An ultra-stable bio-inspired bacteriochlorin analogue for hypoxia-tolerant photodynamic therapy. Issue 4 (14th December 2020) - Wu, Mengsi
Abstract : A hypoxia-tolerant photosensitizer FBC -based nanoplatform with strong NIR absorbance and ultra-high stability was facilely prepared for PDT of deep tumors. Abstract : Photodynamic therapy (PDT) greatly suffers from the weak NIR-absorption, oxygen dependence and poor stability of photosensitizers (PSs). Herein, inspired by natural bacteriochlorin, we develop a bacteriochlorin analogue, tetrafluorophenyl bacteriochlorin (FBC ), by one-step reduction of tetrafluorophenyl porphyrin (TFPP ). FBC can realize deep tissue penetration, benefitting from the strong NIR absorption. The reactive oxygen species (ROS) generation capacity of FBC can retain around 60% with a 1.0 cm-thick pork skin as the barrier. Besides, FBC could not only produce oxygen-dependent 1 O2, but also generate less oxygen-dependent O2 − ˙ and ˙OH to achieve excellent PDT even in hypoxic tumors. Moreover, FBC exhibits an ultra-high stability and it is almost unchanged even under visible light at room temperature for 15 months. Interestingly, the high reactivity of the fluorophenyl group makes it easy for FBC to produce FBC derivatives. A biocompatible FBC nanogel could be directly formed by blending FBC with SH–PEG–SH. The FBC nanogel displays excellent photodynamic efficacy in vitro and in vivo . Thus, FBC would be a promising PS for the clinical PDT of deep tumors.