International Journal of Advancements in Research & Technology, Volume 2, Issue 8, August-2013 ISSN 2278-7763 ODD PAGE Copyright © 2013 SciResPub. Stem cells: Frontier in disease research and development * Sandeep Kumar Vishwakarma 1 & 2 , Syed Ameer Basha Paspala 1 & 2 , Avinash Bardia 1 , Santosh K Tiwari 1 , Aleem A Khan* 1 & 2 1 Centre for Liver Research and Diagnostics, Deccan College of Medical Sciences, Kanchanbagh, Hyderabad-500058, Andhra Pradesh, India 2 PAN Research Foundation, Narayanguda, Hyderabad-500029, Andhra Pradesh, India . Email: aleem_a_khan@rediffmail.com ABSTRACT Understanding about the cellular therapeutic approaches has improved since last few years which has paved the way towards its therapeutic applications in the treatment of several incurable diseases. These approaches should be easily accessible to the patient’s as quickly as possible. Various landmark discoveries have done since last decades. However, suitable source, defined cell number and phenotype are still not clear that faint the strategy prior to application. Cellular reprogramming using somatic cell nuclear transfer (SCNT) provides a significant tool to overcome these hurdles by producing large number of functionally motivated cell phenotypes suitable for biopharmaceutical screening and creating stem cell lines as disease modules. Therefore, this review describes the current catalogue of human disease specific cells productions tools to overcome traditional sources and modules. Keywords : Embryonic stem cells; adult stem cells; SCNT; induced pluripotent stem cells; therapeutic potential Introduction One of the most exciting frontiers in stem cell biology and medicine is the potential use of stem cells for the treatment of various developmental or degenerative diseases for which there are no cures. Now days it is well known that most tis- sues in the body continuously generate new cells either to re- place the damaged/lost cells or to fulfill the increased demand [1]. The ability of a tissue to renew and repair itself depends on small group of cells called stem cells. These cells exist throughout life in close proximity with nurse cells which pro- vide them required growth factors and signals that helps to maintain the unique property of the stem cells-the capacity of self-renewal, long-term viability and multilineage potential [2]. Therefore, stem cell applications in regenerative medicine are being developed to regenerate tissues and repair failing or- gans. Research developments towards stem cell biology and regenerative medicine have proved the potential use of differ- ent types of stem cells in the treatment of various degenerative diseases such as Alzheimer disease, Parkinson’s disease, mus- cular dystrophy, brain trauma, spinal cord injury, myocardial infarction, critical limb ischemia, diabetes, stroke and cancers [3]. In clinical practice choosing suitable stem cell sources, use of advanced cell culture techniques, characterization, in vitro and in vivo behavior raises several controversies for using these cells [4]. Therefore, before transferring the experimental therapy into human, beneficial experimental data in suitable animal models should be provided for the treatment of partic- ular disease which should insure the proper cell integrity, via- bility and route of delivery. Since the stem cells research started, many sources have been used to isolate these types of cells in stem cell research and development. In a broad way according to the developmental status of the individuals, stem cells are classified into two ma- jor categories; embryonic stem cells and adult stem cells [5]. 1.1 Embryonic stem cells The successful conception of human embryonic stem (ES) cells in 1998 opened the door to an important new area of biomedi- cal research [6]. ES cells are unique biological entities that have the ability both to reproduce themselves endlessly and to give rise to all specialized cell types of the body. These cells are derived from the blastocyst-stage of early mammalian embryo and are characterized by their capacity for prolonged undiffe- rentiated proliferation in culture while maintaining the poten- tial to differentiate into derivatives of all three germ layers [6]. Several studies have been demonstrated in vitro spontaneous and directed differentiation systems for human ES cells into several lineages, including cardiac tissue [7], neuronal tissue *8+, β islet pancreatic cells [9], hematopoietic progenitors [10],