Design and Development of ZnO/BMP-2 Sustained-Release Hydrogel for Enhanced Bone Tissue Repair

Bone infections caused by microbial invasion often lead to tissue damage and functional impairment. Although bone implants are a primary clinical approach to reduce recurrence and promote healing, the growing challenge of antimicrobial resistance necessitates innovative postoperative therapies to improve patient outcomes. In this study, a CG@ZnO/BMP-2 hydrogel with rapid antibacterial and bone regeneration capabilities was developed via a self-assembly technique. This approach leverages the chelation interaction between CG and ZnO, as well as the strong hydrogen bonding between CG and BMP-2. The resulting CG@ZnO/BMP-2 hydrogel exhibited a honeycomb-like structure with excellent swelling, water retention, and biodegradability. Antibacterial assays revealed that, under UV irradiation, the hydrogel achieved antibacterial rates of 85.4% against <i>Escherichia coli</i> and 87.3% against <i>Staphylococcus aureus</i>. The incorporation of ZnO conferred sustained antibacterial activity to the hydrogel. In <i>vitro</i> osteogenesis studies demonstrated that BMSCs gradually differentiated into osteoblasts over time, indicating robust osteogenic potential. Collectively, the CG@ZnO/BMP-2 hydrogel demonstrated a combination of effective antibacterial performance and accelerated bone-inducing functionality. This composite hydrogel holds significant promise for applications in bone infection treatment and bone tissue repair, especially for enhancing bone healing and minimizing postoperative infection recurrence.