Figure 2.

PoT printing provides independent control of micropatterned chemistry and microtopography to direct cell alignment on surfaces. (a) Example of 20 µm wide, 20 µm spaced, and 5 µm tall micro-ridges in PDMS uniformly coated with FN (green). The actin cytoskeleton (red) of CMs cultured on this surface aligns with the topography. 20 µm wide FN lines were also PoT printed orthogonal to micro-ridges that were (c) 15.5 µm, (d) 26 µm, and (e) 33 µm tall. Note that CMs follow the FN lines that conform to the top, bottom and sides of the ridges. (f–j) Top view of the surfaces in (a–e) with CMs additionally stained for nuclei (blue). (k–o) Cross-sections of the areas highlighted by dashed lines in (f–j). (p–t) Single ridges from the cross-sections in (k–o) show that the CMs are able to conform around the topography, even for 33 um tall micro-ridges. (u–y) Histograms of actin orientation angles show CMs are aligned along the topography on (u) FN adsorbed micro-ridge surfaces but follow the orthogonal PoT printed FN lines (v) on 5 um tall micro-ridges. (w) At the 15.5 µm height actin orientation starts to become bimodal, with CMs in the trenches showing some alignment to the micro-ridges. At the taller (x) 26 µm and (y) 33 µm heights CMs show increased actin alignment to the micro-ridges. Images are representative of n=3 samples for each depth. Histograms (u–y) are based on the actin alignment of the images in (f–j).