1.5 times higher compared to the contralateral intact limbs, at 10 and 35 weeks post-treatment. These results could be attributed to the fusion that occurred in between the ulna and radius bones. In conclusion, although MSCs induce bone formation, which exceeds the fracture site, significant remodeling of the repair callus occurs over time. In addition, limbs treated with an MSC graft demonstrated superior biomechanical properties, which could indicate the clinical benefit of future MSC application in nonunion fracture repair. Copyright © 2010 Elsevier Ltd. All rights reserved.

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05/11/2010 - Johns Hopkins School of Medicine enters collaboration with New York Stem Cell Foundation
The Johns Hopkins University School of Medicine and the New York Stem Cell Foundation (NYSCF) are establishing a collaborative program to advance the development and use of stem cells in therapies for a wide range of diseases, the organizations announced today. The program will train researchers to use stem cells and foster joint research projects. "We are exceptionally proud to partner with the New York Stem Cell Foundation," says Chi V. Dang, M.D., Ph.D., executive director of the Johns Hopkins Institute for Cell Engineering and vice dean for research at the Johns Hopkins University School of Medicine. "This is a great opportunity to cross fertilize two rich research programs and develop new and lasting efforts to further stem cell research." The joint program includes the establishment of workshops in state-of-the-art stem cell technologies for Johns Hopkins students, fellows and faculty at the NYSCF laboratories in New York City, one of the few places in the nation offering comprehensive expertise in stem cell derivation and maintenance. An inaugural three-day workshop took place in February. The collaboration also is expected to yield production of standardized and quality-controlled human pluripotent stem cell lines by the NYSCF staff for use in Parkinson's disease and other disorders. Johns Hopkins researchers will provide research samples and the NYSCF stem cell derivation team will grow more cells from them, as well as reprogram, characterize and maintain quality control of the cells. The cell lines created will be banked in the NYSCF repository and will eventually serve as a resource for other researchers. The collaboration establishes an NYSCF Fellowship Award to enable a Johns Hopkins stem cell researcher to pursue projects with researchers outside of Johns Hopkins. "This is a wonderful opportunity to work with this world-class group of researchers to use stem cells to cure the terrible diseases that affect us all," said Susan L. Solomon, CEO of the New York Stem Cell Foundation. "We look forward to a very long, active and productive relationship between our two institutions." ### On the Web: Institute for Cell Engineering: http://www.hopkins-ice.org/index.html Stem Cell Research at Johns Hopkins: http://www.hopkinsmedicine.org/stem_cell_research/ NYSCF: http://www.nyscf.org/
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03/30/2010 - Replacement Bones, Grown to Order in the Lab

Gordana Vunjak-Novakovic a professor of biomedical engineering at Columbia University and a Scientific Advisor to StemSave has solved one of many problems on the way to successful bone implants: how to grow new bones in the anatomical shape of the original.

Dr. Vunjak-Novakovic and her research team have created and nourished two small bones from scratch in their laboratory. The new bones, part of a joint at the back of the jaw, were created with human stem cells. The shape is based on digital images of undamaged bones.

Dr. Vunjak-Novakovic, Dr. Warren L. Grayson and other members of the team used digital images of the joint to guide a machine that carved a three-dimensional replica, called a scaffold, from cleansed bone material. The team turned the bare scaffold into living tissue by putting it into a chamber molded to its exact shape, and adding human cells, typically isolated from bone marrow or liposuctioned fat. A steady source of oxygen, growth hormones, sugar and other nutrients was piped into the chamber, or bioreactor, so the bone would flourish.

“The cells grow rapidly,” Dr. Vunjak-Novakovic said. “They don’t know whether they are in the body or in a culture. They only sense the signals.”

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03/14/2010 - Deciduous and permanent dental pulp mesenchymal cells acquire hepatic morphologic and functional features in vitro.

Ishkitiev N, Yaegaki K, Calenic B, Nakahara T, Ishikawa H, Mitiev V, Haapasalo M.

Department of Oral Health, Nippon Dental University, School of Life Dentistry at Tokyo, Tokyo, Japan.

INTRODUCTION: Mesenchymal stem cells display extensive proliferative capacity of multilineage differentiation. The stromal compartment of mesenchymal tissues is considered to harbor stem cells. We assessed the endodermal differentiation of mesenchymal cells from deciduous and wisdom tooth pulp. METHODS: Dental mesenchymal cells were isolated and expanded in vitro. After cell cultures had been established, cells were characterized using known stem cell markers. For hepatic differentiation the media was supplemented with hepatic growth factor, dexamethasone, Insulin-Transferrin-Selenium-X, and oncostatin. RESULTS: Both cultures showed a number of cells positive for specific hepatic markers including alpha-fetoprotein, albumin, and hepatic nuclear factor 4alpha after differentiation. Also, small clusters of cells positive for insulin-like growth factor 1 were found. The concentration of urea increased significantly in the media. Moreover, a significant amount of glycogen was found in the cells. CONCLUSION: Because the cells proved to produce specific hepatic proteins and to start functions specific for hepatocytes, such as storing glycogen and urea production, we may state that the mesenchymal cell cultures from wisdom and deciduous tooth pulp acquired morphologic and functional characteristics of hepatocytes. Copyright (c) 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

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03/13/2010 - Addition of Mesenchymal Stem Cells to the Scaffold of Platelet-Rich Plasma Is Beneficial for the Reduction of the Consolidation Period in Mandibular Distraction Osteogenesis.
J Oral Maxillofac Surg. 2010 Mar 10

Hwang YJ, Choi JY.

Full Time Lecturer, Department of Oral and Maxillofacial Surgery, Hallym University Dental Hospital, Seoul, South Korea.

PURPOSE: Platelet-rich plasma (PRP) is a wonderful scaffold to induce osteogenesis. In this study, we investigated whether the combination of mesenchymal stem cells (MSC) with PRP has advantages over PRP for the reduction of consolidation period in mandibular distraction osteogenesis. MATERIALS AND METHODS: After osteotomy, an external distraction device was fixed in both mandibles of 38 rabbits. After a 5-day latency period, a total of 6.3 mm was distracted for 6 days. PRP gel with or without MSC was injected into the distracted area on day 1 of the consolidation period. Healing tissues were analyzed histologically, radiologically, and mechanically on weeks 1, 2, 3, and 4 after consolidation. RESULTS: In week 1, the MSC/PRP group was 34%, 20%, 21%, and 32% higher than the PRP group in the result of histomorphometry, radiodensity ratio of new bone/host bone and new bone/adjacent tooth, and microhardness test, respectively. Consolidation period was reduced by 6.6 and 5.1 days at 80% and 90% new bone/host bone ratio through regression analysis, respectively. CONCLUSION: The addition of MSC in PRP scaffold significantly (P < .05) increased new bone formation, mineralization, and mechanical property compared to the PRP-only group. These results indicate that the combination therapy of MSC and PRP is more effective for reducing the consolidation period of distraction. Copyright © 2010. Published by Elsevier Inc.

