Cryopreserved hepatic progenitor cells derived from human embryonic stem cells can arrest progression of liver fibrosis in rats.

Hepatocytes generated from human embryonic stem cells (hESCs) are considered to be an excellent candidate for restoring the liver function deficiencies. We have earlier standardized a three-step differentiation protocol to generate functional hepatocyte-like cells (HLCs) from hESCs, which expressed the major hepatic markers. We have also found that the HLCs remain stable and functional even after extended period of in vitro culture and cryopreservation. In the present study, we have aimed to investigate the therapeutic potential of cryopreserved-thawed hESC-derived hepatic progenitor cells following transplantation in carbon tetrachloride-induced fibrotic rat livers. Significant therapeutic effects, including improved hepatic histology and normal serum biochemistry of hepatic enzymes along with increased survival rate, were observed in the cell transplanted rats. This result is an encouraging indication to develop methods for clinical application of hESC-derived hepatic lineage cells.

Dopaminergic cells, derived from a high efficiency differentiation protocol from umbilical cord derived mesenchymal stem cells, alleviate symptoms in a Parkinson's disease rodent model.

Mesenchymal stem cells (MSCs) could be an alternative to foetal cells in the treatment of several neurodegenerative diseases, especially Parkinson's disease (PD). We have previously demonstrated the functional efficacy of the undifferentiated bone marrow MSCs (BMMSCs) cultured in a xenofree conditions in PD animal models. We now demonstrate isolation of MSCs from the umbilical cord matrix tissue and assess their safety and efficacy to improve Parkinsonian symptoms in an in vivo animal model. The efficacy of MSCs from BM and umbilical cord in the PD animal mode has also been studied, and more importantly the efficacy of using differentiated UCMSC (D-UCMSCs) to dopaminergic phenotype. Phenotypically, UCMSCs expressed higher levels of SSEA4 compared to BMMSCs. Analysis of differentiated cells showed that D-UCMSCs expressed significant levels of Tyrosine Hydroxyalse and Nurr1 compared to D-BMMSCs. The in vivo efficacy of the differentiated and undifferentiated cell types in the Parkinsonian rats showed that D-UCMSCs improved the symptoms throughout a year of study. Differentiated cell types are potentially better for clinical use than the undifferentiated type, provided they are made available at the site of action in adequate numbers. MSCs are less immunogenic and immunomodulatory, which opens up the further possibility of using these cells in allogeneic settings. This could be a novel cell therapy application, especially when getting autochthonous cells is difficult.

Efficacy and safety of autologous cultured melanocytes delivered on poly (DL-lactic acid) film: a prospective, open-label, randomized, multicenter study.

BACKGROUND: Small vitiliginous patches have been treated with epidermal grafts or their cell suspensions. In an attempt to overcome some of the shortcomings of cell suspension delivery, we have delivered melanocytes on a polymeric film. OBJECTIVES: To evaluate the clinical effectiveness of a cultured graft consisting of autologous cultured melanocytes on a poly (DL-lactic acid) (PLA) film in subjects with stable vitiligo. METHODS: A prospective open-label, randomized, multicenter clinical trial was conducted with 22 patients. Each subject was treated with cultured graft and polyurethane dressing (control arm) after epidermal ablation and followed for up to 9 months. The extent of repigmentation in the treated sites was compared with that control sites at days 90, 180, and 270. RESULTS: In the treatment arm, a minimum of 70% repigmentation was observed in five subjects at day 90; nine at day 180, and 10 at day 270. In the control arm, only one subject showed repigmentation until day 270. None of the test sites reported any recurrence of vitiliginous patches by the end of the study. CONCLUSIONS: Cultured melanocytes delivered on PLA film were efficacious and safe when applied on patients with stable vitiligo.

Molecular and cellular characterization of expanded and cryopreserved human limbal epithelial stem cells reveal unique immunological properties.

