A hydrogel derived from skin secretion of Andrias davidianus to facilitate bone regeneration

Bone regeneration relies heavily on balancing osteogenesis and osteoclastogenesis. Meeting the challenge of creating bone repair scaffolds with dual functionalities has long been elusive in bone tissue engineering. This study addresses these challenges through the utilization of a unique hydrogel that capitalizes on the dynamics of disulfide bonding to convert the skin secretion of Andrias davidianus (SSAD) into hydrolysate. This hydrolysate serves as the foundation for the construction of a novel SSAD protein hydrogel for bone regeneration, achieved through a photo-redox reaction under visible light crosslinking. The innovative SSAD protein hydrogel not only exhibits exceptional biocompatibility but also significantly enhances bone mineralization and angiogenesis in vitro. RNA sequencing delves into the underlying mechanisms governing the regulation of osteogenesis and osteoclastogenesis by the hydrogel. In vivo experiments conclusively demonstrate the potential of the SSAD protein hydrogel. It expedites vascularization within the defect area and synergistically facilitates the repair of bone defects. Furthermore, the SSAD hydrogel exhibits notable antimicrobial properties, effectively reducing the risk of implant-related infections in vivo. In summary, this research introduces a valuable and promising method for fabricating protein biomaterials that contribute to bone repair by promoting both bone and blood vessel growth while simultaneously inhibiting osteoclast formation.