All-in-one phototheranostics based on BTP-4F-DMO nanoparticles for NIR-II fluorescence/photoacoustic dual-mode imaging and combinational therapy

Various phototheranostics have recently been developed for phototherapy. Through proper molecular design, the photochemical and photophysical properties of these phototheranostics can be promoted. Herein, an acceptor-donor-acceptor (A-D-A)-structured dye, BTP-4F-DMO, was synthesized and prepared into water-soluble nanoparticles (NPs). The obtained BTP-4F-DMO NPs had strong absorption from 650 nm to 850 nm and a fluorescence emission peak at similar to 900 nm that tailed to similar to 1100 nm. The NPs showed a superhigh photothermal conversion efficiency of 90.5% +/- 5% and could simultaneously generate center dot OH and 1 O 2 with a 1 O 2 generation quantum yield of 4.6% under 808 nm laser irradiation. Due to these advanced properties, BTP-4F-DMO NPs can switch the role of autophagy from pro-survival to prodeath, thereby further promoting cancer cell death. These features make BTP-4F-DMO NPs a promising multifunctional phototheranostic agent for NIR-II fluorescence/photoacoustic dual-mode imaging-guided synergetic photodynamic/photothermal therapy. In general, this work provides a strategy for expanding the biomedical applications of organic A-D-A-structured phototheranostics. (c) 2023 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.