Human embryonic stem cells for tissue engineering

Human embryonic stem cells (HESCs) are characterized by their ability to self-renew and capacity to differentiate into almost every cell type. As a result, they have enormous potential for use in tissue engineering and transplantation therapy. If these cells can be induced to differentiate into a particular cell type, they may provide an almost unlimited source of cells for transplantation for treating certain diseases where normal cell function is impaired. The challenge lies in the development of techniques to induce differentiation into a specific cell type, to enrich for that population, and to isolate it. It is essential that the starting material, the undifferentiated embryonic stem cell line, is growing under optimal conditions that preserve its pluripotent potential and maintain a stable karyotype. This review will discuss methods for the growth, maintenance, and spontaneous differentiation of HESCs and methods to genetically manipulate them.