Photophysics and photobiology of novel liposomal formulations of 2,9(10), 16(17),23(24)-tetrakis[(2-dimethylamino)ethylsulfanyl]phthalocyaninatozinc(II)

Abstract

Six novel liposomal formulations of 2,9(10),16(17),23(24)-tetrakis[(2-dimethylamino)ethylsulfanyl]phthalocyaninatozinc(II) (Pc9) were investigated to establish how the environments affect their photophysical and photobiological properties. The incorporation efficiency and solubility during a time period were evaluated. All Pc9-liposomal formulations were efficient singlet oxygen quantum yield generators. The photobiological potentials were evaluated on human nasopharynx KB carcinoma cells. None of the formulations studied showed cytotoxic effects in the absence of light, whereas all of them showed good performance after irradiation. The 50% inhibition of cell proliferation (IC50) was in the range of 0.21–0.47 μM for Pc9-loaded liposome formulations. A lysosomal localization was found for S-PEG as well as for S.