Figure 3.

In vitro capillary tube formation assay. Capillary tube formation was induced by that addition of Matrigel after 6 d. a) EPCs cultured on flat substrates (i) formed a low density of unorganized capillary tubes while EPCs cultured on nanotopographic substrates (ii) formed extensive networks of organized structures, b,c) which had longer average lengths when compared to EPCs cultured on flat substrates (*** p < 0.001). Furthermore, the vast majority of EPCs on nanotopographic substrates were recruited into capillary tubes, which was far greater than that of EPCs on flat substrates. Image was rotated demonstrate the length of observed tubules. The direction of the linear nanotopographic features is indicated by the arrow. Scale bars are 200 µm..