Plasmon-enhanced schottky nanoscaffolds for phototherapy and catalytic treatment of multidrug-resistant bacterial infections

Chronic wounds caused by multidrug-resistant (MDR) bacterial infections pose a significant challenge to healthcare systems. Nanofiber scaffolds that mimic the extracellular matrix (ECM) offer potential in wound healing due to their porous structure and large surface area. In this study, a bionic nanofiber scaffold, single-layer titanium carbide (Ti₃C₂T_x)/oxygen deficient molybdenum oxide (MoO_3-x)@PLA/PANI (T/M@PLA/PANI), is developed through a solution blow spinning process, where Ti₃C₂T_x/MoO_3-x (T/M) nanoparticles are embedded in a poly(lactic acid) (PLA) matrix, followed by in situ polymerization of polyaniline (PANI) on the surface. Under 808 nm laser irradiation, the T/M Schottky heterojunction within the composite scaffold exhibits superior photothermal conversion performance due to the enhanced localized surface plasmon resonance (LSPR) effect, outperforming the individual components. Furthermore, MoO_3-x is found to exhibit type-I photodynamic therapy (PDT) activity, and the formation of the T/M heterojunction in the T/M@PLA/PANI scaffold enhances type-I PDT while maintaining the type-II PDT activity of Ti₃C₂T_x. The scaffold also retains the peroxidase (POD)- and glutathione oxidase (GSHOx)-mimicking activities of MoO_3-x, further boosting antibacterial efficacy. Additionally, the introduction of PANI significantly improves the scaffold’s conductivity, promoting cell proliferation, migration, angiogenesis, wound healing, and inflammation reduction while further enhancing the photothermal conversion performance of T/M@PLA. In vivo studies confirm that the T/M@PLA/PANI scaffold effectively eliminates MDR bacterial infections and promotes wound healing through the combined effects of photothermal therapy (PTT), type I/II PDT, and catalytic antimicrobial activities, as well as electrical stimulation, offering a promising strategy for addressing infection in chronic wounds.