An injectable supramolecular hydrogel hybridized with silver nanoparticles for antibacterial application

Silver nanoparticles (AgNPs) show long-lasting and broad-spectrum antibacterial activity. Herein, PEGylated AgNPs were prepared in situ by complexing AgNO3 with the random copolymer of poly(ethylene glycol) methyl ether methacrylate (PEGMA) and polyacrylic acid via electrostatic interaction followed by in situ reduction. AgNP hybrid supramolecular hydrogels were thus prepared through host-guest inclusion between PEGMA side chains and alpha-cyclodextrins in aqueous solution. The hydrogels were physically cross-linked by both pseudopolyrotaxane crystallization and AgNPs, which showed temperature responsiveness and self-healing properties. By hybridizing AgNPs, the hydrogels showed excellent antibacterial properties against S. aureus and E. coli bacteria as well as low cytotoxicity and have potential applications as injectable antibacterial materials.