A composite hydrogel functionalized by hydroxyapatite and ceria quantum dots for regeneration of critical-sized...

Critical-sized bone defects represent a prevalent and intractable challenge in orthopedic due to poor self-healing ability and prolonged treatment cycles. Biomaterials are recognized as promising strategies for effective bone defect repair, for the capability of regulating microenvironment and facilitating osteogenic differentiation. Herein, an inorganic-organic multifunctional composite hydrogel was developed with methacrylated gelatin (GelMA) as the matrix, functionalized with alendronate modified ceria quantum dots (AHA@CQDs) and nano-hydroxyapatite (nHAP). AHA@CQDs regulated local oxidative stress to promote cell proliferation and differentiation, while nHAP enhanced osteogenic differentiation and mechanical stability of the hydrogel. In vitro experiments confirmed that the composite hydrogel exhibited excellent biocompatibility, antioxidant property and cell migration ability, while also exhibiting remarkable potential in promoting the proliferation and osteogenic differentiation of rat bone marrow mesenchymal stem cells (BMSCs). Furthermore, after being implanted into a rat cranial defect model, the composite hydrogel significantly promoted new bone formation and upregulated the expression of osteogenic related biomarkers. Collectively, this multifunctional composite hydrogel provides an effective approach for repairing critical-sized bone defects.