Synthesis and photodynamic activity of novel thieno[3,2–b]thiophene fused BODIPYs with good bio-solubility and anti-aggregation effect

Abstract

To discover new photosensitizers with long wavelength UV–visible absorption, high efficiency, and low side effects for photodynamic therapy, here, a series of novel thieno[3,2–b]thiophene-fused BODIPY derivatives were designed, synthesized and characterized. These compounds had a distinct absorption band at 640–680 nm, fluorescence emission at 650–760 nm, and good solubility with anti-aggregation effects. These new compounds possessed obvious singlet oxygen generation ability and photodynamic anti-Eca-109 cancer cells activities in vitro. Among them, compound II4 could be well uptaked by Eca-109 cells, and result in the apoptosis after laser irradiation, and have outstanding photodynamic efficiency both in vitro and in vivo. Therefore, II4 could be considered as a potential photosensitizer drug candidate for PDT and photo-imaging.