Embryonic stem cells from blastomeres maintaining embryo viability.

A wide variety of cell and tissue types that are sought in regenerative medicine can be generated from embryonic stem cells (ESCs), and currently two derivatives of human embryonic stem cells (hESCs) have entered human clinical trials. However, the ethical controversy surrounding this technology, which uses preimplantation human embryos to generate cell lines, is limiting research and the development of new therapies. Several new technologies such as induced pluripotent cells or parthenogenetically derived pluripotent cells hold great promise, but more research is needed before their derivatives can be proven to be safe and functional for use in human patients. The blastomere biopsy-based technique allows the derivation of human ESClines without sacrificing a human embryo and was shown to be robust and produce safe and functional derivatives of therapeutic value. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.