Self-Repairing Filamentous Actin Hydrogel with Hierarchical Structure

A chemically cross-linked filamentous actin (F-actin) gel consisting of globular actin (G-actin) as repeating units was prepared. The F-actin gel was cross-linked by covalent bonds, and the main chain is represented by the self-assembly of G-actin with a high-ordered hierarchical structure. The gel exhibited good mechanical performance with a storage modulus >1 kPa and undergoes reversible sol-gel transitions in response to changes in the salt concentration (chemical-induced sol-gel transition) as well as to shear strain (mechanical-induced sol-gel transition). Therefore, the gel exhibits self-repairing ability through dynamic polymerization and depolymerization across the structure hierarchies under repeated shear stress.