Stress management in composite biopolymer networks

TL;DR

This study investigates how collagen fibers embedded in a hyaluronan matrix influence tissue mechanics, revealing synergistic effects that enhance stiffness and strain response, with implications for biological understanding and material design.

Contribution

It demonstrates the dual role of the polysaccharide matrix in internal stress generation and elastic reinforcement, advancing knowledge of tissue mechanics and synthetic material design.

Findings

Networks exhibit increased stiffness and delayed strain-stiffening.

Polysaccharide matrix induces internal stresses affecting mechanics.

Synergistic effects enable tunable strain sensitivity.

Abstract

Living tissues show an extraordinary adaptiveness to strain, which is crucial for their proper biological functioning. The physical origin of this mechanical behaviour has been widely investigated using reconstituted networks of collagen fibres, the principal load-bearing component of tissues. However, collagen fibres in tissues are embedded in a soft hydrated polysaccharide matrix which generates substantial internal stresses whose effect on tissue mechanics is unknown. Here, by combining mechanical measurements and computer simulations, we show that networks composed of collagen fibres and a hyaluronan matrix exhibit synergistic mechanics characterized by an enhanced stiffness and delayed strain-stiffening. We demonstrate that the polysaccharide matrix has a dual effect on the composite response involving both internal stress and elastic reinforcement. Our findings elucidate how tissues can tune their strain-sensitivity over a wide range and provide a novel design principle for synthetic materials with programmable mechanical properties.