Transplantation of ex vivo expanded autologous limbal stem cells into the diseased eye of patients with limbal stem cell deficiency (LSCD) has been in practice worldwide. However, isolation of limbal tissue from the normal eye of the patient with unilateral LSCD still remains a major concern for the donor. More importantly, autologous cell transplantation is not a viable option for patients with bilateral LSCD. The objective of the current study was to determine the expansion potential of human limbal epithelial stem cells (hLESCs) for their possible use in allo-transplantation. A total of six limbal biopsy samples were cultured and expanded in vitro up to passage level 1 (P-1), at which point the hLESCs were cryopreserved. Semi-quantitative RT-PCR and immunophenotypic analysis revealed that hLESCs obtained before and after cryopreservation retained the expression of major limbal epithelial stem cell markers such as p63, SSEA-4, ABCG2, cytokeratin 19 (CK19), integrin ß1 and vimentin. One notable difference was that while P-0 hLESCs expressed HLA-DR mRNA, no HLA-DR gene expression was observed with the expanded and cryopreserved samples. Human LESCs did not express costimulatory proteins CD80 or B7-DC but expressed significant levels of CD86, B7-H1 and HLA-ABC molecules on the cell surface. Treatment of hLESCs with IFN-γ induced the expression of HLA-DR, indoleamine 2,3-dioxygenase (IDO) and HLA-G on these cells. Cultured hLESCs were unable to stimulate allogeneic T cell proliferation in vitro even in the presence of pro-inflammatory cytokine, IFN-γ. These results indicate that cryopreserved hLESCs are non-immunogenic in nature and express negative immunoregulatory molecules which may be critical for their survival in an allogeneic environment.

Immunosuppressive properties of human umbilical cord-derived mesenchymal stem cells: role of B7-H1 and IDO.

Umbilical cord is a rich source of mesenchymal stromal or stem cells (MSCs) that can be used for developing allogeneic cell therapy to treat intractable diseases. In this report, we present evidence that umbilical cord-derived MSCs (UCMSCs) possess important immunomodulatory properties that may enable them to survive in an allogeneic environment. UCMSCs do not express human leukocyte antigen (HLA)-DR and co-stimulatory molecules CD80 and CD86 that are required for T-cell activation. More importantly, UCMSCs constitutively express a negative regulator of T-cell activation, B7-H1, and its expression is increased after interferon-γ (IFN-γ) treatment. In addition, IFN-γ treatment induced indoleamine 2,3-dioxygenase (IDO) and HLA-DR expression in UCMSCs. Neither control nor IFN-γ-treated UCMSCs stimulated allogeneic T-cell proliferation, and both cell populations inhibited third-party dendritic cell (DC)-mediated allostimulatory activity. Addition of a B7-H1-specific blocking antibody or an IDO inhibitor, 1 methyl tryptophan (1-MT) abrogated the T-cell immunosuppressive activity of these cells. Furthermore, UCMSCs prevented the differentiation and maturation of peripheral blood monocyte-derived DCs, and augmented the generation of regulatory T cells (Tregs) in culture. The immunosuppressive effects of UCMSCs are largely mediated by cell-to-cell contact, although some inhibitory activity was observed with cell-free supernatant. Our study suggests that these immunomodulatory properties of UCMSCs could potentially improve the outcome of allogeneic stem cell therapy.

Intrinsic properties and external factors determine the differentiation bias of human embryonic stem cell lines.