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03/13/2010 - Use of Cell-Based Approaches in Maxillary Sinus Augmentation Procedures.
J Craniofac Surg. 2010 Mar 5

Park JB.

From the Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, Michigan.

The dimension of alveolar ridge is decreased by bone atrophy and pneumatization of the maxillary sinus after loss of teeth in the posterior maxilla, and sinus augmentation procedures are performed to create bone quantity and quality to ensure the placement of dental implants.Various osteoconductive materials have been used to augment the sinus floor, but these materials are cell-free and require more time for bone healing. Attempts have been made to apply a cell-based approach that uses mesenchymal stem cells combined with an osteoconductive scaffold. Adult stem cells that can be derived from various tissues including bone marrow, periosteum, and trabecular bone have been applied in sinus augmentation procedures both experimentally and clinically with successful results.In this review, the cell-based approaches in sinus augmentation procedures with various carriers will be described and the efficacy and clinical applicability will be addressed.

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01/08/2010 - Embryonic stem cell marker expression pattern in human mesenchymal stem cells derived from bone marrow, adipose tissue, heart and dermis.
Stem Cell Rev. 2009 Dec;5(4):378-86.

Riekstina U, Cakstina I, Parfejevs V, Hoogduijn M, Jankovskis G, Muiznieks I, Muceniece R, Ancans J.

Faculty of Medicine, University of Latvia, Riga LV-1001, Latvia. Una.Riekstina@lu.lv

Mesenchymal stem cells (MSCs) have been isolated from a variety of human tissues, e.g., bone marrow, adipose tissue, dermis, hair follicles, heart, liver, spleen, dental pulp. Due to their immunomodulatory and regenerative potential MSCs have shown promising results in preclinical and clinical studies for a variety of conditions, such as graft versus host disease (GvHD), Crohn's disease, osteogenesis imperfecta, cartilage damage and myocardial infarction. MSC cultures are composed of heterogeneous cell populations. Complications in defining MSC arise from the fact that different laboratories have employed different tissue sources, extraction, and cultivation methods. Although cell-surface antigens of MSCs have been extensively explored, there is no conclusive evidence that unique stem cells markers are associated with these adult cells. Therefore the aim of this study was to examine expression of embryonic stem cell markers Oct4, Nanog, SOX2, alkaline phosphatase and SSEA-4 in adult mesenchymal stem cell populations derived from bone marrow, adipose tissue, dermis and heart. Furthermore, we tested whether human mesenchymal stem cells preserve tissue-specific differences under in vitro culture conditions. We found that bone marrow MSCs express embryonic stem cell markers Oct4, Nanog, alkaline phosphatase and SSEA-4, adipose tissue and dermis MSCs express Oct4, Nanog, SOX2, alkaline phosphatase and SSEA-4, whereas heart MSCs express Oct4, Nanog, SOX2 and SSEA-4. Our results also indicate that human adult mesenchymal stem cells preserve tissue-specific differences under in vitro culture conditions during early passages, as shown by distinct germ layer and embryonic stem cell marker expression patterns. Studies are now needed to determine the functional role of embryonic stem cell markers Oct4, Nanog and SOX2 in adult human MSCs.

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11/20/2009 - Human mandible bone defect repair by the grafting of dental pulp stem/progenitor cells and collagen sponge biocomplexes.
Eur Cell Mater. 2009 Nov 12;18:75-83.

d'Aquino R, De Rosa A, Lanza V, Tirino V, Laino L, Graziano A, Desiderio V, Laino G, Papaccio G.

Department of Experimental Medicine, Section of Histology and Embryology, TERM Division, 2nd University of Naples, Naples, Italy.

In this study we used a biocomplex constructed from dental pulp stem/progenitor cells (DPCs) and a collagen sponge scaffold for oro-maxillo-facial (OMF) bone tissue repair in patients requiring extraction of their third molars. The experiments were carried out according to our Internal Ethical Committee Guidelines and written informed consent was obtained from the patients. The patients presented with bilateral bone reabsorption of the alveolar ridge distal to the second molar secondary to impaction of the third molar on the cortical alveolar lamina, producing a defect without walls, of at least 1.5 cm in height. This clinical condition does not permit spontaneous bone repair after extraction of the third molar, and eventually leads to loss also of the adjacent second molar. Maxillary third molars were extracted first for DPC isolation and expansion. The cells were then seeded onto a collagen sponge scaffold and the obtained biocomplex was used to fill in the injury site left by extraction of the mandibular third molars. Three months after autologous DPC grafting, alveolar bone of patients had optimal vertical repair and complete restoration of periodontal tissue back to the second molars, as assessed by clinical probing and X-rays. Histological observations clearly demonstrated the complete regeneration of bone at the injury site. Optimal bone regeneration was evident one year after grafting. This clinical study demonstrates that a DPC/collagen sponge biocomplex can completely restore human mandible bone defects and indicates that this cell population could be used for the repair and/or regeneration of tissues and organs.

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11/07/2009 - Mesenchymal Stem Cells Derived from Human Gingiva Are Capable of Immunomodulatory Functions and Ameliorate Inflammation-Related Tissue Destruction in Experimental Colitis.

J Immunol. 2009 Nov 18. [Epub ahead of print]

Zhang Q, Shi S, Liu Y, Uyanne J, Shi Y, Shi S, Le AD.

*Center for Craniofacial Molecular Biology, University of Southern California, School of Dentistry, Los Angeles, CA 90033.

Aside from the well-established self-renewal and multipotent differentiation properties, mesenchymal stem cells exhibit both immunomodulatory and anti-inflammatory roles in several experimental autoimmune and inflammatory diseases. In this study, we isolated a new population of stem cells from human gingiva, a tissue source easily accessible from the oral cavity, namely, gingiva-derived mesenchymal stem cells (GMSCs), which exhibited clonogenicity, self-renewal, and multipotent differentiation capacities. Most importantly, GMSCs were capable of immunomodulatory functions, specifically suppressed peripheral blood lymphocyte proliferation, induced expression of a wide panel of immunosuppressive factors including IL-10, IDO, inducible NO synthase (iNOS), and cyclooxygenase 2 (COX-2) in response to the inflammatory cytokine, IFN-gamma. Cell-based therapy using systemic infusion of GMSCs in experimental colitis significantly ameliorated both clinical and histopathological severity of the colonic inflammation, restored the injured gastrointestinal mucosal tissues, reversed diarrhea and weight loss, and suppressed the overall disease activity in mice. The therapeutic effect of GMSCs was mediated, in part, by the suppression of inflammatory infiltrates and inflammatory cytokines/mediators and the increased infiltration of regulatory T cells and the expression of anti-inflammatory cytokine IL-10 at the colonic sites. Taken together, GMSCs can function as an immunomodulatory and anti-inflammatory component of the immune system in vivo and is a promising cell source for cell-based treatment in experimental inflammatory diseases.

