Modulating the living cell dynamics by surface functionalization*

During various physiological processes, such as morphogenesis, wound healing, and cancer invasion, collective cell migration occurs in a coordinated manner involving mechanical force generation. The forces balance with the cell-cell junctions and cell-substrate adhesion. By modulating cell-substrate adhesion, the collective migration of the cells can be tuned. Here, we vary the cell-substrate adhesion by surface functionalizing the substrate. We impose topological defects using a ridged topographical substrate coated with a negatively charged molecule. In this condition, fibroblast cells align azimuthally following the ridges. However, in the case of the positively charged ridged substrate, the cells change shape and become more isotropic. Moreover, the cell dynamics reveals different degree of collective migration leading the cells towards the topological defects with much higher average velocity on the positively charged surface than on the negatively charged one, due to the weaker cell-substrate adhesion. This work aims at elucidating the relation between adhesion and collective migration, while also providing a useful platform to tune cell migration.