A major goal of human embryonic stem cell (hESC) research is to regulate differentiation through external means to generate specific cell types with high purity for regenerative medicine applications. Although all hESC lines express pluripotency-associated genes, their differentiation ability to various lineages differs considerably. We have compared spontaneous differentiation propensity of the two hESC lines, RelicellhES1 and BG01. Spontaneous differentiation of hESC lines grown in different media conditions was followed by differentiation using two methods. Kinetic data generated by real-time gene expression studies for differentiated cell types were analyzed, and confirmed at protein levels. Both cell lines showed upregulation of genes associated with the 3 germ layers, although stark contrast was evident in the magnitude of upregulation of lineage specific genes. A distinct difference was also found in the rate at which the pluripoteny factors, Oct-4 and Nanog, were downregulated during differentiation. Once differentiation was initiated, both Oct-4 and Nanog gene expression was drastically reduced in RelicellhES1, whereas a gradual decrease was observed in BG01. A clear trend is seen in RelicellhES1 to differentiate into neuroectodermal and mesenchymal lineages, whereas BG01 cells are more prone to mesoderm and endoderm development. In addition, suspension versus plated methods of cell culture significantly influenced the outcome of differentiation of certain types of cells. Results obtained by spontaneous differentiation of hESCs were also amplified by induced differentiation. Thus, differential rates of downregulation of pluripotency markers along with culture conditions seem to play an important role in determining the developmental bias of human ES cell lines.

Tansplantation of autologous bone marrow derived mesenchymal stem cells trans-epicardially in patients undergoing coronary bypass surgery.

BACKGROUND: Myocardial Infarction (MI) hampers cardiac performance by ventricular remodeling which is a major cause of heart failure or death. Conventional drug therapies like beta blockers, angiotensin-converting enzyme may delay remodeling but there is no single therapeutic regimen available that can prevent or reverse the process of myocardial injury. Interventional therapies and surgical procedures improve or normalize coronary blood flow greatly. Experimental data suggests that bone marrow derived Mesenchymal Stem Cells (MSCs) may contribute to the healing of Myocardial infarction. We present our findings on the use of bone marrow derived MSCs for Myocardial Infarction wherein the cells were injected in and around the infarct region epicardially during coronary bypass surgery. METHODS & MATERIALS: 31 patients selected to undergo Coronary Artery Bypass Graft (CABG) as a treatment option for myocardial infarction formed the subject matter of our study. One patient withdrew consent before receiving our therapy and was excluded from the study. 15 patients (all men, average age 57) formed the test arm who underwent CABG plus Bone Marrow Mesenchymal Stem Cells (BMMSCs) transplantation whereas another 15 patients underwent conventional CABG only (14 men and 1 woman, mean age 57) served as the control arm. The cell transplantation consisted of injecting BMMSCs in the border zone of the clearly visible infarcted area transepicardially. The absolute number of MSCs injected ranged between 3 million and 26 million cells. RESULTS: The data for change from baseline in the area of infarct was collected at 3 months and 6 months during the study and analyzed using paired t-tests. The mean percentage perfusion improvement from baseline in the area of infarct supplied by the Left Anterior Descending Artery (LAD) was higher in the cases (35.8%) as compared to the controls (11.3%) at 3 months post treatment (p value < 0.05). There were three cases of arrhythmia, and none of the adverse events recorded were due to the investigational product. Improvement in the ejection fraction was similar in the cases and controls. CONCLUSIONS: This study demonstrates that trans-epicardial uses of mesenchymal stem cells are very safe and feasible. Correction of perfusion defect is very encouraging. Larger studies using higher doses of mesenchymal stem cells may bring about better understanding.

Optimization of the inventory size of the public cord blood program--the Indian context.

BACKGROUND: There are reportedly more than 250,000 cord blood units [CBU] available in cord blood banks world over, yet, there are many who are unable to get a suitable match. Being the pioneer to set up the first and only public cord blood bank in India, we needed to strategize the pool size that will meet the transplantation needs of the people of Indian origin, worldwide. PURPOSE: To define the optimum size of this public cord blood repository [CBR] that will give at least one 5/6 HLA match to a defined number of cord blood graft requests. METHODS: We checked the trend of human Leukocyte antigen [HLA] match graft offerings, to 112 random requests from a database of 1800 CBUs. The HLA match function was performed using an 'in house' built and validated software. The pattern of availability of the matches was used as the basis of our study. We then performed a probability analysis to check the probable pool size that would offer at least one acceptable match to all the 112 requests. RESULTS: With an inventory of 1800 units, we could offer 4/6 matches to about 99% and 5/6 matches to approximately only 29% and 6/6 matches to only 7% of the 112 random requests. Thus, acceptable matches were offered to about 30% of the requests received in the period and database considered for this study. CONCLUSION: By employing probability analysis, we concluded that, by doubling the size, we will probably offer at least one 5/6 match to each requester, and from a pool size of about 55500 grafts, we may offer a full house (6/6 match) to the same number of requisitions. Genetic homology between the recipient and donor base, increases the probability of match availability. A good ethnic representation of the Indian population in our CBR plays a significant role in match availability.

