Integrins Direct Cell Adhesion in a Substrate-Dependent Manner

The relationship between substrate properties and cell behavior is complex, including roles for both mechanics and biochemistry. Here we investigate the role of viscous dissipation on cell adhesion behaviors, using polymer films of tunable lateral mobility. We find that fibroblasts selectively use α v β 3 and α 5 β 1 integrin receptors to control their spreading area and polarization on low and high mobility films, respectively. In addition, the dynamics of cell spreading and polarization are well described by a semi-empirical sigmoidal relationship. Analysis of cell dynamic behavior reveals that spreading dynamics are controlled by the availability of integrins, whereas the polarization dynamics are controlled by intracellular signaling. The result that cells preferentially use specific integrin receptors in response to substrate mechanical properties has broad implications for processes in dynamic environments such as wound healing and cancer metastasis.