oa Editorial [Hot Topic: Stem Cells (Guest Editor: Anand Srivastava)]

In last ten years, research field in stem cells has garnered a lot of attention from researchers and clinicians due to several reasons. Studies on human embryonic stem (hES) cells have potential to unfold the information about the complex events that occur during human development. The most important potential application of human stem cells is the generation of cells and tissues that could be used for cell-based therapies. Stem cells differentiated into specific cell types, offer the possibility of a renewable source of replacement cells and tissues to treat a number of diseases including Alzheimer's diseases, spinal cord injury, stroke, burns, heart diseases, diabetes, osteoarthritis, and rheumatoid arthritis to name a few. Furthermore, some of the most serious medical conditions, such as cancer and birth defects, are due to abnormal cell division and differentiation. Studies of stem cells offer a more complete understanding of the genetic and molecular controls of these processes that may yield information about how such diseases arise and may reveal new strategies for therapies. Human stem cells could also be used to test new drugs. Other kinds of cell lines are already being used in this way. The availability of pluripotent stem cells allow drug testing in a wider range of cell types. The present issue of “Stem Cells” covers the potential use of stem cells in various pathological conditions in clinical setup. Dhawan et al. have descried the current understanding of stem cell organization and that of Cancer Stem Cells (CSC) within the colonic epithelium and have discussed the potential role of CSCs in the development and/or progression of CSC and have proposed them as targets for therapeutic interventions. Didwania et al. have discussed about the production of red blood cells from human embryonic stem cell and have proposed the production of red blood cell using bioreactor. Authors also have presented a mathematical model to describe the dynamics of expansion, and maintenance of homeostasis in the bioreactor. They have described cell expansion in the artificial hematopoietic stem cell niche in order to design and optimize a scaled-up red blood cell production in bioreactor. Whereas Dr. Pillai has discussed the potential strategies for using stem cells in clinical set up including stem cell sources, bio-scaffolds, mechanical stimulation, genetic modification and co-culture techniques to direct ocular-lineage differentiation of stem cells for complete or partial eye regeneration and research. This article discusses the broad introduction to the stem cell-mediated correction of eye ailments and provides extensive references for interested readers. This paper also looks into the different aspects of using stem cells for drug development for treating eye ailments. The main challenge of the stem cell transplant is the immunorejection of stem cell by the host tissue. The article written by Thompson et al summarizes various ways to overcome this potential problem. They discuss the challenges faced to in vitro development of a bona fide ESC-derived hematopoietic stem cells and their differentiation fate in vivo, and provide suggestions to predict the immunogenicity of specific ESC-derived hematopoietic populations before transplantation that could be used to prevent their rejection after transplantation into an adult host. The article by Talbot summarizes the possible use of stem cell biology to study the toxic effect of chemicals on the cells. They proposes that In vitro models are especially attractive in predictive toxicology as they can greatly reduce assay costs and animal usage while identifying those chemicals that may require further in vivo evaluation. This review covers various toxicological studies and strategies extensively those have been used with embryonic stem cells during last five years and possible directions that could lead to improvements in the development of predictive assays in future. Susana Inoges et al. have discussed the potential of autologous or allogeneic stem cell transplantation in treatment of B-cell malignancy including multiple myeloma and follicular lymphoma. They have discussed the clinical trials that combined stem cell transplant procedures with idiotypic vaccination, which also includes some of his experience with the transplant and his original data, as well as overall evaluation of this field of stem cell transplantation. Finally, he concluded that toxicity-burdened stem cell transplantation and virtually innocuous idiotypic vaccination might well offer a sound curative opportunity in incurable B-cell malignancies. Present issue discusses in detail about the development of stem cell field, its potential uses and future directions to upcoming clinician and researchers.