What is Regenerative Medicine?Regenerative medicine is a new and developing field that aims to restore function in diseased or aged tissues through either revitalizing existing cells, or the transplantation of new cells. Revitalization could occur through the addition of powerful growth factors to the body, or modulating the immune system in a way that enhances cell survival and function.
Stem cells are of great interest to regenerative medicine. They lie deep within most tissues of the adult body, but are often difficult to manipulate or expand outside the body. Stem cells in the bone marrow are responsible for blood production and play a major role our immune defense system. Stem cells may lie at the heart of some cancers and their biology may lead to interesting new approaches to reducing tumor growth. Stem cells also reside in the adult heart and can be manipulated and grown outside the body - then transplanted back into the same patient. Embryonic stem cells can be isolated from human embryos (hES cells) and expanded to enormous numbers in the culture dish while remaining pluripotent - capable of generating all tissues of the human body.
Very recently, stem cells from the adult human body have been reprogrammed back to an embryonic stem cell state. These induced pluripotent stem (iPS) cells are important for regenerative medicine as they can be derived from a single patient, turned into any tissue of the body, and then used as a source of autologous cells for repair - thus avoiding immune rejection issues.
Furthermore, the use of iPS cells is not burdened with the ethical issues associated with the collection and destruction of human embryos. Finally, iPS cells derived from patients with specific diseases may be used as novel and important models of human disorders.