BODIPY-Based Fluorescent Surfactant for Cell Membrane Imaging and Photodynamic Therapy

Fluorescent dyes are widely used in chemical, biological, and environmental science. However, the π-π stacking among the large π-conjugated groups of the dye molecules normally leads to the hydrophobicity and aggregation, resulting in quenching the fluorescence intensity. In the present work, a kind of BODIPY-based fluorescent surfactant C8BCOONa has been synthesized, and its self-assembly and performances in cell membrane imaging and photodynamic therapy have been studied. This fluorescent surfactant exhibits low critical micellar concentration (CMC) in aqueous solution and forms vesicles above the CMC. The fluorescence intensity of C8BCOONa significantly increases with aggregating into the DOPC vesicles, in which C8BCOONa inserts into the bilayer of DOPC vesicles through hydrophobic interaction and the intramolecular rotation of C8BCOONa is restrained in the aggregates. The fluorescent surfactant of low concentration displays negligible dark- and photocytotoxicity to MCF-7 cells and HeLa cells and can effectively stain the living cell membrane with a long retention time. Meanwhile, a large amount of reactive oxygen species is generated by higher concentration C8BCOONa under white light and brings obvious photocytotoxicity to the two types of cancer cells. Therefore, this kind of fluorescent surfactant shows a great potential in targeted bioimaging and efficient photodynamic therapy.