Universality in the morphology and mechanics of coarsening amyloid fibril networks

TL;DR

This study demonstrates a universal scaling law linking the morphology and mechanical properties of amyloid fibril networks, enabling predictive design of biomaterials based on peptide interactions.

Contribution

It introduces a universal time-scaling approach that connects peptide interaction parameters to network morphology and mechanics in amyloid fibrils.

Findings

Morphological quantities collapse onto master curves with a universal time scaling.

Shear modulus exhibits a non-monotonic dependence on time.

The model provides insights for designing amyloid networks with specific mechanical properties.

Abstract

Above a critical concentration a wide variety of peptides and proteins self-assemble into amyloid fibrils which entangle to form percolating networks called hydrogels. Such hydrogels have important applications as biomaterials and in nanotechnology, but their applicability often depends on their mechanical properties for which we currently have no predictive capability. Here we use a peptide model to simulate the formation of amyloid fibril networks, and couple these to elastic network theory to determine their mechanical properties. The simulations reveal that the time-dependence of morphological quantities characterizing the network length scales can be collapsed onto master curves by using a time scaling function that depends on the interaction parameter between the peptides. The same scaling function is used to unveil a universal, non-monotonic dependence of the shear modulus with time. The obtained insight into the structure-function relationship between the peptide building blocks, network morphology and network mechanical properties can aid experimentalists to design amyloid fibril networks with tailored mechanical properties.