Plasticity in passive cell mechanics

• A visco-elasto-plastic model is presented to reproduce passive cell mechanics.
• The plastic stretch is driven by the dissipated energy at cell's microstructure.
• Thermodynamical restrictions in non-linear elasticity are abided.
• The theoretical predictions are compared with the results of optical stretching tests.

A sufficiently large load applied to a living cell for a sufficiently long time produces a deformation which is not entirely recoverable by passive mechanisms. This kind of plastic behavior is well documented by experiments but it is still seldom investigated in terms of mechanical theories. Here we discuss a finite visco-elasto-plastic model where the rest elongation of the cell evolves in time as a function of the dissipated energy at a microstructural level. The theoretical predictions of the proposed model reproduce, also in quantitative terms, the passive mechanics of optically stretched cells.