Biomimetic injectable methacrylated chondroitin sulfate–collagen hydrogels enhance chondrocyte function and promote osteochondral regeneration

implantation in a rat full-thickness cartilage defect model demonstrated that CSMA-based composite hydrogels facilitated seamless defect filling, enhanced proteoglycan and glycosaminoglycan deposition, and promoted subchondral bone remodeling. Among all formulations, CS5M1 achieved the most complete repair, regenerating hyaline-like cartilage integrated with surrounding tissue after 12 weeks. Collectively, these results demonstrate that the composite hydrogels provide a biomimetic, injectable, and photo-curable platform with excellent osteochondral regenerative potential.