Tough Hydrogels for Remodeling Ruptured Tendons

Abstract Hydrogels have shown broad application potential due to their high water content and excellent interfacial adaptability, however, conventional biocompatible hydrogels often struggle to simultaneously achieve high strength, high toughness, and favorable biocompatibility, thereby limiting their practical applications. Developing new high-performance hydrogel systems capable of overcoming these mechanical limitations remains an important challenge. In this study, we developed a tough hydrogel that combines outstanding mechanical robustness with excellent biocompatibility. By introducing cyclic salt-solution training, dynamic reconstruction of the polymer network was induced, leading to the formation of a stable anisotropic architecture within the hydrogel. Binding-energy calculations support enhanced intermolecular association as a contributor to salt-assisted mechanical reinforcement. The tough hydrogel was further applied to the suture repair of ruptured rabbit tendons, where it maintained stable interfacial integration under complex dynamic in vivo conditions and promoted ordered collagen remodeling and functional tissue recovery. The tough hydrogel fabrication strategy proposed in this work provides a new approach for the development of high-performance hydrogels for applications in tissue repair, flexible bioelectronics, and advanced soft materials.