A microstructurally informed model for the mechanical response of three-dimensional actin networks

TL;DR

This paper introduces a microstructurally informed model for the linear elastic behavior of 3D actin networks, capturing anisotropic properties and density-dependent scaling, with parameters calibrated via finite element simulations.

Contribution

The authors develop a novel class of models that incorporate microstructural details and anisotropy, calibrated with finite element models for accurate mechanical predictions.

Findings

Model accurately estimates network mechanics across densities and anisotropies

Mechanical properties scale with filament density following a power law

Model parameters can be determined from finite element simulations

Abstract

We propose a class of microstructurally informed models for the linear elastic mechanical behavior of cross-linked polymer networks such as the actin cytoskeleton. Salient features of the models include the possibility to represent anisotropic mechanical behavior resulting from anisotropic filament distributions, and a power-law scaling of the mechanical properties with the filament density. Mechanical models within the class are parameterized by seven different constants. We demonstrate a procedure for determining these constants using finite element models of three-dimensional actin networks. Actin filaments and cross-links were modeled as elastic rods, and the networks were constructed at physiological volume fractions and at the scale of an image voxel. We show the performance of the model in estimating the mechanical behavior of the networks over a wide range of filament densities and degrees of anisotropy.