Antibiotic and growth factor-loaded hydrogels for infected bone defect repair: mechanisms of spatiotemporal delivery and cellular microenvironment regulation

The treatment of infected bone defects (IBDs) requires simultaneous infection control and bone regeneration. However, traditional staged treatment protocols have several limitations. These include extended treatment durations, multiple surgical procedures, and low repair efficiency. Bifunctional hydrogels loaded with antibiotics and growth factors (GFs) offer a crucial material platform for integrated treatment strategies. These hydrogels possess excellent biocompatibility, malleability, and the capacity for spatiotemporal drug delivery. This review summarizes the design principles of antibiotic- and GF-loaded hydrogels, with particular attention to sequential and synergistic release strategies and their roles in infection control, immune regulation, vascularization, and osteogenesis. Current in vitro and in vivo evaluation approaches are also discussed, together with remaining challenges in drug stability, release precision, long-term biosafety, and clinical translation. This review may provide a basis for the rational design of multifunctional hydrogel systems and their further development for infected bone defect repair.