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10/19/2009 - Donor-matched comparison of dental pulp stem cells and bone marrow-derived mesenchymal stem cells in a rat model.
J Tissue Eng Regen Med. 2009 Oct 19

Alge DL, Zhou D, Adams LL, Wyss BK, Shadday MD, Woods EJ, Gabriel Chu TM, Goebel WS.

Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47908, USA.

Dental pulp stem cells (DPSCs) have drawn much interest for the regeneration of mineralized tissues, and several studies have compared DPSCs to bone marrow-derived mesenchymal stem cells (BMMSCs). However, conflicting results, possibly due to donor-associated variability, have been published and the regenerative potential of DPSCs is currently unclear. In the present study we have sought to address this problem using a donor-matched experimental design to robustly compare the biological properties of DPSCs and BMMSCs. All experiments were performed using cells isolated from a single adult Sprague-Dawley rat. Our results show that DPSCs and BMMSCs had similar morphologies and flow cytometry profiles, were capable of forming colonies in vitro and were capable of osteogenic, chondrogenic and adipogenic differentiation. However, quantitative comparisons revealed that DPSCs had a faster population doubling time and a higher percentage of stem/progenitor cells in the population, as determined by clonogenic assays. Furthermore, while both cell populations formed mineral in vitro, DPSCs had significantly higher alkaline phosphatase activity than BMMSCs after 3 weeks in osteogenic medium. These data show several key differences between DPSCs and BMMSCs and support the possibility of using DPSCs for mineralized tissue regeneration. Copyright (c) 2009 John Wiley & Sons, Ltd.

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10/16/2009 - The periosteum as a cellular source for functional tissue engineering.
Tissue Eng Part A. 2009 Sep;15(9):2637-42.

Arnsdorf EJ, Jones LM, Carter DR, Jacobs CR.

Bone and Joint R&D Center, VA Palo Alto Health Care System, Palo Alto, California, USA. emily.arnsdorf@gmail.com

The periosteum, a specialized fibrous tissue composed of fibroblast, osteoblast, and progenitor cells, may be an optimal cell source for tissue engineering based on its accessibility, the ability of periosteal cells to proliferate rapidly both in vivo and in vitro, and the observed differentiation potential of these cells. However, the functional use of periosteum-derived cells as a source for tissue engineering requires an understanding of the ability of such cells to elaborate matrix of different tissues. In this study, we subjected a population of adherent primary periosteum-derived cells to both adipogenic and osteogenic culture conditions. The commitment propensity of periosteal cells was contrasted with that of well-characterized phenotypically pure populations of NIH3T3 fibroblast and MC3T3-E1 osteoblast cell lines. Our results demonstrate that the heterogeneous populations of periosteal cells and NIH3T3 fibroblasts have the ability to express both osteoblast-like and adipocyte-like markers with similar potential. This raises the question of whether fibroblasts within the periosteum may, in fact, have the potential to behave like progenitor cells and play a role in the tissue's multilineage potential or whether there are true stem cells within the periosteum. Further, this study suggests that expanded periosteal cultures may be a source for tissue engineering applications without extensive enrichment or sorting by molecular markers. Thus, this study lays the groundwork for future investigations that will more deeply enumerate the cellular sources and molecular events governing periosteal cell differentiation.

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10/08/2009 - CORNEAL RECONSTRUCTION WITH TISSUE-ENGINEERED CELL SHEETS COMPOSED OF HUMAN IMMATURE DENTAL PULP STEM CELLS.
Invest Ophthalmol Vis Sci. 2009 Nov 5.

Gomes J, Monteiro BG, Melo GB, Smith RL, Silva MC, Lizier NF, Kerkis A, Cerruti H, Kerkis I.

Ophthalmology, Fed Uni of Sao Paulo, Sao Paulo, Brazil.

Purpose: To determine the outcome of the use of a tissue-engineered cell sheet composed of human undifferentiated immature dental pulp stem cells (hIDPSC) for ocular surface reconstruction in an animal model of total limbal stem cell deficiency (LSCD). Methods: LSCD was induced by the application of 0.5 M NaOH to the right eye of rabbits for 25 s (mild chemical burn, MCB) and for 45 s (severe chemical burn, SCB). After 1 month, a superficial keratectomy was performed to remove the fibrovascular pannus that covered the animals burned cornea. A tissue-engineered hIDPSC sheet was transplanted onto the corneal bed and then covered with deepithelialized human amniotic membrane (AM). In the respective control groups, the denuded cornea was covered with AM only. After 3 months, a detailed analysis of the rabbit eyes was performed with regard to clinical aspect, histology, electron microscopy and immunohistochemistry. Results: Corneal transparency of the rabbit eyes that underwent hIDPSC transplantation was improved throughout the follow-up while the control corneas developed total conjunctivalization and opacification. Rabbits from the MCB group showed clearer corneas with less neovascularization. The clinical data were confirmed by histological analysis that showed healthy uniform corneal epithelium, especially in the MCB group. The presence of hIDPSC was detected using an anti-hIDPSC antibody. The corneal tissue also showed positive immunostaining with anti-human antibodies. In the control corneas, none of these antigens was detected. Conclusions: Overall, our data showed that transplantation of a tissue-engineered hIDPSC sheet was successful for the reconstruction of corneal epithelium in an animal model of LSCD.

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10/06/2009 - Facial Reconstruction by Biosurgery: Cell Transplantation vs. Cell Homing.

Tissue Eng Part B Rev. 2009 Nov 5.

Mao J, Stosich MS, Moioli E, Lee CH, Fu S, Bastian B, Eisig S, Zemnick C, Ascherman J, Wu J, Rohde C, Ahn J.

Columbia University, Biomedical Engineering and Dental Medicine, 630 W. 168 St. - PH 7 East, New York, New York, United States, 10032, 212-305-4475; jmao@columbia.edu.

