Current Stem Cell Research & Therapy - Volume 12, Issue 8, 2017

Background: Adult mesenchymal stem cells (MSCs) were first isolated from bone marrow by Friedenstein in 1976. These cells were clonogenic, non-haematopoietic, and able to replicate extensively in vitro. The fields of regenerative medicine and tissue engineering have grown dramatically since their inception. In the decades since, MSCs have been identified from mesoderm-, endoderm- and ectoderm-derived tissues. In light of our ageing population, the need for effective cell-based therapies for tissue repair and regeneration is ever-expanding. Objectives: The purpose of this systematic review was to summarise evidence from the most recent studies outlining different sources of adult MSCs and their suitability in musculoskeletal applications. Methods: Online published articles were searched for using the PubMed/MEDLINE and Ovid databases, and relevant articles fulfilling the pre-defined eligibility criteria were analysed. Results: To date, MSCs have been isolated from a number of adult tissues, including trabecular bone, adipose tissue, bone marrow, synovium, dermis, periodontal ligament, dental pulp, bursa and the umbilical cord. Bone marrow MSCs are currently considered the gold standard, with which newly discovered sources are compared on the basis of their renewal capabilities and multipotency. Furthermore, MSCs have been successful in the regeneration of osteonecrosis, osteoarthritis, bony defects, fracture remodeling and so on. Conclusion: Unfortunately, significant hurdles remain and will need to be overcome before tissue engineering using MSCs becomes routine in clinical practice. Thus, further research and understanding are required into the safe and effective sourcing and application of mesenchymal stem cells in musculoskeletal applications.

Background: Diabetes mellitus, the widely prevalent disease of pancreas, is a metabolic disorder caused by autoimmune destruction of β cells or insulin insufficiency or insulin resistance. Replacement of damaged β cells by cell therapy can mitigate the condition and re-establish normal metabolic control. This has opened up new horizons for research, such as stem cells, cellular reprogramming and β cell regeneration. Objective: The goal of the study was to summarize the available literature on the use of stem cells for the regeneration of pancreatic β cells and treatment of diabetes mellitus. Results and Conclusion: Stem cells are exceptional having the potential to self renew and differentiate in many lineages. Stem cells hold tremendous potential to regenerate β cells and treat diabetes mellitus but many milestones on the way are yet to be achieved. But researchers do believe that stem cells and regenerative medicines will be widely used in clinical practices and possibly new effective methodology would be designed for even cure, mitigate and reduce the social burden of diabetes mellitus.

Background: Despite optimal treatment, myocardial infarction (MI) remains a major cause of death worldwide. Stem cell transplantation, as a promising therapy hoping to improve myocardial function and generate new myocardium, has been intensely studied for treating MI. Objective: To summarize the recent advance of stem cell transplantation for treating MI in clinical trials and preclinical studies. Results: Several types of adult stem cells have been applied to clinical trials and exerted beneficial effects against MI. The therapeutic effects of these stem cells are varied, modest and mostly depend on paracrine function. Embryonic stem cells and induced pluripotent stem cells, as well as their derivative cells, bring a new dawn for cardiac regeneration although they have not been applied in patients due to safety concerns. Feasible solutions are required to stress the safety issue, and to improve the survival, engraftment, migration, differentiation and synchronization with recipient myocardium of transplanted stem cells. Conclusion: Stem cell transplantation for treating MI in clinical trials has achieved modest therapeutic effect. The hurdles limiting the stem cell function define the direction of further research.

Background: Embryonic stem cells are pluripotent, meaning they have the capacity to selfrenew and to differentiate into cells of the 3 germ layers. In 2006, Takahashi et al. reprogrammed somatic cells into stem cells using exogenetic gene expression. These new cells became known as induced pluripotent stem cells (iPSCs). Research continues to develop new tools and techniques in order to reprogram cells with higher output and quality, so that iPSCs can be used in modeling of human disorders, drug discovery and of course, regenerative medicine. Objective: After a brief overview of the basic characteristics of iPSCs, this article will cover the production and processing techniques of these cells, with a focus on new innovations, as well as their different uses and potential role in future research. Conclusion: Progress over the last few years regarding the efficient and safe ways to produce iPSCs has been tremendous. These cells might open doors regarding the future of precision medicine practices and research.

