Red haloBODIPYs as theragnostic agents: The role of the substitution at meso position.

Three different molecular designs based on BODIPY dye have been proposed as photosensitizers (PSs) for photodynamic therapy (PDT) by the inclusion of halogen atoms (Iodine) at 2,6-positions and with extended conjugation at 3, 5-positions and varying the substitution at meso position. The synthesis is described and their main photophysical features including singlet oxygen production and triplet states were characterized by absorption and fluorescence spectroscopy (steady-state and time-correlated) and nanosecond transient absorption spectroscopy. The results were compared with the commercial Chlorin e6. The three new red-halogen-BODIPYs showed a great balance between singlet oxygen generation (Φ Δ ≥0.40) and fluorescence (Φ fl ≥0.22) for potential application on PDT, and particularly in theragnosis. In vitro experiments in HeLa cells were done to study their performance and to elucidate the best potential candidate for PDT. [Display omitted] • Design and characterization of new red-haloBODIPYs as theragnostic agents in PDT. • Substitution pattern at meso position controls the cellular uptake of PS. • High phototoxic action against HeLa cells has been reached (EC 50 = 10 nM). • Better performance under light irradiation than the commercial Chlorine e6 without any cytotoxicity in dark conditions. [ABSTRACT FROM AUTHOR]