Magnesium membranes with enhanced antibacterial activity and intercellular communication for stage-adaptive bone defect repair

Biodegradable magnesium membranes hold great promise for guided bone regeneration (GBR), yet their clinical translation is limited by rapid corrosion, insufficient antibacterial activity and poor regulation of osteoimmune microenvironment. Herein, we report an A–B–A sandwich-structured magnesium composite membrane with a gallium- and quercetin-functionalized hydroxyapatite coating, enabling sequential regulation of bone repair. The coating preserves early integrity and depletes bacterial ATP via Ga- and quercetin-mediated antibacterial actions, suppressing biofilms and excessive inflammation. The coating achieved antibacterial rates of 99.9% in vitro and in vivo . As the coating gradually degrades, the exposed magnesium substrate releases Mg ions that act as endogenous stimuli to promote macrophage polarization toward a reparative M2 phenotype and activate osteogenic–angiogenic cascades. The results of animal experiments showed that the coating markedly promoted angiogenesis and bone regeneration, effectively controlling inflammation in the surrounding tissues. This system establishes a stage-adaptive therapeutic platform from biofilm clearance to immune modulation and tissue regeneration, offering a promising strategy for guided bone regeneration in dental fields.