Probing mechanical properties and failure mechanisms of fibrils of self-assembling peptides.

Self-assembling peptides (SAPs) are a promising class of biomaterials amenable to easy molecular design and functionalization. Despite their increasing usage in regenerative medicine, a detailed analysis of their biomechanics at the nanoscale level is still missing. In this work, we propose and validate, in all-atom dynamics, a coarse-grained model to elucidate strain distribution, failure mechanisms and biomechanical effects of functionalization of two SAPs when subjected to both axial stretching and bending forces. We highlight different failure mechanisms for fibril seeds and fibrils, as well as the negligible contribution of the chosen functional motif to the overall system rupture. This approach could lay the basis for the development of "more" coarse-grained models in the long pathway connecting SAP sequences and hydrogel mechanical properties.