An Attempt to Cell Recovery Factor in Cell Differentiation Culture with the Embryonic Stem Cell Test (EST)

Abstract

The experimental protocol of embryonic stem cell test (EST) using ES-D3 cells and 3T3 cells as an in vitro embryotoxicity test for biomaterials and medicine was established by H. Spielmann of Germany in 1997. In 1988, Imai proposed the cell recovery test as a variation of the cytotoxicity test. By exposing the material to cells, the transitory influence on recovery of the cell proliferation level is assessed. The cell recovery test was also developed similarly allowing the examination of not only recovery of cell proliferation but also recovery from chemical disruption of cell differentiation. After exposing both cells to NaF and SnF₂, used to prevent tooth decay, we compared the results of each culture in fresh medium with the findings obtained by the EST.
For "5-day recovery" and "7-day recovery", each value increased slightly. NaF and SnF₂ both showed "non-embryotoxicity" under all conditions. Based on these findings, no influence of cellular recovery was seem with demonstrated in NaF and SnF₂. These chemicals are both fluorine compounds, and the embryotoxicity level of SnF₂ is presumed to be slightly stronger than that of NaF. No influence of cellular recovery was demonstrated with NaF and SnF₂. Stronger embryotoxicity is a concern when the recovery culture shows that the toxicity level of a chemical remains constant; therefore, it is necessary to consider the utility of examining recovery from embryotoxicity.