NIR-responsive MnO2-functionalized mesoporous silica hydrogel: Fabrication and antibacterial activity evaluation

In this study, an 808 nm near-infrared (NIR)-responsive hydrogel (NOR-MSN@MnO 2 -gel) was developed for the treatment of bacteria-infected wounds. The norfloxacin (NOR)-loaded manganese dioxide-modified mesoporous silica (NOR-MSN@MnO 2 ) nanoparticles were selected as a photothermal material and encapsulated in the furfuryl amine-modified hyaluronic acid hydrogel (HA-FA gel ). Studies found that MSN@MnO 2 -gel exhibited a three-dimensional porous network structure, favorable injectability, excellent water absorption & retention capacity, and desirable photothermal conversion efficiency. Benefiting from pH/NIR dual-responsive characteristics, NOR-MSN@MnO 2 -gel realized controllable NOR release and achieved efficient elimination of Staphylococcus aureus ( S. aureus ) and Escherichia coli ( E. coli ) through synergistic photothermal therapy (PTT) and chemotherapy. In vivo infected wound studies demonstrated that NOR-MSN@MnO 2 -gel combined with NIR irradiation (NOR-MSN@MnO 2 -gel + NIR) could effectively inhibit bacterial growth, alleviate inflammation, accelerate re-epithelialization, and promote collagen deposition & angiogenesis, while maintaining satisfactory biological safety. Collectively, the NOR-MSN@MnO 2 -gel + NIR regimen provides a promising strategy for clinical treatment of bacterial infected wounds.