Stem-Cell Responses to Surface Nanotopographies

Stem cells have attracted great attention in recent years due to their promise in regenerative medicine. Knowledge regarding the maintenance of stem cells during cell expansion and directional differentiation of stem cells into a specific lineage is of great importance to clinical applications of stem-cell-based therapies. An important strategy of regenerative medicine is to restore the in vivo stem-cell niche environment, including biochemical cues, topographic cues, and mechanical induction. More and more studies indicate that surface nanotopography exerts significant impacts on directing stem-cell differentiation. In this chapter, we will introduce the responses of stem cells to physical nanotopography, such as protrusion, pores, grooves/ridges, and fibers, containing topographic features smaller than 1000 nm. The most obvious effect of surface nanotopography is the alteration to cell adhesion and cytoskeleton formation. It is suggested that the changes in the formation of F-actin may influence nucleus morphology, which in turn affects the cellular gene-expression profile. Although the interaction between stem cells and nanotopography remains less explored, we believe that with more knowledge regarding stem-cell-nanotopology interactions, the researchers can design better strategies combining biochemical and topographic cues for tissue engineering and regenerative medicine.