[P006] Poster

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

[P03-342] Meso-Phenyl Substituent Effects on Photophysical and Photodynamic Activity in Cationic BODIPY Photosensitizers

○Arrhon Mae Bongo¹, Ho-Joong Kim¹ (1. Chosun University (Korea))

Keywords:

BODIPY photosensitizers,Photodynamic therapy (PDT),Mitochondrial targeting,Fluorescence imaging

Quaternary ammonium-functionalized water-soluble BODIPY photosensitizers were synthesized to investigate the influence of meso-phenyl electronic substitution on photophysical properties and photodynamic therapy (PDT) performance. A series of cationic BODIPY derivatives bearing para-substituents (–H, –OMe, –NO₂, and –I) were prepared via azide–alkyne click chemistry using a fixed mitochondrial-targeting scaffold. Photophysical properties, singlet oxygen generation, cellular phototoxicity, and subcellular localization were evaluated through spectroscopic analysis, photodynamic assays in MCF-7 cancer cells, and confocal fluorescence imaging. All compounds exhibited characteristic BODIPY absorption and fluorescence profiles. The iodine-substituted derivative showed enhanced singlet oxygen generation due to the heavy-atom effect, while the methoxy-substituted derivative demonstrated efficient photodynamic activity despite lacking halogens. In contrast, the nitro-substituted compound exhibited fluorescence quenching and minimal PDT efficiency. Cellular studies revealed negligible dark cytotoxicity but significant light-induced phototoxicity for the iodine- and methoxy-substituted derivatives. Confocal fluorescence imaging confirmed preferential mitochondrial localization. These results demonstrate that meso-phenyl electronic tuning is an effective strategy for balancing fluorescence imaging capability and photodynamic activity in mitochondria-targeted BODIPY photosensitizers.