Self-healing biopolymers

Protein metal complexes as reversible sacrificial bonds in self-healing biopolymers

MPI Golm

Byssal threads are biopolymeric fibers secreted by marine mussels that exhibit autonomic and intrinsic self-healing behavior . Because threads are protein-based and acellular, they present an appealing biomimetic model system for inspiring the development of self-healing polymers. Previous studies indicate that healing behavior results from reversible protein-metal cross-links; however, it is still unclear how factors such as cross-link density and distribution, choice of ligand-metal combination, or the hierarchical organization of the protein subunits influence the self-healing behavior. We propose a cross-disciplinary research project directed at better understanding the role metal-protein complexes play as reversible cross-links in the selfhealing behavior of the fibrous core and protective cuticle of byssal threads. Furthermore, we aim to elucidate how self-healing behavior is modified and enhanced through higher order organization of such cross-links. Accordingly, a comparative biological approach using threads from several related species will be undertaken in parallel to examine how healing behavior has been adapted and optimized to different physical conditions by evolution. By investigating the healing behavior of byssal threads at the molecular level up through higher levels of hierarchy, we expect to extract material-independent structural and chemical design principles to inspire the production of autonomic and intrinsic self-healing polymers.