A near-infrared and lysosome-targeted coumarin-BODIPY photosensitizer for photodynamic therapy against HepG2 cells

Abstract

Photodynamic therapy (PDT) is a promising modality to treat cancer therapy for its non-invasive advantage and good selectivity. Herein, an iodinated and coumarin fused BODIPY photosensitizer named as BDP-C with near-infrared (NIR) region absorption was designed and synthesized for PDT against cancer cells. The absorption and emission wavelength of BDP-C appears at 732 nm and 808 nm, respectively. Its molar absorption coefficient is up to 2.13 × 105 cm−1M−1. The photosensitizer BDP-C shows good ability to yield singlet oxygen (1O2) and its 1O2 yield was calculated to be 17% using methylene blue (MB) as the reference, and then the photodynamic properties of BDP-C were investigated through MTT assays and confocal fluorescence imaging. The results show that the photosensitizer BDP-C has good biocompatibility and photostability, good long-term cell imaging ability, and moderate 1O2 generation efficiency. In addition, BDP-C can also specifically target lysosomes and kill HepG2 cells through apoptosis pathway upon laser irradiation. It will be a promising candidate drug in the field of biologic imaging and PDT.