Rostislav Boltyanskiy

A living cell is a complex soft matter system far from equilibrium. While it consists of components with definite mechanical properties such as stiffness, viscosity, and surface tension, the mechanics of a cell as a whole are more elusive. We explore cell mechanics by stretching single fibroblast cells and simultaneously measuring their traction stresses. Upon stretch there is a sudden, drastic increase in traction stresses, often followed by a relaxation over a time scale of ~1min. Upon release of stretch, traction stresses initially drop and often recover on a similar time scale of ~1min. We propose a minimally active linear viscoelastic model that captures the main features of cell response to stretch. The response we observe is also consistent with a biological model of tensional buffering. We propose that cell behavior in response to a mechanical perturbation, such as stretch, consists of crosstalk between these two models.