Promoted intramolecular photoinduced‐electron transfer for multi‐mode imaging‐guided cancer photothermal therapy
Xinyu Qu, Ying Hong, Han Cai, Xu Sun, Qing Shen, Dongliang Yang, Xiaochen Dong, Aihong Jiao, Peng Chen, Jinjun Shao
Abstract
Abstract To develop smart and efficient near‐infrared (NIR) organic dyes for photothermal cancer therapy is of great challenge. Herein, a pH‐sensitive NIR dye BTN with donor–acceptor–donor scaffold has been synthesized. Two periphery electron‐donating dimethylamine groups in BTN can not only promote the intramolecular photoinduced electron transfer (PET), but also bind protons to transform into electron‐deficient ammonium cation for enhanced intramolecular charge transfer (ICT) under acidic circumstance. Through enveloping with amphiphilic polymeric 1,2‐distearoyl‐ ras ‐glycerol‐3‐phosphatidyl ethanolamine‐N‐polyethyleneglycol‐2000 (DSPE‐ m PEG 2000 ), BTN nanoparticles (NPs) were fabricated with robust NIR absorption covering 600–900 nm, excellent photothermal conversion efficiency (43.2%), and good photostability. Additionally, BTN NPs can selectively target lysosomes. Through tailing intravenous injection into tumor‐bearing nude mice, BTN NPs demonstrate outstanding photoacoustic/photothermal/fluorescence imaging‐guided photothermal therapy for tumor ablation.