Clinical grade mesenchymal stem cells transdifferentiated under xenofree conditions alleviates motor deficiencies in a rat model of Parkinson's disease.

UNLABELLED: Bone marrow derived mesenchymal stem cells (BMMSCs) is a valid, definitive candidate for repair of damaged tissues in degenerative disorders in general and neurological diseases in particular. We have standardized the processing conditions for proliferation of BMMSCs using xenofree medium and checked their in vitro and in vivo neurogenic potential. METHOD: The proliferative potential of BMMSCs was analyzed using xenofree media and functionality checked by transplantation into Parkinson's disease (PD) animal models. In vitro neuronal differentiation was investigated by neuronal induction media supplemented with growth factors. Differentiated cells were characterized at cellular and molecular levels. In vitro functionality estimated by dopamine secretion. RESULTS: A pure population of BMMSCs showing an 8-10 fold expansion was obtained using xenofree media. On differentiation to neuronal lineage, they exhibited neuronal morphology. Detectable levels of dopamine (1.93 ng/ml) were secreted into the culture media of differentiated cells. There was a significant behavioural improvement in PD models 3 months post transplantation. CONCLUSION: Our study demonstrates that BMMSCs can be transdifferentiated efficiently into functional dopaminergic neurons both in vitro and in vivo. This holds immense clinical potential as a replacement therapy for PD and other neurodegenerative diseases.

Significance of CD34 Negative Hematopoietic Stem Cells and CD34 Positive Mesenchymal Stem Cells - A Valuable Dimension to the Current Understanding.

BACKGROUND: The strategy to expand CD34+ hematopoietic stem cells (HSCs) is being increasingly practiced to meet the demand for a higher cell dose. This is for hematopoietic reconstitution in patients with higher body weights. Interestingly, literature reports show that CD34- (CD34 negative) cell population also possesses the potential to reconstitute the bone marrow & in a certain phase, converts them into CD34+ phenotype. The current practice of positive selection of CD34+ HSCs by eliminating rest of the (CD34-) population for expansion could probably pose a risk of losing valuable HSCs with good reconstitution potentials. MSCs (Mesenchymal Stem Cells) hold great promise for use in various regenerative medicine applications. International Society for Cellular Therapy (ISCT) defined MSCs to be CD34 negative; tissue resident MSCs and peripheral blood-derived MSCs express CD34 on their surface even in vitro, though up to limited passages. This interesting observation of CD34 positive expression displayed in vivo by non-hematopoietic cell types such as MSCs was intriguing, thus prompting a detailed review of its significance, if any. OBJECTIVE: Based on an extensive review, we strongly believe that CD34 expression in MSCs has some significant role in hematopoietic reconstitution & in regeneration of degenerated tissues. The concept of poor CD34 expression or stunted expression by certain MSCs should not be ignored. Several interesting research findings are in agreement with our assumption. However, it still leaves behind several unanswered questions that can only be addressed through detailed studies of phenotypic developmental pathways of MSCs.

Umbilical Cord Derived Mesenchymal Stem Cells Useful in Insulin Production - Another Opportunity in Cell Therapy.

