Figure 3.

Time-lapse phase-contrast images of NIH3T3 cells cultured on a patterned surface. a, Schematic diagram showing the full pattern design representing the pitch gradient. The distance between features varied between 1 and 10 μm, detailed dimensions are shown in Supplementary Fig. S5. The gradient was patterned on an area of 700 × 700 μm² with crater diameter and depth of 1000 nm and 350 nm, respectively. b, At 1hr most cells are able to attach to the surface and spread even on the 1~2 μm spacing patterned area. c–f, However, the cells tend to migrate towards regions with greater pitch between the nanocraters. One day after cell seeding, clear boundary lines define a cell repellent region.