Abstract
Bacterial infections and subsequent inflammation are major obstacles to efficient wound healing and present an increasing clinical challenge due to rising antimicrobial resistance. Photothermal therapy (PTT) offers a non-antibiotic, spatiotemporally controllable strategy to eradicate pathogens. However, the development of promising photothermal agents with high NIR response, biocompatibility and facile preparation is still challenging. Here we report supramolecular assembled donor-acceptor charge-transfer complex (CTC) nanoparticles TPD-TCB (TT NPs) achieved by precise modulation of energy-level engineering between commercially available donor and acceptor molecules. CTC formation yields a narrowed effective HOMO-LUMO gap, which enables TT NPs to exhibit broad NIR absorption extending toward ∼1200 nm and a photothermal conversion efficiency of 38 %. Notably, under 808 nm irradiation TT NPs achieve potent photothermal killing of Gram-positive (90.7 %) and Gram-negative (94.9 %) bacteria in vitro and effectively suppress infection in an in vivo wound model. Additionally, TT NPs + NIR accelerate wound closure by clearing pathogens, resolving inflammation and promoting epidermal differentiation and regeneration. This work establishes a practical and generalizable CTC-based bandgap engineering strategy for creating high-performance organic photothermal agents suitable for antibacterial therapy and wound repair.