SYNOPSIS
Pluripotent embryonic stem cells have the potential to differentiate to all fetal and adult cell types and might represent a useful cell source for tissue regeneration. Moreover, the applicable of an embryonic stem cell can be used not only to the tissue regenerative field but also to in vitro embryotoxicity field. The influences of biomaterials on human reproduction and development are still unclear. Their influences on the next or future generations are also unknown. Although many biomaterials have already been used, many people have concerns over them. Regarding long-term embryotoxicity associated with biomaterial exposure, even the presence or absence of risks is unclear. Spielmann et al. suggested that embryotoxicity could be estimated based on influences on ES cell differentiation. In 1997, Spielmann et al. proposed the first in vitro embryotoxicity test (EST) protocol using ES and 3T3 cells. The EST protocol has achieved global attention as an in vitro means to screen the embryotoxicity of chemical substances. The EST protocol should be further improved as a useful method of utilizing an embryonic stem cells.

Key words:ES cells, EST, embryotoxicity