Background: Inflammatory bowel diseases (IBD), which include Crohn's disease and Ulcerative Colitis, are inflammatory autoimmune diseases which severely affect the quality of life. Till date, no long-lasting cure has been found for the disease and all the current treatment strategies are mainly focused on dampening the symptomatic inflammatory process that has certain side effects. In addition, a large number of patients remain refractory to conventional therapies. Mesenchymal stem cells (MSCs) can be looked upon as a biodrug to treat IBD owing to their immune-suppressive and regenerative capabilities. MSCs provide an advantage over the other widely used adult stem cells- hematopoietic stem cells in the aspects of lower side effects and enhanced tolerability. MSCs have had reasonable success thus far in clinical trials to treat IBD via systemic delivery as well as in local delivery (perianal Crohn's disease). Objective: In order to optimize and standardize, MSC based therapy for IBD, a better understanding of cellular and molecular mechanisms of the therapeutic activities of MSCs, is extremely mandatory. There has been a plethora of publications in the last decade which elucidates the biologic rationale that makes MSC a promising therapeutic tool for IBD. Recent studies have witnessed a replacement of hypotheses regarding the mechanism of MSCs in curing IBD. The present review summarizes all these discussions, the results of the trials carried out to date and the future prospects in this field. Conclusion: Based on the current development of MSC-based clinical trials and the ever-increasing rate of in-vitro studies, with a purpose to unveil the mechanism of curative approach of these cells, MSC based therapy for IBD can be expected to achieve clinical relevance in the near future.

Background: During the last two decades, a number of studies have been carried out on the application of regenerative medicine in the field of dermatology. Objective: The aim of this research was to critically review the application of regenerative medicine in the field of dermatology. The next aim was to look in depth to see whether regenerative medicine strategies have a place in the future of wound healing in a clinical setting. More specifically, to see if these strategies would apply for burns and non-healing diabetic wounds. Results: Billions of dollars have been spent worldwide on research in wound treatment and skin regeneration. Although a high number of clinical trials show promising results, there is still no commercially available treatment for use. In addition, the outcome data from the clinical trials, taking place throughout the world, are not published in a standardized manner. Standardization within clinical trials is required for: protocols, outcome, endpoint values, and length of follow-up. The lack of standardization makes it much more difficult to compare the data collected and the different types of treatment. Conclusion: Despite several promising results from research and early phase clinical studies, the treatment for wounds as well as skin regeneration is still considered as an unmet clinical need. However, in the past three years, more promising research has been approaching clinical trials; this could be the solution that clinicians have been waiting for. This is a multibillion dollar industry for which there should be enough incentive for researchers and industry to seek the solution.

Background: Fibroblasts are the common cells used in clinical regenerative medicine and dentistry. These cells are known to appear heterogeneous in vivo. Previous studies have only investigated the biological properties of these cell subpopulations in vitro. Despite sharing similarity in their spindle-shaped appearance, previous literatures revealed that they play distinguished functional and biological activities in the body. Objective: This paper highlights the similarities and differences among these cell subpopulations, particularly between intraoral fibroblasts (human periodontal ligament, gingival and oral mucosa fibroblasts) and dermal fibroblasts based on several factors including their morphology, growth and proliferation rate. Results: It could be suggested that each subpopulation of fibroblasts demonstrate different positionspecified gene signatures and responses towards extracellular signals. These dissimilarities are crucial to be taken into consideration to employ specific methodologies in stimulating these cells in vivo. Conclusion: A comparison of the characteristics of these cell subpopulations is desired for identifying appropriate cellular applications.