• The quercetin-loaded polyethyleneimine/oxidized dextran hydrogel exhibited sustained drug release for up to 42 days, with an initial burst release within 3 days.
• In vitro, the hydrogel demonstrated significant antibacterial activity against Staphylococcus aureus, Escherichia coli, and methicillin-resistant Staphylococcus aureus, and promoted osteogenic differentiation of rabbit bone marrow mesenchymal stem cells.
• In a rat model of infected femoral defects, the hydrogel significantly enhanced new bone formation and reduced bacterial presence compared to controls.
• The composite hydrogel offers a promising strategy for treating infected bone defects by combining antibacterial and osteogenic functions in a single delivery system.