Multiple rotors-based photothermal agents for NIR-I/NIR-II fluorescence imaging-guided tumor phototherapy

Abstract

Photothermal therapy (PTT) emerges as a promising alternative therapy for tumor ablation through spatiotemporally controlled hyperthermia. However, designing near-infrared photothermal agents with a high photothermal conversion efficiency (PCE) and high photostability remains considerably challenging. To address the limitation, we constructed a photothermal agent 3TPA by employing CF3-BODIPY as an electron-withdrawing core and incorporating three electron-donating triphenylamine rotors, which showed an extended absorption wavelength and improved PCE. To optimize therapeutic performance, 3TPA was further encapsulated into DSPE-mPEG5K-based amphiphilic polymer to form 3TPA NPs which exhibited high PCE (η = 57.2%) and remarkable photostability. In vivo studies revealed that 3TPA NPs selectively accumulated in tumor sites under NIR-I/NIR-II fluorescence imaging guidance, simultaneously enabling effective photo-mediated tumor ablation through precision PTT effect. This work not only presents a robust NIR-II therapeutic agent but also opens up more possibilities for its application in photothermal therapy in the field of biomedicine.