Synthesis of axially disubstituted quaternized silicon phthalocyanines as a promising photosensitizer for photodynamic treatment of HCT-116, A549 and SH-SY5Y cancer cell lines

In this study, novel silicon(IV) phthalocyanines axially disubstituted with bis[(4-{3-[3-(dimethylamino)phenoxy]propoxy}phenyl)metoxy], bis[(4-{3-[3-(diethylamino)phenoxy]propoxy}phenyl)metoxy] groups and their quaternized derivatives have been synthesized and characterized. Then, their supercoiled pBR322 plasmid DNA cleavage properties were investigated using agarose gel electrophoresis. In vitro PDT effects of Si-3a and Si-4a were investigated using MTT cell viability assay against HCT-116, A549 and SH-SY5Y cell lines. Si-3a and Si-4a did not show cleavage effects on increasing concentrations in the dark but both compounds showed cleavage activities with irradiation for 30 and 60 min. MTT cell viability assay indicated that Si-4a had cytotoxic effect in a concentration-dependent manner on HCT-116 cell line but it did not show a statistical difference compared to phototoxicity. Otherwise, Si-3a and Si-4a had significant phototoxic effects when compared to cytotoxic effects against A549 and SH-SY5Y. The results suggested that Si-3a and Si-4a showed better cell death against SH-SY5Y than other cell lines with irradiation.