Heavy atom substituted near-infrared BODIPY nanoparticles for photodynamic therapy

Abstract

Photodynamic therapy (PDT) is a promising alternative to cancer therapy for its non-invasive advantage. The rational design of ideal photosensitizers (PSs) is especially significant in PDT. Herein, we synthesized a diiodo-substituted BODIPY (SNBDP) with near-infrared (NIR) region absorption and fluorescence emission by Knoevenagel condensation reaction. The SNBDP nanoparticles (NPs) were prepared by the nanoprecipitation method wrapped by poloxamer. As-prepared SNBDP NPs exhibited robust water stability and notable photostability. After cellular endocytosis, the NPs could elicit excellent cancer-killing effects with a low half maximal inhibitory concentration (10.55 μM for HeLa and 13.46 μM for A549 cells) due to good singlet oxygen quantum yield (ΦΔ = 40%) of PS derived from the heavy atom effect. Moreover, the favorable cancer cell inhibition efficacy could efficiently reduce the dark toxicity of drug. We believe this ingenious design could provide a reference value for the exploration of optimal PS for PDT.