The face distinguishes one human being from another. When the face is disfigured from trauma, tumor removal, congenital anomalies or chronic diseases, the patient has a strong desire for functional and esthetic restoration. Current practice of facial reconstruction using autologous grafts, synthetic fillers and prostheses is frequently below the surgeon's and patient's expectations. Facial reconstruction has yet to take advantage of recent advances in seemingly unrelated fields of stem cell biology, chemical engineering, biomaterials and tissue engineering. "Biosurgery", a new concept that we propose, will incorporate novel principles and strategies of bioactive cues, biopolymers and/or cells to restore facial defects. Small facial defects can likely be reconstructed by cell homing and without cell transplantation. A critical advantage of cell homing is that agilely recruited endogenous cells have the potential to harness the host's innate capacity for regeneration, thus accelerating the rate of regulatory and commercialization processes for product development. Large facial defects, however, may not be restorable without cell delivery per our understanding at this time. New breakthrough in biosurgery will likely originate from integrated strategies of cell biology, cytokine biology, chemical engineering, biomaterials and tissue engineering. Regardless of cell homing or cell delivery approaches, biosurgery not only will minimize surgical trauma and repetitive procedures, but also produce long-lasting results. At the same time, caution must be exercised against the development of products that lack scientific basis or dogmatic combination of cells, biomaterials and biomolecules. Together, scientifically derived biosurgery will undoubtedly develop into new technologies that offer increasingly natural reconstruction and/or augmentation of the face.

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07/26/2009 - Histologic evaluation of a stem cell-based sinus-augmentation procedure.
J Periodontol. 2009 Apr;80(4):679-86

McAllister BS, Haghighat K, Gonshor A.

Private practice, Portland, OR, USA.

BACKGROUND: Predictability has been demonstrated for the long-term success of dental implants placed simultaneously with or after a sinus-augmentation procedure. However, the time required to obtain optimal bone formation can be from 6 to 9 months or longer with grafting materials other than autogenous bone. For this reason, there is interest in a surgical technique that does not require the harvest of autogenous bone but still results in sufficient bone formation within a relatively short time frame. METHODS: The purpose of this case series was to evaluate the bone formation following sinus-augmentation procedures using an allograft cellular bone matrix containing native mesenchymal stem cells. Biopsy and histologic evaluation were performed after approximately 4 months of healing. RESULTS: Histomorphometric analysis revealed an average vital bone content of 33% (range, 22% to 40%) and an average residual graft content of 6% (range, 3% to 7%) for the five cases reported that had an average healing period of 4.1 months (range, 3 to 4.75 months). CONCLUSION: The high percentage of vital bone content, after a relatively short healing phase, may encourage a more rapid initiation of implant placement or restoration when a cellular grafting approach is considered.

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07/26/2009 - Secondary repair of alveolar clefts using human mesenchymal stem cells.
Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2009 Aug;108(2):e1-6.

Behnia H, Khojasteh A, Soleimani M, Tehranchi A, Khoshzaban A, Keshel SH, Atashi R.

Department of Oral and Maxillofacial Surgery, Taleghani Hospital, Dental Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.

Recently tissue engineering has become available as a regenerative treatment for bone defects; however, little has been reported on the application of tissue engineering for regeneration of cleft defect tissues. Mesenchymal-derived stem cells were applied to different kinds of bone substitute and compared in different animal models, but their usage in human critical defects remained unclear. In this study we report 2 patients with unilateral alveolar cleft, treated with the composite scaffold of demineralized bone mineral and calcium sulphate (Osteoset) loaded with mesenchymal stem cells (MSCs). Computed tomograms showed 34.5% regenerated bone, extending from the cleft walls and bridging the cleft after 4 months in one case and in the other there was 25.6% presentation of bone integrity. The available data revealed the conventional bone substitute was not a suitable scaffold for the MSC-induced bone regeneration.

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07/26/2009 - Human immature dental pulp stem cells share key characteristic features with limbal stem cells.
Cell Prolif. 2009 Jul 14.

Monteiro BG, Serafim RC, Melo GB, Silva MC, Lizier NF, Maranduba CM, Smith RL, Kerkis A, Cerruti H, Gomes JA, Kerkis I.

Genetics Laboratory, Butantan Institute, São Paulo, SP, Brazil.

Abstract Objectives: Limbal stem cells (LSC) are self-renewing, highly proliferative cells in vitro, which express a set of specific markers and in vivo have the capacity to reconstruct the entire corneal epithelium in cases of ocular surface injury. Currently, LSC transplantation is a commonly used procedure in patients with either uni- or bilateral total limbal stem cells deficiency (TLSCD). Although LSC transplantation holds great promise for patients, several problems need to be overcome. In order to find an alternative source of cells that can partially substitute LSC in cornea epithelium reconstruction, we aimed at investigating whether human immature dental pulp stem cells (hIDPSC) would present similar key characteristics as LSC and whether they could be used for corneal surface reconstruction in a rabbit TLSCD model. Materials: We used hIDPSC, which co-express mesenchymal and embryonic stem cell markers and present the capacity to differentiate into derivative cells of the three germinal layers. TLSCD was induced by chemical burn in one eye of rabbits. After 30 days, the opaque tissue formed was removed by superficial keratectomy. Experimental group received undifferentiated hIDPSC, while control group only received amniotic membrane (AM). Both groups were sacrificed after 3 months. Results and conclusions: We have demonstrated, using immunohistochemistry and reverse transcription-polymerase chain reaction, that hIDPSCs express markers in common with LSC, such as ABCG2, integrin beta1, vimentin, p63, connexin 43 and cytokeratins 3/12. They were also capable of reconstructing the eye surface after induction of unilateral TLSCD in rabbits, as shown by morphological and immunohistochemical analysis using human-specific antibodies against limbal and corneal epithelium. Our data suggest that hIDPSCs share similar characteristics with LSC and might be used as a potential alternative source of cells for corneal reconstruction.

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07/26/2009 - Human fallopian tube: a new source of multipotent adult mesenchymal stem cells discarded in surgical procedures
J Transl Med. 2009 Jun 18;7:46

Jazedje T, Perin PM, Czeresnia CE, Maluf M, Halpern S, Secco M, Bueno DF, Vieira NM, Zucconi E, Zatz M.

Human Genome Research Center, Biosciences Institute, University of São Paulo, n degrees 106, Cidade Universitária São Paulo SP, CEP: 05508-090, Brazil. tatiana@ib.usp.br

BACKGROUND: The possibility of using stem cells for regenerative medicine has opened a new field of investigation. The search for sources to obtain multipotent stem cells from discarded tissues or through non-invasive procedures is of great interest. It has been shown that mesenchymal stem cells (MSCs) obtained from umbilical cords, dental pulp and adipose tissue, which are all biological discards, are able to differentiate into muscle, fat, bone and cartilage cell lineages. The aim of this study was to isolate, expand, characterize and assess the differentiation potential of MSCs from human fallopian tubes (hFTs). METHODS: Lineages of hFTs were expanded, had their karyotype analyzed, were characterized by flow cytometry and underwent in vitro adipogenic, chondrogenic, osteogenic, and myogenic differentiation. RESULTS: Here we show for the first time that hFTs, which are discarded after some gynecological procedures, are a rich additional source of MSCs, which we designated as human tube MSCs (htMSCs). CONCLUSION: Human tube MSCs can be easily isolated, expanded in vitro, present a mesenchymal profile and are able to differentiate into muscle, fat, cartilage and bone in vitro.

