Enhanced repair of osteoporotic bone defects through gelatin methylacryloyl loaded with exosomes

Treating bone defects presents a formidable clinical challenge. The sustained release of exosomes (Exos) by hydrogel-based materials can contribute substantially to bone formation through bioactive paracrine secretion of bone marrow mesenchymal stem cells (BMSCs). Our study proposed a method to use an extracellular matrix-simulated gelatin methylacryloyl (GM) hydrogel loaded with BMSC-derived Exos for repairing bone defects. Using BMSCs, we isolated Exos and characterized them. These Exos were then loaded into GM hydrogel and studied for their osteogenic effects in vitro and in vivo. The results showed that GM hydrogel had good biocompatibility and showed good Exo carrier characteristics. In addition, Exos derived from BMSCs played a significant role in promoting the proliferation of BMSCs, and GM hydrogel could enhance this effect through slow release. Similarly, in vivo experiments have shown that GM-Exos promoted bone regeneration and related osteoblast protein synthesis in cranial defects in rats.