Fig. 1.
Substrate stiffness modulates topographical contact guidance. (A) Schematics of matrix isotropy across a wide range of substrate stiffness (CDM: Cell derived matrix). (B) Snapshots of NIH 3T3 fibroblasts adhering, elongating and aligning on grooves of different stiffness. Scale bar, 20 μm. (C) Scheme depicting cell long axis a, short axis b and the angle between the long axis and the grooves θ. (D) Cell elongation and (E) cell alignment index as a function of the substrate stiffness. (F) MDA-MB-231 and T47D single cells spread on polyacrylamide gels with topographical grooves and ridges of increasing stiffness. Scale bar, 50 μm. (G) Cell elongation and (H) Alignment index as a function of substrate stiffness. Shadowed regions in (E) and (H) correspond to angles <30°. Data points (Mean ± SE) were fitted as an eye-guide. Statistical significance was assessed by Tukey's tests (D, G and H) and Kruskall-Wallis’ test (E). NIH 3T3 cells N ≥ 3 experiments per condition and n ≥ 50 cells per condition. MDA-MB-231 N ≥ 2 experiments per condition and n ≥ 58 cells per condition. T47D cells N ≥ 2 experiments per condition and n ≥ 22 cells per condition. See Tables S1–S3 for the exact number of cells and experiments.