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03/02/2009 - Stem Cells: What will they be when they grow out?
RDH Magazine Volume 29 Issue 2  February, 2009

by Diane Brucato-Thomas, RDH, EF, BS, FAADH

Parkinson's disease is just one of many previously incurable diseases and conditions that may find a cure in stem cell regenerative therapies. Muscular dystrophy, Alzheimer's disease, osteoporosis, diabetes, cardiovascular disease, renal failure, and spinal cord injuries are a few others. Virtually any disease that occurs as a result of damaged, failing or malfunctioning tissues may potentially be cured through regenerative therapies.

Stem cells from one part of the body will be expanded (grown out) and reimplanted to replace an entirely different type of tissue. This type of transplant will totally negate the need for antirejection drugs, since the implant is made of the patient's own body cells.

Most recently, the very first engineered whole organ transplant, using a windpipe made with the patient's own stem cells, was successfully completed by surgeons in Spain. The patient was a 30-year-old woman, whose airways were damaged by tuberculosis and who needed the transplant to save her lung.

The doctors removed a trachea and bronchus from a donor patient who recently died. Using strong chemicals and enzymes, all of the cells were dissolved from the donor trachea, leaving only a fibrous tissue scaffolding made of collagen protein. This structure was used as the framework to repopulate with the woman's own cells. The doctors used two types of the woman's own cells to populate the scaffold — cells lining her own windpipe, and very immature bone marrow cells (adult stem cells), which could be encouraged to form the kind of cells that normally surround the trachea.

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02/07/2009 - Patients own stem cells used to create the world's first tissue engineered whole organ transplant

The groundbreaking technology also means for the first time tissue transplants can be carried out without the need for anti-rejection drugs. Five months on the patient, 30-year-old mother-of-two Claudia Castillo, is in perfect health, The Lancet reports. She needed the transplant to save a lung after contracting tuberculosis. The Colombian woman's airways had been damaged by the disease. Scientists from Bristol helped grow the cells for the transplant and the European team believes such tailor-made organs could become the norm. To make the new airway, the doctors took a donor windpipe, or trachea, from a patient who had recently died. Then they used strong chemicals and enzymes to wash away all of the cells from the donor trachea, leaving only a tissue scaffold made of the fibrous protein collagen. This gave them a structure to repopulate with cells from Ms Castillo herself, which could then be used in an operation to repair her damaged left bronchus - a branch of the windpipe.

He said that in 20 years time, virtually any transplant organ could be made in this way.  US scientists have already successfully implanted bladder patches grown in the laboratory from patients' own cells into people with bladder disease. The European research team, which also includes experts from the University of Padua and the Polytechnic of Milan in Italy, is applying for funding to do windpipe and voice box transplants in cancer patients.

Clinical trials could begin five years from now, they said. Between 50,000 and 60,000 people are diagnosed with cancer of the larynx each year in Europe, and scientists say about half them may be suitable candidates for tissue engineering transplants..

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02/06/2009 - Reconstructing mandibular defects using autologous tissue-engineered tooth and bone constructs
J Oral Maxillofac Surg. 2009 Feb;67(2):335-47

Abukawa H, Zhang W, Young CS, Asrican R, Vacanti JP, Kaban LB, Troulis MJ, Yelick PC.

Department of Oral and Maxillofacial Surgery, Massachusetts General Hospital, Harvard School of Dental Medicine, Boston, MA, USA.

PURPOSE: Current strategies for jaw reconstruction require multiple operations to replace bone and teeth. To improve on these methods, we investigated simultaneous mandibular and tooth reconstruction, using a Yucatan minipig model. MATERIALS AND METHODS: Tooth and bone constructs were prepared from third molar tooth tissue and iliac-crest bone marrow-derived osteoblasts isolated from, and implanted back into, the same pig as an autologous reconstruction. Implants were harvested after 12 and 20 weeks and evaluated by x-ray, ultrahigh-resolution volume computed tomographic (VCT), histological, and immunohistochemical analyses. RESULTS: Small tooth structures were identified, and consisted of organized dentin, enamel, pulp, and periodontal ligament tissues, surrounded by new bone. No dental tissues formed in implants without tooth-bud cells, and bone regeneration was observed to a limited extent. Immunohistochemical analyses using tooth-specific and bone-specific antibodies confirmed the identity of regenerated tissues. CONCLUSIONS: This pilot study supports the feasibility of tissue-engineering approaches for coordinated autologous tooth and mandible reconstruction, and provides a basis for future improvement of this technique for eventual clinical use in humans.

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02/06/2009 - Human dental pulp stem cells: from biology to clinical applications.
J Exp Zoolog B Mol Dev Evol. 2008 Dec 8

d'Aquino R, De Rosa A, Laino G, Caruso F, Guida L, Rullo R, Checchi V, Laino L, Tirino V, Papaccio G.

Dipartimento di Medicina Sperimentale, Sezione di Istologia ed Embriologia, TESLab, Secondo Ateneo di Napoli, Napoli, Italy.

Dental pulp stem cells (DPSCs) can be found within the "cell rich zone" of dental pulp. Their embryonic origin, from neural crests, explains their multipotency. Up to now, two groups have studied these cells extensively, albeit with different results. One group claims that these cells produce a "dentin-like tissue", whereas the other research group has demonstrated that these cells are capable of producing bone, both in vitro and in vivo. In addition, it has been reported that these cells can be easily cryopreserved and stored for long periods of time and still retain their multipotency and bone-producing capacity. Moreover, recent attention has been focused on tissue engineering and on the properties of these cells: several scaffolds have been used to promote 3-D tissue formation and studies have demonstrated that DPSCs show good adherence and bone tissue formation on microconcavity surface textures. In addition, adult bone tissue with good vascularization has been obtained in grafts. These results enforce the notion that DPSCs can be used successfully for tissue engineering. J. Exp. Zool. (Mol. Dev. Evol.) 310B, 2008. (c) 2008 Wiley-Liss, Inc.

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01/05/2009 - A Moment Of Tooth Advances to Regrow Decaying Choppers Offer More to Chew On Than You'd Think
Taken From:

By Joel Garreau
Washington Post Staff Writer
Sunday, January 4, 2009; 10:55 PM

It turns out wisdom teeth are prolific sources of adult stem cells needed to grow new teeth for you. From scratch. In your adult life, as you need them. In the near future. According to the National Institutes of Health.

"We're there, right now," said Pamela Robey, chief of the Craniofacial and Skeletal Diseases Branch at the National Institute of Dental and Craniofacial Research, part of the National Institutes of Health. "A lot of people will go and never lose a tooth. With good health care and proper habits, there's no reason to lose a tooth."