BACKGROUND AND OBJECTIVES: Type 1 Diabetes Mellitus (T1DM) is an autoimmune disorder resulting out of T cell mediated destruction of pancreatic beta cells. Immunomodulatory properties of mesenchymal stem cells may help to regenerate beta cells and/or prevent further destruction of remnant, unaffected beta cells in diabetes. We have assessed the ability of umbilical cord derived MSCs (UCMSCs) to differentiate into functional islet cells in vitro. METHODS AND RESULTS: We have isolated UCMSCs and allowed sequential exposure of various inducing agents and growth factors. We characterized these cells for confirmation of the presence of islet cell markers and their functionality. The spindle shaped undifferentiated UCMSCs, change their morphology to become triangular in shape. These cells then come together to form the islet like structures which then grow in size and mature over time. These cells express pancreatic and duodenal homeobox -1 (PDX-1), neurogenin 3 (Ngn-3), glucose transporter 2 (Glut 2) and other pancreatic cell markers like glucagon, somatostatin and pancreatic polypeptide and lose expression of MSC markers like CD73 and CD105. They were functionally active as demonstrated by release of physiological insulin and C-peptide in response to elevated glucose concentrations. CONCLUSIONS: Pancreatic islet like cells with desired functionality can thus be obtained in reasonable numbers from undifferentiated UCMSCs in vitro. This could help in establishing a "very definitive source" of islet like cells for cell therapy. UCMSCs could thus be a game changer in treatment of diabetes.

Long-term culture and cryopreservation does not affect the stability and functionality of human embryonic stem cell-derived hepatocyte-like cells.

Human embryonic stem cells (hESCs) are predicted to be an unlimited source of hepatocytes which can pave the way for applications such as cell replacement therapies or as a model of human development or even to predict the hepatotoxicity of drug compounds. We have optimized a 23-d differentiation protocol to generate hepatocyte-like cells (HLCs) from hESCs, obtaining a relatively pure population which expresses the major hepatic markers and is functional and mature. The stability of the HLCs in terms of hepato-specific marker expression and functionality was found to be intact even after an extended period of in vitro culture and cryopreservation. The hESC-derived HLCs have shown the capability to display sensitivity and an alteration in the level of CYP enzyme upon drug induction. This illustrates the potential of such assays in predicting the hepatotoxicity of a drug compound leading to advancement of pharmacology.

Natural killer cells: In health and disease.

Natural killer (NK) cells constitute our bodies' frontline defense system, guarding against tumors and launching attacks against infections. The activities of NK cells are regulated by the interaction of various receptors expressed on their surfaces with cell surface ligands. While the role of NK cells in controlling tumor activity is relatively clear, the fact that they are also linked to various other disease conditions is now being highlighted. Here, we present an overview of the role of NK cells during normal body state as well as under diseased state. We discuss the possible utilization of these powerful cells as immunotherapeutic agents in combating diseases such as asthma, autoimmune diseases, and HIV-AIDS. This review also outlines current challenges in NK cell therapy.

Potential of Mesenchymal Stem Cell based application in Cancer.

Stem cell based treatments are being increasingly explored for their possible potential to treat various cancers. Mesenchymal stem cells believed to possess anti-tumor potential and are preferred for their properties like immune privileged nature, ability to migrate to the site of tumor and capability for multilineage differentiation. This tumor tropism property of MSCs could be utilized to deliver anti-tumor biological agents to the site of tumor. In a tumor micro-environment, MSCs are believed to play both, a pro-tumorigenic and an anti-tumorigenic role. However, this is dependent on a host of factors like, types of MSCs, its source, type of cancer cell line under investigation, in vivo or in vitro conditions, factors secreted by MSCs and interactions between MSCs, host's immune cells and cancer cells. Among several cytokines secreted by MSCs, TRAIL (Tumor necrosis factor related apoptosis inducing ligand) is reported to be pro-apoptotic for tumor cells. The MSCs from bone marrow and adipose tissue have been studied quite extensively. Deriving MSCs from sources such as umbilical cord blood and umbilical cord tissue is relatively easier. Umbilical cord tissue preferred for MSC derivation due to their abundant availability. These MSCs believed to up regulate TRAIL expression in MSC-cancer cell co-culture system resulting in induction of apoptosis in cancer cells. However, umbilical cord tissue derived MSCs needs to be studied for expression pattern of TRAIL in a co-culture system. We present a review article on different studies reporting both, pro-tumorigenic and anti-tumorigenic properties of MSCs.

