Abstract

Understanding of stem cell−surface interactions and, in particular, long-term maintenance of stem cell pluripotency on well-defined synthetic surfaces is crucial for fundamental research and biomedical applications of stem cells. Here, we show that synthetic surfaces possessing hierarchical micro-nano roughness (MN-surfaces) promote long-term self-renewal (>3 weeks) of mouse embryonic stem cells (mESCs) as monitored by the expression levels of the
pluripotency markers octamer-binding transcription factor 4 (Oct4), Nanog, and alkaline phosphatase.

On the contrary, culturing of mESCs on either smooth (S-) or nanorough polymer surfaces (N-surfaces) leads to their fast differentiation. Moreover, we show that regular passaging of mESCs on the hierarchical MN-polymer surface leads to an increased homogeneity and percentage of Oct4-positive stem cell colonies as compared to mESCs grown on fibroblast feeder cells.

Immunostaining revealed the absence of focal adhesion markers on all polymer substrates studied. However, only the MN-surfaces elicited the formation of actin-positive cell protrusions, indicating an alternative anchorage mechanism involved in the maintenance of mESC stemness.

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