Dark and photoinduced cytotoxicity of solubilized hydrophobic octa-and hexadecachloro-substituted lutetium(III) phthalocyanines

Chloro-substituted lutetium(III) phthalocyanines were obtained using fast and effective (yields 75–78%) template synthesis under microwave irradiation. Target compounds possess intense (logε ∼ 5) absorption in the range 680–700 nm, which overlaps with the “therapeutic window” range for photosensitizers in photodynamic therapy. Chloro-substituted complexes demonstrate moderate quantum yields (up to 54% for perchlorinated complex) of singlet oxygen generation. Moreover, chloro-substituted lutetium(III) phthalocyanines showed the ability to generate the superoxide anion radical (O2–•) with higher efficiency compared to unsubstituted analog. Stable colloid suspensions of the water-soluble nanoparticles were obtained by incorporation of the chlorinated lutetium(III) phthalocyanines into mixed polylactide micelles. The dark and photoinduced cytotoxic activity of the obtained nanoparticles was tested using the HeLa cell line. Demonstrated results showed a promising potential of the chlorinated lutetium(III) phthalocyanines as photosensitizers for medical applications.