Minimal model for the inelastic mechanics of biopolymer networks and cells.

We explore the mechanism behind the ambiguous nonlinear mechanical response of biopolymer networks and cells. Our theoretical analysis is based on the inelastic glassy wormlike chain model (iGWLC), which accounts for simultaneous softening and stiffening in terms of two antagonistic mechanisms: viscoelastic stress stiffening caused by polymer stretching, and inelastic fluidization caused by bond breaking. On this basis, we derive a set of simple schematic constitutive equations that faithfully reproduce the rich inelastic phenomenology of biopolymer networks and cells.