A predictive microstructure-based approach for the anisotropic damage, residual stretches and hysteresis in biodegradable sutures

TL;DR

This paper introduces a comprehensive predictive model for biodegradable polymers used in biomedical sutures, capturing anisotropic damage, residual stretches, and hysteresis by linking microscopic network behavior to macroscopic mechanical responses.

Contribution

The model uniquely incorporates microscopic damage mechanisms and network transitions to predict complex mechanical behaviors of biodegradable sutures, aiding material design.

Findings

Successfully predicts cyclic behavior of poliglecaprone sutures

Captures anisotropic damage and hysteresis effects

Extensible to various biomedical materials

Abstract

We propose a predictive model for the mechanical behavior of biodegradable polymers of interest for biomedical applications. Starting from a detailed description of the network behavior of the copolymer material, taking care of bonds breaking and recrosslinking effects, folded-unfolded transitions and network topological constraints, we deduce a macroscopic law for the complex mechanical behavior of many biomedical materials with a particular focus on absorbable suture threads and a perspective to new material design. A crucial novelty of the model is the careful description of the observed microscopic anisotropic damage induced by the deformation, here described based on the classical microsphere integration approach. The resulting energy, characterized by a few number of material parameters, with physically clear interpretation, is successfully adopted to predict our cyclic experiments on poliglecaprone sutures with anisotropic damage, permanent stretch and internal hysteresis. By also studying other suture materials behavior we show that the predictivity properties of the model can be extended also to materials with a different mechanical response and thus also possibly applied for the design of new, high-performance biomedical materials.