Red-to-near-infrared self-reporting photosensitizers with high photostability for photodynamic therapy

Abstract

Photodynamic therapy (PDT) is a promising tumor treatment method, in which the design of photosensitizers is particularly critical. Red-to-near-infrared (NIR) photosensitizers are beneficial to the implementation of the PDT process. However, the visualizable self-reporting PDT process cannot be fulfilled because most red-to-NIR photosensitizers have poor photostability. Here, we report a photostable red-to-NIR D-A-D photosensitizer (TPA-BPY) using BOPHY as the acceptor and triphenylamine as the donor. As far as we know, TPA-BPY is the first red-to-NIR BOPHY photosensitizer with advantages such as large molar extinction coefficient and high photostability. TPA-BPY can induce the production of singlet oxygen (1O2) under light, successfully achieving photodynamic therapy for MCF-7 cells. More importantly, TPA-BPY achieved self-reporting of the PDT-induced apoptosis process. TPA-BPY was localized in lysosomes and monitored for increased polarity during lysosomal storage and decreased polarity of apoptotic cells. This work provides an effective strategy for constructing polar sensitive near infrared self-reporting photosensitizers for PDT and its process monitoring.