FIGURE 3.

hMSC shape and cytoskeletal organization on topography 1018 and flat surfaces. (A) hMSCs cultured on a flat surface and a Topo1018 surface and stained with phalloidin to visualize F-actin (yellow) at 30 min, 2, 4, 12, and 24 time points. On a flat surface (top panel), transverse arcs and dorsal stress fibers are observed at 2 h. This replaces itself with thick ventral stress fibers after 4 h. On the Topo1018 surface (bottom panel), hMSCs are on top of the pillars and stress fibers are observed on the lamellipodia on the bottom of the topography at 4 h. After 12 h, cells settled between the pillars and sat between the topographies and displayed long and think stress fibers along their long axis. Scale bars represent 20 µM. Red arrows point the ventral stress fiber, blue arrows point dorsal stress fibers, and orange arrows point the transverse arcs. (B) Quantification of the cell area over time showed that after 4 h, the difference between the cell area between hMSCs on a flat surface and a Topo1018 surface becomes significant. (C) Quantification of cell aspect ratio suggests that on the Topo1018 surface there is a steady increase in cell elongation while on a flat surface it stabilized after 12 h (Error bars represent 95% confidence intervals, *p < 0.05, **p < 0.01, and ****p < 0.001) (*’s correspond to comparisons between different culture substrates in the same time point). For all experiments, N = 3.