Schematic representations of cell sheet migration.

<p>Representative renditions of cell sheet migration on (A-B) patterned and (C-D) flat silk film surfaces. (A) Cell sheet migration on patterned silk surfaces was compact in nature with leading border cells elongating in the parallel direction of the patterned feature edge. Migration rate was 2-fold higher in the parallel direction of the feature edge when compared to perpendicular movement direction as indicated by the vectors contained in yellow diamond. (B) Actin fibril (red), FA (green), and GTPase (orange) proteins were found to preferentially localize along the surface feature edges as indicated in purple coloring. (C) In contrast, cell sheet migration on flat silk film substrates was less compact with leading cells maintain a normal cuboidal morphology. Migration rate was similar in all directions as indicated by the vectors contained in the yellow circle. (D) Actin fibrils (red) and FAs (green) were found to primarily localize at the cellular basal periphery region with GTPase proteins (orange) localizing uniformly within the central region of the cell.