Mouse embryonic stem cells cultured under serum- and feeder-free conditions maintain their self-renewal capacity on hydroxyapatite

New tissue engineering techniques based on embryonic stem (ES) cells and artificial scaffolds are required for regenerative medicine. Because artificial scaffolds can regulate the differentiation states of ES cells, compatibility between the cells and artificial scaffolds is important. To our knowledge, this study is the first report showing that mouse ES (mES) cells can be maintained in undifferentiated state on hydroxyapatite coated with gelatin. In contrast to previous studies, our culture medium was serum-free and included a GSK-3 inhibitor. Under these conditions, mES colony morphology was similar to that of an undifferentiated state; mES cells expressed the pluripotent-specific factors Oct-3/4 and Nanog, and they maintained the ability to differentiate into the three germ layers. Moreover, a GSK-3 inhibitor blocked the expression of integrin subunits that bind to laminin which are known to induce the differentiation of mES cells. These findings indicate that mES cells can be cultured under serum- and feeder-free conditions and maintained in an undifferentiated state on a composite with hydroxyapatite and that this composite can be used to control the differentiation of stem cells.