Regenerating a whole tooth is no less complicated than rebuilding a whole heart, said Songtao Shi, of the University of Southern California, who heads a team working on creating such a tooth. Not only do you have to create smart tissue (nerves), strong tissue (ligaments) and soft tissue (pulp), you've got to build enamel — by far the hardest structural element in the body. And you have to have openings for blood vessels and nerves. And you have to make the whole thing stick together. And you have to anchor it in bone. And then you have to make the entire arrangement last a lifetime in the juicy stew of bacteria that is your mouth.

It's a nuisance, but researchers are closing in on it. They think the tooth probably will be the first complex organ to be completely regenerated from stem cells. In part, this is because teeth are easily accessible.

So are adult stem cells, abundant in both wisdom and baby teeth, and your immune system won't reject your cells.

If you had been a great parent, like the University of Alabama's MacDougall, you would have saved your children's baby teeth in liquid nitrogen as sources of adult stem cells. So now MacDougall has the stem cells of her teenage sons -- Morgan, 17, and Mason, 14 -- from which to create future spare parts.

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12/22/2008 - Can we rescue salivary gland function after irradiation?
ScientificWorldJournal. 2008 Oct 3;8:959-62

Feng J, Coppes RP.

Department of Cell Biology, University Medical Center Groningen, University of Groningen, The Netherlands.

Hyposalivation induced by exposure of the salivary gland to radiation while treating head and neck cancer patients, can result in xerostomia (dry mouth syndrome), which burdens the patient with oral dryness or pain, dental caries, reduced taste and smell, increased risk for oral infections, hampered speech, and problems with food mastication. Stem cell therapy may be an option to reduce radiation-induced damage to the salivary glands permanently. This Directions in Science article reviews a recent study (Lombaert et al, 2008) using tissue stem cells to regenerate the salivary glands from cells that originate from putative stem cells residing in the ductal compartment. Lombaert et al showed restoration of function of irreversibly damaged mouse submandibular glands after intraglandular injection of an in vitro cultured c-Kit+ cell population containing salivary gland stem cells. The findings raise the prospect of clinical autologous salivary gland stem cell transplantation after radiotherapy.

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12/16/2008 - Restoring the function of salivary glands.
Oral Dis. 2008 Jan;14(1):15-24

Kagami H, Wang S, Hai B.

Department of Tissue Engineering, Nagoya University School of Medicine, Nagoya, Japan. kagami@ims.u-tokyo.ac.jp

Salivary gland destruction occurs as a result of various pathological conditions such as radiation therapy for head and neck cancer and Sjögren's syndrome. As saliva possesses self-cleaning and antibacterial capability, hyposalivation is known to deteriorate dental caries and periodontal disease. Furthermore, hyposalivation causes mastication and swallowing problems, burning sensation of the mouth and dysgeusia. Currently available treatments for dry mouth are prescription for artificial saliva, moisturizers and medications which induce salivation from the residual tissue. Unfortunately, these treatments cannot restore the acini functions. This review focuses on various efforts to restore the function of damaged salivary gland. First, the possibility of salivary gland regeneration and tissue engineering is discussed with reference to stem cells, growth factors and scaffold materials. Second, the current status of gene transfer to salivary glands is discussed.

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12/15/2008 - New Way To More Rapidly Generate Bone Tissue Developed
ScienceDaily (Dec. 19, 2008) — Using stem cell lines not typically combined, researchers at Columbia University Medical Center have designed a new way to "grow" bone and other tissues.


The inability to foster angiogenesis – a physiological process involving the growth of new blood vessels from pre-existing vessels – has been a major roadblock in tissue regeneration. Previous approaches have included the use of angiogenic growth factors and the fabrication of artificial blood vessels. However, there are problems associated with these approaches. Among these problems: artificially fabricated blood vessels do not readily branch out and network with host blood vessels, and blood vessels induced by angiogenic growth factors tend to be immature and "leaky."

To overcome these obstacles, a team of Columbia researchers has co-transplanted hematopoietic and mesenchymal stem/progenitor cells to promote the regeneration of vascularized tissues. What they found was that the tissue regenerated in bone more rapidly than when either type of stem cell was used alone.

The work by Jeremy Mao, DDS, Ph.D., published December 15 in PLoS ONE, takes a new approach: rarely have mesenchymal and hematopoietic cells been delivered in combination for the healing of defects and the treatment of diseases – partially due to the separate research communities in which these two cell groups are studied.

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11/10/2008 - Adelaide research to repair brain damage with stem cells from teeth

STROKE victims could one day give their back teeth to repair brain injuries, an Adelaide researcher predicts.

A team of scientists is investigating using stem cells harvested from adult teeth to repair brain damage.

It will be led by the newly created Centre for Stem Cell Research, which was launched yesterday at the University of Adelaide.

Almost 100 scientists and 80 students from 18 research groups across Adelaide are involved with the centre, which plans to develop therapies for diseases such as stroke, heart attack, cancer and cystic fibrosis.

It has been established that cells from adult teeth can be used to create stem cells that have the ability to form new brain tissue.

An experiment has begun to see whether these cells can repair stroke damage in the brains of rats.

Dr Simon Koblar of the University of Adelaide said human clinical trials would follow within five years if the experiments worked.

Dr Koblar said most of his patients in the clinic at Queen Elizabeth Hospital "would give gladly some of their teeth" to see even a small improvement in movement and brain function after a stroke.

"At the moment all I can do is, from day to day, say `wait and see'," he said.

Centre director Associate Professor Stan Gronthos was one of the first to realise that teeth stem cells were "a little bit different".

"They have the ability to form different structures in the craniofacial region including brain tissue as well," he said.

Researcher Dr Agnes Arthur helped prove stem cells from adult teeth could make brain cells. Her work has been published in the journal Stem Cells.

She said she wanted to do something that could have clinical implications, "down the track" and was happy with the way the research turned out.

September 15, 2008 11:30pm

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11/04/2008 - Cardiac differentiation is driven by NKX2.5 and GATA4 nuclear translocation in tissue specific mesenchymal stem cells.
Stem Cells Dev. 2008 Nov 4. [Epub ahead of print]

Armiñán A, Gandia C, Bartual C, Garcia-Verdugo JM, Lledó E, Mirabet V, Llop M, Barea J, Montero JA, Sepúlveda P.

Centro de Investigación Príncipe Felipe, Unit of Cardioregeneration, Valencia, Valencia, Spain; aarminan@cipf.es.

