ABSTRACT

The topic of this chapter has obviously been inspired by heated debates in society about the ethics of using leftover in-vitro fertilization (IVF) embryos for derivation of embryonic stem (ES) cell lines. ES cells, first derived in 1981 by Evans and Kaufman,1 have been studied extensively as a model of development and differentiation. Isolation of human ES (hES) cells from leftover IVF embryos in 19982 boosted the research in this field, leading to great hopes for approaching the era of cell therapies. ES cells, the progeny of the inner cell mass (ICM) of a blastocyst, remain pluripotent, maintain normal karyotype through multiple passages in culture and can differentiate into derivatives of all three germ layers in vitro and in vivo, making teratomas in laboratory animals.3-5

Among their differentiation derivatives that can be produced in vitro are such sought-after cells as cardiomyocytes, neurons, oligodendrocytes, retinal pigment epithelium, and insulin-producing cells.4,6-11

Such cells and tissues, if robustly produced from ES cells, would satisfy an unmet medical need for tissue and organ repair and could be generated to decrease the risk of immune rejection either through banking a variety of genetically diverse cell lines or via patientspecific nuclear transfer technology.