Continuous release of bFGF from multilayer nanofilm to maintain undifferentiated human iPS cell cultures.

In most cases, induced pluripotent stem (iPS) cells must be maintained by replacing basic fibroblast growth factor (bFGF)-containing medium daily to inhibit spontaneous differentiation. However, complete inhibition of differentiation is difficult to achieve even with frequent replacement of medium because of bFGF instability. Here, we established a novel system for the sustained release of bFGF from a modified surface by using a nanofilm fabrication method.