Heralding the Dawn of Cultured Adult Stem Cell Transplantation

Abstract

Over the last few years, research on stem cells has received much public attention both for its extraordinary potential and for the associated social, legal and public issues. One of the fundamental questions in developmental biology is: how does a single cell - the fertilized cell give rise to a complex, multicellular organism and what are the factors involved during this remarkable development? With that began the quest to define stem cells, identify and isolate the embryonic, fetal and adult stem cells. Then came the question of whether these stem cells derived from various sources can be used to determine the pharmacokinetics of drugs and toxins; and ultimately be used to replace cells in diseased tissues. These questions were answered by, series of experiments on animals followed by clinical trials using cultured adult stem cells, since the latter evoke the least debate on the ethical and legal fronts. Apart from the clinical use of hematopoietic stem cells, the other adult stem cells that have been tested and put to clinical use include: myoblasts for cardiac and skeletal muscle loss or degeneration; cultured beta cells for diabetes mellitus, and cultured limbal epithelial cells for reconstruction of ocular surface in limbal stem cell deficiency. This review briefly describes the concept of stem cells, the regulatory mechanisms that govern them, with special emphasis on stem cells in epithelial tissues and the technique of culturing limbal stem cells that has been developed at our institute.