Persistence-driven durotaxis: Generic, directed motility in rigidity gradients

TL;DR

This paper demonstrates that cell motility on substrates with varying stiffness results in a net movement toward stiffer areas due to increased persistence time, modeled through simple stochastic models and simulations.

Contribution

It introduces a generic, persistence-driven mechanism for directed cell movement in stiffness gradients, emphasizing a kinesis rather than taxis.

Findings

Cells exhibit higher persistence on stiffer substrates.

Directed movement up stiffness gradients is explained by persistence-driven durokinesis.

The model captures the balance between diffusive spreading and wave-like propagation.

Abstract

Cells move differently on substrates with different elasticities. In particular, the persistence time of their motion is higher on stiffer substrates. We show that this behavior will result in a net transport of cells directed up a soft-to-stiff gradient. Using simple random walk models with controlled persistence and stochastic simulations, we characterize this propensity to move in terms of the durotactic index measured in experiments. A one-dimensional model captures the essential features of this motion and highlights the competition between diffusive spreading and linear, wavelike propagation. Since the directed motion is rooted in a non-directional change in the behavior of individual cells, the motility is a kinesis rather than a taxis. Persistence-driven durokinesis is generic and may be of use in the design of instructive environments for cells and other motile, mechanosensitive objects.