AIE-driven photothermal nanotrigger-activated multifunctional injectable hydrogel for maxillofacial infection control

The treatment of maxillofacial infections and wounds remains highly challenging due to the risk of facial deformities and the resulting psychological trauma. Furthermore, the irregular geometry and complex anatomical structures of maxillofacial wounds hinder effective clinical intervention. Therefore, the development of controllable and multifunctional composite hydrogels is highly desirable for promoting tissue regeneration, particularly in cases involving irregularly shaped tissue defects. In this study, we developed AIE-induced photothermal nanotrigger strategy for fabricating injectable multifunctional hydrogel zwitterionic wound dressing. This antibacterial composite zwitterionic hydrogel (TSD NPs@Gel) was synthesized using sulfobetaine methacrylate (SBMA) as the monomer, N,N'-methylenebisacrylamide (MBAA) as the crosslinker, and ammonium persulfate (APS) as the initiator. By incorporating aggregation-induced emission (AIE) nanoparticles (TSD NPs), we leveraged their excellent photothermal properties to achieve a "photothermal self-catalysis (PSC)" effect. Under light irradiation, TSD NPs generated heat, which accelerated the decomposition of APS into free radicals, thereby promoting the polymerization between the monomer and crosslinker. This innovative approach eliminated the need for traditional chemical catalysts and enabled the efficient preparation of the hydrogel. This hydrogel exhibits synergistic antibacterial effects through photothermal (PTT) and photodynamic (PDT) therapies. Under 660 nm laser irradiation, TSD NPs@Gel efficiently generates PTT and PDT effects, demonstrating significant bactericidal efficacy against both Gram-positive bacteria (<i>Staphylococcus aureus</i>) and Gram-negative bacteria (<i>Escherichia coli</i>). Additionally, mouse wound experiments show that the TSD nanoparticle-loaded hydrogel can effectively adhere to the facial skin of mice. The zwitterionic properties of the hydrogel provide excellent moisturizing and immunomodulatory effects, promoting blood vessel regeneration and new tissue growth, thereby demonstrating superior healing capabilities in mouse models of maxillofacial infections and traumas.