Embryonic stem cells

Preimplantation embryo development sets the stage for pluripotency Regenerative medicine has the potential to revolutionize health care by offering the promise of replacement cells, tissues, and organs to combat injury, disease, and aging. In an ideal setting, stem cell therapies would begin with a pluripotent cell that by definition is able to give rise to any cell formed in the embryo. Additionally this would most likely require that the stem cells could self-renew or were able to divide and give rise to either more pluripotent stem cells or progressively more differentiated cells under the control of extrinsic cues. Stem cells are biological cells found in multicellular organisms, that can mitotically divide and differentiate into specialized cell types and can self-renew to produce more stem cells. There are two broad types of stem cells: embryonic stem cells and adult stem cells. Embryonic stem cells originate from the inner cell mass of the preimplantation embryo and are considered pluripotent whereas in situ adult stem cells are considered multipotent. Embryonic stem cells (ESCs) possess characteristics that make them a potentially outstanding starting material for use in regenerative medicine. They are unique among cultured cells because they have an apparently limitless capacity to self-renew in vitro, as well as being pluripotent. Because of these extraordinary properties, ESCs have been an intense focus of research for more than 30 years.