Myocardial infarction is a major public health problem that causes significant mortality despite recent advances in its prevention and treatment. Therefore, approaches based on adult stem cells represent a promising alternative to conventional therapies for this life-threatening condition. Mesenchymal stem cells (MSC) are self-renewing pluripotent cells that have been isolated from multiple tissues and differentiate to various cell types. Here we have analysed the capacity of MSC from human bone marrow (BMSC), adipose tissue (ATSC) and dental pulp (DPSC) to differentiate to cells with a cardiac phenotype. Differentiation of MSC was induced by long-term co-culture with neonatal rat cardiomyocytes (CM). Shortly after the establishment of MSC-CM co-cultures, expression of connexin 43 and the cardiac specific markers Troponin I, &#946;-MHC, Atrial natriuretic peptide (ANP) and &#945;-Sarcomeric actinin was detected in BMSC, ATSC and DPSC. Expression of differentiation markers increased over time in the co-cultures, reaching the highest levels at 4 weeks. Translocation of the transcription factors NKX2.5 and GATA4 to the nucleus was observed in all three cultures of MSC during the differentiation process; moreover, nuclear localization of NKX2.5 and GATA4 correlated with expression of &#945;-Sarcomeric actinin. These changes were accompanied by an increase in myofibril organization in the resulting CM-like cells as analyzed by electron microscopy. Thus, our results provide novel information regarding the differentiation of tissue-specific MSC to cardiomyocytes and support the potential use of MSC in cell-based cardiac therapies.

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11/01/2008 - Prosthodontics and implants: from xenodontics to biodontics.
Rossomando EF.

Center for Research and Education in Technology Evaluation, University of Connecticut School of Dental Medicine, Farmington, Connecticut, USA. erossomando@uchc.edu

To date, the restoration, repair, and replacement of lost and damaged teeth used metals and plastics, nonbiological materials. This type of dentistry has been referred to as "xenodontics." This article discusses the progress in developing a tissue-engineered tooth derived from stem cells. The use of biologically derived replacements for lost and missing teeth is called "biodontics." The technical difficulties that dentists had to overcome historically in restoring, replacing, and repairing lost and damaged teeth are reviewed. The inventiveness and creativity of our professional ancestors in using materials available to restore damaged teeth and to make artificial teeth and denture bases are discussed. This section concludes with the introduction of plastics for both the fabrication of prosthetic teeth and denture bases. The history of root implants is introduced, concluding with the use of titanium. This article concludes by noting that, for the most part, dental schools are just beginning to include implants or computer-aided design (CAD) and computer-aided manufacturing (CAM) into the curriculum and that this process should be accelerated to ensure our graduates are fully prepared to practice efficiently and successfully.

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09/22/2008 - Pittsburgh researchers identify source of multipotent stem cells with broad regenerative potentia

Public release date: 22-Sep-2008

Results of Children's Hospital of Pittsburgh of UPMC study published in journal Cell Stem Cell

In a promising finding for the field of regenerative medicine, stem cell researchers at Children's Hospital of Pittsburgh of UPMC have identified a source of adult stem cells found on the walls of blood vessels with the unlimited potential to differentiate into human tissues such as bone, cartilage and muscle.

The scientists, led by Bruno Péault, PhD, deputy director of the Stem Cell Research Center at Children's Hospital, identified cells known as pericytes that are multipotent, meaning they have broad developmental potential. Pericytes are found on the walls of small blood vessels such as capillaries and microvessels throughout the body and have the potential to be extracted and grown into many types of tissues, according to the study.

"This finding marks the first direct evidence of the source of multipotent adult stem cells known as mesenchymal stem cells. We believe pericytes represent one of the most promising sources of multipotent stem cells that scientists have been searching for in the quest to make regenerative medicine possible," Dr. Péault said. "The encouraging aspect of this source is that blood vessels are the one structure that all tissues in the human body have in common. These cells can be extracted easily and painlessly from convenient sources such as fat tissue, dental pulp, umbilical cord and placental tissue, then grown in culture to large numbers and, possibly, re-injected into the patient to heal a broken bone, a failing joint or an injured muscle."

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09/17/2008 - Teeth Can Yield Stem Cells, Scientists Say

Amitabh Avasthi  for National Geographics News  August 27, 2008

Dental pulp from wisdom teeth could be a new source of therapeutic stem cells, Japanese researchers announced recently

Like embryonic stem cells, the new cells—known as mesenchymal stem cells—are capable of developing into a variety of tissues, including bone, cartilage, and fat. These new lines of stem cells can be created without the use of an embryo—possibly sidestepping controversy.

In many countries adults routinely get minor surgeries to remove wisdom teeth.

"The [wisdom] tooth is usually discarded into trash, so there are no ethical concerns," said Hajime Ohgushi, principal research scientist at the National Institute of Advanced Industrial Science and Technology in the Hyogo Prefecture, Japan.

However, unlike embryonic stem cells, the newfound cells cannot morph into almost any type of cell in the body.

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09/17/2008 - Tooth stem cells give brain surgery hopes

Posted Tue Sep 16, 2008 5:24pm AEST
Updated Tue Sep 16, 2008 6:07pm AEST


University of Adelaide researchers say they are close to repairing stroke-damaged brains using stem cells taken from teeth.

The research is being done at the university's Centre for Stem Cell Research, which has been officially launched at a function in Adelaide.

Project coordinator Dr Simon Koblar says the research involves dental pulp stem cells.

"So we've actually taken them from young people that have impacted molars in their mouth and we remove the tooth and you can break it open and inside the tooth are some stem cells, so you can grow them in a test tube," he explained.

The procedure has been tested on rats and, if all goes to plan, there may be human trials in the next five years.

The research has funding support from the Catholic Church because it avoids the ethical dilemma involved with use of embryonic stem cells.

"The Catholic Church obviously has a moral objection with embryonic stem cells and they decided the best way of doing that would be to offer a grant every two years with groups that use adult stem cell populations," Dr Koblar said.

The new stem cell centre will be used by almost 100 scientists and 80 research students.

Adelaide University hopes it can help put South Australian researchers at the forefront of stem cell research in Australia.

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07/03/2008 - Early transplantation of human immature dental pulp stem cells from baby teeth to golden retriever muscular dystrophy (GRMD) dogs: local or systemic?
Journal of Translational Medicine 2008

Author: Irina Kerkis, Carlos E Ambrosio, Alexandre Kerkis, Daniele S Martins, Eder Zucconi, Simone AS Fonseca, Rosa M Cabral, Carlos MC Maranduba, Thais P Gaiad, Adriana C Morini, Natassia M Vieira, Marina P Brolio, Osvaldo A Sant'Anna, Maria A Miglino

The golden retriever muscular dystrophy (GRMD) dogs represent the best available animal model for therapeutic trials aiming at the future treatment of human Duchenne muscular dystrophy (DMD). We have obtained a rare litter of six GRMD dogs (3 males and 3 females) born from an affected male and a carrier female which were submitted to a therapeutic trial with adult human stem cells to investigate their capacity to engraft into dogs muscles by local as compared to systemic injection without any immunosuppression.

Methods: Human Immature Dental Pulp Stem Cells (hIDPSC) were transplanted into 4 littermate dogs aged 28 to 40 days by either arterial or muscular injections.

