The photophysicochemical properties and photodynamic therapy activity of phenyldiazenyl phenoxy substituted phthalocyanines when incorporated into Pluronic® F127 micelles

Abstract

The synthesis, photophysicochemical properties and photodynamic activity (PDT) of 4(4-phenyldiazenyl) phenoxy substituted indium (III) (InPc) and zinc (ZnPc) phthalocyanines when alone or incorporated into Pluronic® F127 micelles are presented in this study. The InPc exhibited higher singlet oxygen (ΦΔ) at 0.47 compared to the ZnPc at 0.20 in dimethylsulfoxide. The ΦΔ values in the presence of Pluronic® F127 and in water, were 0.32 for InPc and 0.09 for ZnPc. The triplet quantum yields (ΦT) were 0.92 for InPc and 0.32 for ZnPc in DMSO. The PDT activity followed the same trend as the singlet oxygen quantum yields. At the highest concentration, InPc in Pluronic® F127 gave 22% cell viability compared to 34% for complex ZnPc. The partition coefficient Kp values were determined using the water and octanol system. InPc had a larger Kp suggesting that it is more likely to be taken up by the cancer cells, hence it exhibited better PDT activity.