Electrochemiluminescence Imaging of Cellular Contact Guidance on Microfabricated Substrates.

Cells tend to align and move by following anisotropic topographical cues, namely the phenomenon known as contact guidance-an essential step in cell alignment, adhesion, and migration. The effect of topographical cues on individual cells has been investigated extensively, but that on cell aggregates still remains to be fully understood. Considering the high surface sensitivity of electrochemiluminescence (ECL) microscopy, it was used in this work to explore the impact of surface topography on cell behaviors. First, we studied the variations of cell-matrix adhesions of cells cultured on different topographical features. Both fibroblast-like and epithelial cells plated on microgrooved electrodes exhibited obvious contact guidance behavior. Then, the effect of surface topography on cellular collective migration was investigated. Topographic cues would be a barrier for cell migration if the orientation of microgrooves was perpendicular to the direction of migration; otherwise, it would be a helper. Finally, it was found that relaxation of cytoskeleton contractility or reduction in adhesion density could weaken the directed migration of leading cells, because the alteration of migration directionality was retarded. In contrast, such interactions were lost on the contact guidance response of follower cells, as they still aligned by following the topographic cues.