Nonlinear stress relaxation of transiently crosslinked biopolymer networks

A long-standing puzzle in the rheology of living cells is the origin of the experimentally observed longtime stress relaxation. The mechanics of the cell is largely dictated by the cytoskeleton, which is a biopolymer network consisting of transient crosslinkers, allowing for stress relaxation over time. Moreover, these networks are internally stressed due to the presence of molecular motors. In this work we propose a theoretical model that uses a mode-dependent mobility to describe the stress relaxation of such prestressed transient networks. Our theoretical predictions agree favorably with experimental data of reconstituted cytoskeletal networks and may provide an explanation for the slow stress relaxation observed in cells.

Automated summary

The mechanics of living cells are largely determined by the cytoskeleton, a biopolymer network with transient crosslinkers allowing for stress relaxation over time. Additionally, internal stress in these networks is caused by the presence of molecular motors. A theoretical model using mode-dependent mobility was proposed to explain the stress relaxation in such prestressed transient networks, showing good agreement with experimental data.