posted on 2023-05-19, 13:35authored byJian Zhao, Rong Huang, Ya Gao, Jiadong Xu, Yanyan Sun, Jiayuan Bao, Lei Fang, Shaohua Gou
Development of near-infrared (NIR) Type-I photosensitizers
is attracting
tremendous attention to overcome the limitation of traditional O2-dependent Type-II photosensitizers, but huge challenges remain.
Herein, a promising concept was put forward by lowering the energy
of the lowest triplet excited state (T1) of the photosensitizer
below the threshold for oxygen sensitization via maximizing the electronic
exchange energy. By taking advantage of the low energy intramolecular
charge transfer (ICT) state, pyrrolidine as an electron donor is conjugated
at the bay position of perylenediimide (PDI) to produce PDIPy that
acts as a novel photosensitizer with NIR absorbance and low T1 energy level. With the application of PDIPy, Type-I PDT is
realized via effective generation of O2• –. Supramolecular nanoparticles (NanoPDIPy) assembling from PDIPy
showed excellent in vitro and in vivo phototherapeutic efficacy against
cancer in either normoxia or hypoxia upon 730 nm laser irradiation.