Distribution and photodynamic effect of zinc phthalocyanine disulfonate in nude mice bearing mammary carcinoma

The distribution study of zinc phthalocyanine disulfonate (ZnPcS2) in nude mice bearing mammary carcinoma (T50/80) revealed a rapid uptake of the dye by tumor. In experimental photodynamic therapy (PDT), the tumors were exposed to laser radiation (670 nm, 100 mW/cm2, 150 J/ /cm2) after intravenous administration of ZnPcS2 in saline. The results showed the maximum tumor destruction to be achieved for the time interval between injection of the drug (2 mg/kg) and exposure to laser light of 5 min, while a significantly less damage was observed when the time interval was 24 h (p < 0.0001). The degree of damage produced by the treatment was monitored in vivo by means of noninvasive NMR-imaging and subsequently confirmed histologically.