Copper-incorporated hydrogels loaded with curcumin microspheres for the repair of bone defects

Addressing bone defects continues to be an exceedingly difficult challenge owing to local immune dysregulation, vascular injury, and disorders of osteogenesis. No entirely satisfactory resolution has been achieved. In this work, through loading curcumin/poly (lactic-co-glycolic acid) microspheres constructed via a double emulsion technique, a copper-incorporated carboxymethyl chitosan/sodium alginate hydrogel (CA-Cur@Cu hydrogel) was developed. The CA-Cur@Cu hydrogels can sustain the release of curcumin for a long time. This sustained release demonstrates effective antioxidant and anti-inflammatory properties, inducing M2 polarization of macrophages and enhancing the bone immune microenvironment. Furthermore, Cu²⁺ released from the CA-Cur@Cu hydrogels induces angiogenesis and osteogenesis, which synergize with anti-inflammatory properties of curcumin to accelerate the repair of bone defects. Additionally, the CA-Cur@Cu hydrogels exhibit remarkable antibacterial activity, effectively inhibiting clinical bacterial infections. Overall, this study successfully constructed a multifunctional hydrogel integrating antioxidant, anti-inflammatory, pro-angiogenic, and osteogenic properties, providing a new perspective and potential solution for the treatment of bone defects.