[P006] Poster

1:00 PM - 1:50 PM JST(4:00 AM - 4:50 AM UTC)

[P03-344] Heavy-Atom-Enhanced Singlet Oxygen Generation in Cationic 2,6-Halogenated BODIPY Photosensitizers

○yeonghyeon Son¹, Ho-Joong Kim¹ (1. Chosun university (Korea))

Keywords:

BODIPY Photosensitizers,Photodynamic Therapy (PDT),Fluorescence Imaging,Singlet Oxygen Quantum Yield

Water-soluble BODIPY photosensitizers are promising candidates for fluorescence imaging–guided photodynamic therapy (PDT), although conventional BODIPY dyes often suffer from poor aqueous compatibility and low singlet oxygen generation. In this study, three cationic water-soluble BODIPY derivatives (BHTM, BBrTM, and BITM) were synthesized via CuAAC click functionalization to introduce a quaternary ammonium group, while 2,6-halogenation with bromine or iodine was employed to enhance intersystem crossing through the heavy-atom effect. Compared with the non-halogenated analogue BHTM, the brominated and iodinated derivatives exhibited significantly higher singlet oxygen quantum yields (ΦΔ = 0.59 for BBrTM and 0.91 for BITM vs 0.11 for BHTM). In vitro studies using MCF-7 and HeLa cancer cells showed negligible dark cytotoxicity (>95% viability at 400 nM) but pronounced photocytotoxicity under 530 nm irradiation, consistent with efficient reactive oxygen species generation. Confocal laser scanning microscopy further confirmed strong cellular uptake with bright fluorescence signals and predominant cytoplasmic localization. These results demonstrate that combining cationic hydrophilization with 2,6-halogenation effectively converts BODIPY fluorophores into dual-function, water-compatible photosensitizers for fluorescence imaging–guided photodynamic therapy.