Preparation and characterization of silver nanoparticle loaded amorphous hydrogel of carboxymethylcellulose for infected wounds.

There is a growing demand for an appropriate and safe antimicrobial dressing to treat infected deep wounds. An amorphous gel formulation (SNP-CMC), containing silver nanoparticles (SNPs) and carboxymethylcellulose (CMC), was prepared in one step by the reduction of silver nitrate in situ. Spectrophotometric and microscopic analysis revealed that the SNPs were 7-21 nm in diameter. In simulated wound experiments, SNP-CMC gel was found to absorb 80.48 ± 4.69% w/w of saline and donate 17.43 ± 0.76% w/w of moisture within 24h indicating its dual fluid affinity. Cytocompatibility of the gel was assessed by proliferation studies with primary human skin cells. The antimicrobial activity studies showed that SNP-CMC containing 50 ppm of SNPs was effective against the growth of both Gram negative and Gram positive strains including methicillin-resistant Staphylococcus aureus (MRSA). These results indicate that SNP-CMC could be ideal for the treatment of deep infected wounds.

Paracrine factors secreted by umbilical cord-derived mesenchymal stem cells induce angiogenesis in vitro by a VEGF-independent pathway.

Improvement in angiogenesis using mesenchymal stem cells (MSCs) is evolving as an option in patients with vascular insufficiencies. The paracrine factors secreted by MSCs have been attributed to the angiogenic response. This study was conducted to identify the factors secreted by umbilical cord-derived MSCs (UCMSCs) that might play a role in angiogenesis. To this aim, we evaluated the presence of well known proangiogenic factors in the conditioned media (CM) derived from UCMSCs by ELISA. While vascular endothelial growth factor (VEGF), a well known angiogenic factor, was not detected in the CM, gene expression was nevertheless detected in these cells. Further investigations revealed the presence of soluble VEGF receptors (sVEGF-R1 and R2) that were capable of neutralizing exogenous VEGF. Human umbilical cord vein-derived endothelial cells exposed in vitro to CM, in comparison to control media, showed improved migration (P<0.007) and capillary-like network formation (P<0.001) with no significant change in endothelial cell proliferation. The angiogenic response observed with the paracrine factors secreted by UCMSC could be due to the presence of significant levels of a metalloprotease and matrix metalloproteases-2 (237.4±47.1 ng/10(6) cells). Data suggest that a VEGF-independent pathway is involved in the angiogenic response observed with endothelial cells in the presence of UCMSC-CM.

A non-invasive method to evaluate the efficacy of human myoblast in botulinum-A toxin induced stress urinary incontinence model in rats.

PURPOSE: To develop a simple non-invasive method to assess the efficacy of a cell based therapy for treating stress urinary incontinence (SUI). MATERIALS AND METHODS: In this study, skeletal myoblasts were used as candidate therapy to reverse SUI. The SUI model was created in rats using periurethral injection of botulinum-A toxin injection. Two weeks later, the rats were administered saline and the level of continence in each botulinum-A toxin treated and control animals was assessed by the extent of voiding using metabolic cages. To determine the efficacy of myoblasts to reverse SUI, botulinum-A toxin treated incontinent rats were injected with either cultured human skeletal myoblasts or with buffered saline (sham control). Two weeks post implantation, the extent of continence was evaluated as mentioned above. RESULTS: The difference in void volume between botulinum-A toxin -treated and control rats were significant. Histological analysis of the urethra showed remarkable atrophy of the muscular layer. A significant reversal (P = .025) in the volume of voiding was observed in cell-implanted rats as compared to sham injected rats. Histological analysis of the urethra implanted with myoblasts showed recovery of the atrophied muscular layer in comparison to sham control. Immunofluorescence analysis of the cell injected tissues confirmed the presence of human myoblasts in the regenerated area. CONCLUSION: This simplified method of in vivo testing can serve as a tool to test the efficacy of new therapies for treating SUI.

