Polylactic acid-Ag@Sr composite membranes with balanced osteogenic and antibacterial properties for guided bone regeneration.

Repairing large craniofacial bone defects presents a significant clinical challenge, primarily due to the elevated risk of bacterial infection and impaired osteogenic activity at the defect site. Herein, PLA-Ag@Sr composite nanofiber membranes with dual osteogenic and antibacterial properties for treating infected skull defects are reported, achieved by integrating dual-function core-shell Ag@Sr mesoporous silica nanoparticles (Ag@MSN@Sr) into PLA nanofibers via one-pot electrospinning method, effectively addressing the limitations of single functionality, structural complexity, and poor stability inherent in conventional multi-component GBR membranes. PLA-Ag@Sr exhibits favorable mechanical properties, moderate hydrophilicity, and sustained release of Ag and Sr ions. In vitro cellular assays indicated that the PLA-Ag@Sr possesses excellent biocompatibility and enhances osteogenic differentiation. Antibacterial assessments further confirmed the effective antibacterial activity of PLA-Ag@Sr in both in vitro and in vivo. Moreover, evaluations on calvarial defect rat model demonstrated the outstanding biocompatibility and significant osteogenesis potential of PLA-Ag@Sr. The synergistic combination of Sr (for osteogenic stimulation) and Ag (for broad-spectrum antibacterial action) in our core-shell system provides a new "kill two birds with one stone" idea with balanced osteogenesis and antibacterial properties for treating infected bone defects.