New phthalocyanine photosensitizers for photodynamic therapy.

Six new aluminum and silicon phthalocyanines have been synthesized and their photocytotoxicity toward V79 cells has been studied. The compounds that have been prepared are: A1PcOSi(CH3)2(CH2)3N(CH3)2, I; A1Pc-OSi(CH3)2(CH2)3N(CH3)3+I-, II; CH3SiPcOSi(CH3)2(CH2)3N(CH3)2, III; HOSiPcOSi(CH3)2(CH2)3N(CH3)2, IV; HOSiPcOSi(CH3)2(CH2)3N(CH3)3+I-, V; and SiPc[OSi(CH3)2(CH2)3N(CH3)3+I-]2, VI. Relative growth delay values for compounds I-VI and relative cytotoxicity values for compounds I, II, IV, V and VI have been determined. Compounds I and II have been shown to be comparable in photocytotoxicity to what is presumed to be A1PcOH.xH2O, and compound IV has been shown to have greater activity. The classes of compounds to which these six compounds belong appear to have potential for photodynamic therapy.