Non-linear stress relaxation of transient-crosslinked biopolymer networks

TL;DR

This paper presents a theoretical model explaining the long-term stress relaxation in living cell cytoskeletons, accounting for transient crosslinkers and internal stresses, aligning well with experimental data.

Contribution

The study introduces a mode-dependent mobility model to describe stress relaxation in prestressed transient biopolymer networks, advancing understanding of cellular mechanics.

Findings

Model agrees with experimental data on cytoskeletal networks

Explains slow stress relaxation in cells

Highlights role of transient crosslinkers and internal stress

Abstract

A long standing puzzle in the rheology of living cells is the origin of the experimentally observed long time 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.