Transplantation of Autologous Ex Vivo Expanded Human Conjunctival Epithelial Cells for Treatment of Pterygia: A Prospective Open-label Single Arm Multicentric Clinical Trial.

PURPOSE: To establish the efficacy and safety of ex vivo cultured autologous human conjunctival epithelial cell (hCjEC) transplantation for treatment of pterygia. METHODS: Twenty-five patients with pterygia were recruited at different centers across the country. Autologous hCjEC grafts were prepared from conjunctival biopsy specimens excised from the healthy eye and cultured ex vivo on human amniotic membrane mounted on inserts using a unique mounting device. The hCjEC grafts were then transported in an in-house designed transport container for transplantation. Post-surgery, the patients were followed up on days 1, 7, 14, 30, 90, and 180 as per the approved study protocol. Clinical outcomes were assessed by slit lamp examination, visual acuity, imprint cytology, fluorescein/rose bengal staining, Schirmer's test, and photographic evaluation three and 6 months post-transplantation. RESULTS: Two patients were lost to follow-up and final analysis included 23 cases. No recurrence of pterygium was observed in 18 (78.3%) patients; all of these eyes showed a smooth conjunctival surface without epithelial defects. Recurrence was observed in 5 (21.7%) patients at 3 months post-treatment. No conjunctival inflammation, secondary infections or other complications were reported. Adequate goblet cells were present in 19 (82.6%) patients at the site of transplantation. CONCLUSION: We have, for the 1(st) time, standardized a protocol for preparing autologous hCjEC grafts that can be safely transported to multiple centers across the country for transplantation. The clinical outcome was satisfactory for treating pterygia.

Status of stem cell based clinical trials in the treatment for diabetes.

Rapidly increasing number of diabetic patients across the world is a great challenge to the current therapeutic approach. Although the traditional method of rendering exogenous insulin is an established method of treatment, it is not sufficient and often causes lethal hypoglycemia. There is also a good amount of success with whole organ transplantation or Islet cells' transplantation. But this technique is limited with regards the availability of donors. Currently, many clinicians and researchers are involved in clinical studies using various different stem cells from embryonic as well as adult sources for the treatment of diabetes. In this review we have tried to discuss the results of various clinical trials using stem cells. We have also tried to look at various stem cell types and the routes of injections that are currently being followed world wide.

In vitro and in vivo evaluation of (L)-lactide/ε-caprolactone copolymer scaffold to support myoblast growth and differentiation.

Skeletal muscle regeneration involves the activation of satellite cells to myoblasts, followed by their proliferation and fusion to form multinucleated myotubes and myofibers. The potential of in vitro proliferated myoblasts to treat various diseases and tissue defects can be exploited using tissue-engineering principles. With an aim to develop a biocompatible and biodegradable scaffold that supports myoblast growth and differentiation, we have developed a porous sponge with 70/30 L-lactide/ε-caprolactone copolymer (PLC) using a phase inversion combined with particulate leaching method. Degradation studies indicated that the sponge retained its structural integrity for 5 months in vitro and had undergone complete biodegradation within 9 months in vivo. The sponge supported human myoblasts attachment and its proliferation. Myoblasts seeded on the PLC sponge differentiated and fused in vitro to form myotubes expressing myosin heavy chain. Histological and molecular analyses of the PLC scaffolds seeded with green fluorescent protein-labeled human myoblasts and implanted ectopically under the skin in SCID mice demonstrated the presence of multinucleated myotubes expressing human muscle-specific markers. Our results suggest that PLC sponges loaded with myoblasts can be used for skeletal muscle engineering or for inducing muscle repair.