Nonlinear Rheology in a Model Biological Tissue

TL;DR

This paper investigates the nonlinear rheological behavior of biological tissues using a particle-based model, revealing a transition from linear to shear-thinning flow driven by active and mechanical noise.

Contribution

It introduces a theoretical mean-field framework to explain nonlinear tissue flow, incorporating the effects of active processes and mechanical responses.

Findings

Identification of a crossover from linear to shear-thinning flow.

Development of a mean-field model capturing active and mechanical noise effects.

Evidence of non-linear rheology in biological tissue simulations.

Abstract

Mechanical signaling plays a key role in biological processes like embryo development and cancer growth. One prominent way to probe mechanical properties of tissues is to study their response to externally applied forces. Using a particle-based model featuring random apoptosis and environment-dependent division rates, we evidence a crossover from linear flow to a shear-thinning regime with increasing shear rate. To rationalize this non-linear flow we derive a theoretical mean-field scenario that accounts for the interplay of mechanical and active noise in local stresses. These noises are respectively generated by the elastic response of the cell matrix to cell rearrangements and by the internal activity.