Fig. 2: Morphological characterization of ECM protein patterns.
AFM topographs (height images) of (A) collagen I or (B) fibronectin patterns printed on glass with PDMS stamps having arrays of micropillars of different diameters. Top row shows topographs of 2 ×2 or 3 ×3 arrays of printed ECM protein patterns. Scale bar, 20 μm. Middle and bottom rows show the printed patterns at higher magnification and the height profile of the cross section of (A) collagen I or (B) fibronectin patterns. Scale bar, 2 μm. Images were acquired form at least 5 independent preparations. C Perpendicular diameters (d1, d2) and heights (h1, h2) of a printed ECM protein pattern (n = 39, 40, 53, 40, or 41 of printed collagen I patterns having diameters of 10 μm, 8 μm, 5 μm, 3 μm, or 2 μm; n = 44, 55, 41, 56, or 41 of printed fibronectin patterns having diameters of 10 μm, 8 μm, 5 μm, 3 μm, or 2 μm, respectively), used to quantify the average area, height, and roundness of the printed pattern. Scale bar, 2 µm. D Average area (top), height (middle), and roundness (bottom) derived from n number of collagen I or fibronectin patterns, which have been printed using PDMS micropillar of different diameters. Colored dots represent values of individual printed patterns, black dots mean values, and error bars standard deviations. Statistical analysis of the patterns is given in Supplementary Tables 1, 2.
