Figure 4.

Staining for phalloidin and collagen IV of human MSCs cultured on OPF+ sheets with ridges, flat OPF+ sheets or glass. Human MSCs were grown for 7 days on OPF+ sheets containing ridges (A), on the flat side of the OPF+ sheet (B) or on glass (C), and then fixed, permeabilized, and stained with DAPI (blue) to visualize cell nuclei and phalloidin (green) for the actin cytoskeleton. On the ridged surface, multicellular clusters formed as indicated by multiple nuclei in a 3D spheroidal organization. On flat surfaces, cells attached and spread with a similar morphology.