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@MnO₂-gel) was developed for the treatment of bacteria-infected wounds. The norfloxacin (NOR)-loaded manganese dioxide-modified mesoporous silica (NOR-MSN@MnO₂) nanoparticles were selected as a photothermal material and encapsulated in the furfuryl amine-modified hyaluronic acid hydrogel (HA-FA^gel). Studies found that MSN@MnO₂-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@MnO₂-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@MnO₂-gel combined with NIR irradiation (NOR-MSN@MnO₂-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@MnO₂-gel + NIR regimen provides a promising strategy for clinical treatment of bacterial infected wounds.