Interaction of a migrating cell monolayer with a flexible fiber

TL;DR

This study models how migrating cell monolayers interact with elastic fibers, revealing that tissue forces involve inertia and viscosity, and demonstrating a minimal active-fluid model that captures these interactions.

Contribution

The paper introduces a minimal active-fluid model that accurately describes tissue-elastic interactions, highlighting the roles of inertia and viscous stresses in force transmission.

Findings

Cells perform fixed mechanical work on fibers before stopping.

The model predicts the fiber bending and recoil behavior.

Interaction forces depend on tissue mechanics and fiber properties.

Abstract

Mechanical forces influence the development and behavior of biological tissues. In many situations these forces are exerted or resisted by elastic compliant structures such as the own-tissue cellular matrix or other surrounding tissues. This kind of tissue-elastic body interactions are also at the core of many state-of-the-art {\it in situ} force measurement techniques employed in biophysics. This creates the need to model tissue interaction with the surrounding elastic bodies that exert these forces, raising the question: which are the minimum ingredients needed to describe such interactions? We conduct experiments where migrating cell monolayers push on carbon fibers as a model problem. Although the migrating tissue is able to bend the fiber for some time, it eventually recoils before coming to a stop. This stop occurs when cells have performed a fixed mechanical work on the fiber, regardless of its stiffness. Based on these observations we develop a minimal active-fluid model that reproduces the experiments and predicts quantitatively relevant features of the system. This minimal model points out the essential ingredients needed to describe tissue-elastic solid interactions: an effective inertia and viscous stresses.