Two non-injected dogs were kept as controls. Clinical translation effects were analyzed since immune reactions by blood exams and physical scores capacity of each dog.

Samples from biopsies were checked by immunohistochemistry (dystrophin markers) and FISH for human probes. Results and Discussion: We analyzed the cells' ability in respect to migrate, engraftment, and myogenic potential, and the expression of human dystrophin in affected muscles.

Additionally, the efficiency of single and consecutive early transplantation was compared. Chimeric muscle fibers were detected by immunofluorescence and fluorescent in situ hybridisation (FISH) using human antibodies and X and Y DNA probes.

No signs of immune rejection were observed and these results suggested that hIDPSC cell transplantation may be done without immunosuppression. We showed that hIDPSC presented significant engraftment in GRMD dog muscles, although human dystrophin expression was modest and limited to several muscle fibers.

Better clinical condition was also observed in the dog, which received monthly arterial injections and is still clinically stable at 25 months of age.

Conclusions: Our data suggested that systemic multiple deliveries seemed more effective than local injections.

These findings open important avenues for further researches.

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07/02/2008 - Pulling a tooth could lead to tailor-made sperm
08 July 2008
NewScientist.com news service
Linda Geddes


Could sacrificing a tooth enable some infertile men to father children? That's the goal of researchers in Brazil, who suggest that stem cells from human teeth can be coaxed into becoming sperm by injecting them into the testes of mice.

Irina Kerkis of the Butantan Institute, São Paulo, and her colleagues injected stem cells from the dental pulp of human teeth into the testes of live mice.

The cells seemed to migrate to the tubules where sperm usually mature and differentiate into cells resembling human sperm.

However, the process was inefficient and some of the human cells fused with mouse cells – a problem that would have to be solved before the technique could be used therapeutically.

Baby teeth

The cells were also taken from baby teeth, so it is unclear if the approach would work with teeth from adult men.

"I think we are on the right track, but we need to understand more about the mechanism," says Kerkis, whose team will present the results at the meeting of the European Society of Human Reproduction and Embryology in Barcelona, Spain, on 9 July.

Other researchers are sceptical. It takes human sperm several weeks to develop, yet the Brazilian team's cells seemed to have matured within nine days.

Given that human sperm stem cells have previously failed to mature in mouse testes, it seems unlikely that dental cells would fare better, adds Robin Lovell-Badge of the National Institute for Medical Research in London, UK.

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07/02/2008 - 73 CURRENT HUMAN CLINICAL APPLICATIONS USING ADULT STEM CELLS *
73 CURRENT HUMAN CLINICAL APPLICATIONS USING ADULT STEM CELLS *

* There are no current clinical trials in humans with embryonic stem cells:
“It is nearly certain that the [human] clinical benefits of the [embryonic stem cell] research are years or decades away. This is a message that desperate families and patients will not want to hear.”
— Science, June 17, 2005
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06/23/2008 - Postnatal stem/progenitor cells derived from the dental pulp of adult chimpanzee
BMC Cell Biol. 2008 Apr 22;9:20

Cheng PH, Snyder B, Fillos D, Ibegbu CC, Huang AH, Chan AW.

Neuroscience Division, Yerkes National Primate Research Center, Atlanta, USA. pcheng@genetics.emory.edu

BACKGROUND: Chimpanzee dental pulp stem/stromal cells (ChDPSCs) are very similar to human bone marrow derived mesenchymal stem/stromal cells (hBMSCs) as demonstrated by the expression pattern of cell surface markers and their multipotent differentiation capability. RESULTS: ChDPSCs were isolated from an incisor and a canine of a forty-seven year old female chimpanzee. A homogenous population of ChDPSCs was established in early culture at a high proliferation rate and verified by the expression pattern of thirteen cell surface markers. The ChDPSCs are multipotent and were capable of differentiating into osteogenic, adipogenic and chondrogenic lineages under appropriate in vitro culture conditions. ChDPSCs also express stem cell (Sox-2, Nanog, Rex-1, Oct-4) and osteogenic (Osteonectin, osteocalcin, osteopontin) markers, which is comparable to reported results of rhesus monkey BMSCs (rBMSCs), hBMSCs and hDPSCs. Although ChDPSCs vigorously proliferated during the initial phase and gradually decreased in subsequent passages, the telomere length indicated that telomerase activity was not significantly reduced. CONCLUSION: These results demonstrate that ChDPSCs can be efficiently isolated from post-mortem teeth of adult chimpanzees and are multipotent. Due to the almost identical genome composition of humans and chimpanzees, there is an emergent need for defining the new role of chimpanzee modeling in comparative medicine. Teeth are easy to recover at necropsy and easy to preserve prior to the retrieval of dental pulp for stem/stromal cells isolation. Therefore, the establishment of ChDPSCs would preserve and maximize the applications of such a unique and invaluable animal model, and could advance the understanding of cellular functions and differentiation control of adult stem cells in higher primates.

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05/14/2008 - Multipotent cells from the human third molar: feasibility of cell-based therapy for liver disease
Differentiation  18 Dec 2007

Etsuko Ikeda, Kiyohito Yagi, Midori Kojima, Takahiro Yagyuu, Akira Ohshima, Satoshi Sobajima, Mika Tadokoro, Yoshihiro Katsube, Katsuhiro Isoda, Masuo Kondoh, Masaya Kawase, Masahiro J Go, Hisashi Adachi, Yukiharu Yokota, Tadaaki Kirita, Hajime Ohgushi

Adult stem cells have been reported to exist in various tissues. The isolation of high-quality human stem cells that can be used for regeneration of fatal deseases from accessible resources is an important advance in stem cell research. In the present study, we identified a novel stem cell, which we named tooth germ progenitor cells (TGPCs), from discarded third molar, commonly called as wisdom teeth. We demonstrated the characterization and distinctiveness of the TGPCs, and found that TGPCs showed high proliferation activity and capability to differentiate in vitro into cells of three germ layers including osteoblasts, neural cells, and hepatocytes. TGPCs were examined by the transplantation into a carbon tetrachloride (CCl4)-treated liver injured rat to determine whether this novel cell source might be useful for cell-based therapy to treat liver diseases. The successful engraftment of the TGPCs was demonstrated by PKH26 fluorescence in the recipient's rat as to liver at 4 weeks after transplantation. The TGPCs prevented the progression of liver fibrosis in the liver of CCl4-treated rats and contributed to the restoration of liver function, as assessed by the measurement of hepatic serum markers aspartate aminotransferase and alanine aminotransferase. Furthermore, the liver functions, observed by the levels of serum bilirubin and albumin, appeared to be improved following transplantation of TGPCs. These findings suggest that multipotent TGPCs are one of the candidates for cell-based therapy to treat liver diseases and offer unprecedented opportunities for developing therapies in treating tissue repair and regeneration
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04/29/2008 - Stem cells of dental pulp