A versatile framework for simulating the dynamic mechanical structure of cytoskeletal networks

TL;DR

This paper presents a coarse-grained simulation framework for cytoskeletal networks that accurately models their mechanical and dynamic behaviors, aiding in understanding cellular mechanics and designing biomaterials.

Contribution

The authors introduce a versatile, biologically relevant simulation model for actin-myosin networks that captures experimental trends and predicts viscoelastic and contractile properties.

Findings

Model accurately reproduces filament fluctuation statistics

Simulates mechanical responses to shear and motor activity

Predicts viscoelastic scaling and network contractility

Abstract

Computer simulations can aid in understanding how collective materials properties emerge from interactions between simple constituents. Here, we introduce a coarse-grained model that enables simulation of networks of actin filaments, myosin motors, and crosslinking proteins at biologically relevant time and length scales. We demonstrate that the model qualitatively and quantitatively captures a suite of trends observed experimentally, including the statistics of filament fluctuations, mechanical responses to shear, motor motilities, and network rearrangements. We use the simulation to predict the viscoelastic scaling behavior of crosslinked actin networks, characterize the trajectories of actin in a myosin motility assay, and develop order parameters to measure contractility of a simulated actin network. The model can thus serve as a platform for interpretation and design of cytoskeletal materials experiments, as well as for further development of simulations incorporating active elements.