Improved Stability and Photodynamic Activity of Water‐Soluble 5,15‐Diazaporphyrins Incorporated in β‐(1,3‐1,6)‐d‐Glucan with On‐Off Switch

• Published in: Chemistry, an Asian journal an Asian journal, 2020-02, Vol.15 (3), p.365-370
• Main Authors: Hino, Shodai, Satake, Shuhei, Shinmori, Hideyuki, Kawabata, Shigeki, Koumoto, Kazuya, Suzuki, Toshio, Nagasaki, Takeshi, Sugikawa, Kouta, Kawasaki, Riku, Ikeda, Atsushi
• Format: Article
• Language: English
• Subjects: aggregation; Aqueous solutions; Chemistry; Complex formation; Cyclodextrins; Fluorescence; fluorescent probes; Glucan; host-guest systems; Liposomes; polysaccharide; porphyrinoids
• ISSN: 1861-4728; 1861-471X
• DOI: 10.1002/asia.201901582

5,15‐Diazaporphyrins, which have a large absorption at wavelengths over 600 nm, were dissolved in water by complex formation with β‐(1,3‐1,6)‐d‐glucans. Aqueous solutions of these complexes were relatively stable compared with their trimethyl‐β‐cyclodextrin‐complexed analogues. β‐Glucan‐complexed diazaporphyrins showed quenched fluorescence and had low singlet‐oxygen‐generation abilities owing to random self‐aggregation. However, external stimuli, such as the presence of liposomes or intracellular uptake, restored the fluorescence and singlet‐oxygen‐generation abilities of β‐glucan‐complexed diazaporphyrins. Consequently, β‐glucan‐complexed diazaporphyrins showed very high photodynamic activities toward HeLa cells. β‐1,3‐Glucan‐complexed 5,15‐diazaporphyrins changed from “off‐state” to “on‐state” toward fluorescence and photodynamic activity upon intracellular uptake.