A Photoactivatable Nanopatterned Substrate for Analyzing Collective Cell Migration with Precisely Tuned Cell-Extracellular Matrix Ligand Interactions
Figure 4
Cell migration behavior before and after release from geometrical confinement.
(A) Schematic representations of the procedure for inducing cell migration on the photoactivatable homogenous and nanopatterned surfaces. The entire surface is initially non-cell-adhesive, and a 150-μm circular cell-adhesive spot is generated by the first irradiation. Cells are allowed to attach to the spot for 1 hour, and the unattached cells are removed by a medium exchange. The cells are further cultured for 8 hours to make a confluent circular cell cluster (B, F). The migration of the cells is induced by secondary irradiation through another photomask, which allows the selective irradiation of the surrounding regions (not over the patterned cells). The blue and yellow colors represent non-cell-adhesive and cell-adhesive surfaces, respectively. (B-I) Phase contrast images of the cells (B, F) before and (C, G) 3 hours, (D, H) 6 hours, and (E, I) 9 hours after the secondary irradiation on (B-E) the homogenous and (F-I) the nanopatterned gold substrates picked up from the supplemental movies (Movie S1, S2). The cells in the periphery of the images are nonspecifically attached cells or those have migrated from neighboring circles. The scale bar represents 100 μm.