Effect of culture substrate surface on formation of embryoid body

Mouse embryonic stem (ES) cells were cultured on a phospholipid polar groups-integrated surface (PC surface) and a conventional hydrophobic polystyrene surface called as bacterial culture grade Petri dish. ES cells were immediately aggregated on PC surface after seeding, and mono-aggregate (single embryoid body) was formed, and the size of embryoid body depended on the initial number of seeded ES cells. On polystyrene surface, the cells were locally aggregated, and the several aggregates were fused together. The formed embryoid body on PC surface highly expressed a transcription factor, CDH1, which was a marker of cell-cell adhesion rather than the embryoid body formed on polystyrene. On the other hand, the embryoid body formed on polystyrene highly expressed a transcription factor, Pax6, which was a marker of neural differentiation. It was concluded that the PC surface could induce the size-regulated embryoid body, and such embryoid body maintained the undifferentiated state.