Slow stress relaxation of transient-crosslinked biopolymer networks

It is well established that the unbinding of crosslinkers enables transient-crosslinked biopolymer networks to flow at long times. A recent experiment, however, shows that exerting prestress on such a network leads to near solid-like viscoelastic response. In this talk I will propose a microscopic theory for the rheology of transient networks under prestress. We show that the solid-like dynamics naturally appears as a result of the coupling between the strain-stiffening of semiflexible polymers and the transient nature of the crosslinkers. Our theory predicts the scaling behavior of shear modulus over the whole frequency regime and quantitatively fits the experimental data. This theory may also explain similar slow stress relaxation previously found in living cells.