Sonodynamic Antitumor Effect of Zinc Phthalocyanine Tetrasulfonate on Murine Solid Tumor Colon 26

摘要

In this study, the sonodynamically induced antitumor effect of zinc phthalocyanine tetrasulfonate (ZnPcTS) was evaluated on subcutaneously implanted colon 26 carcinoma. In order to determine the optimum timing for the ultrasonic exposure of the tumor, the time course of ZnPcTS concentrations in the plasma, tumor, muscle and skin were measured and analyzed pharmacokinetically. Antitumor effects were evaluated by the histological observation and tumor growth after the exposure. The timing of two hours after the administration of ZnPcTS was chosen for the ultrasonic exposure, based on the analysis of the ZnPcTS concentrations in the tumor, plasma, skin, and muscle. The destruction of tumor tissue was observed with the ultrasonic treatment in combination with ZnPcTS, while neither the treatment with ZnPcTS alone nor that with ultrasound alone caused any necrosis. At an ZnPcTS dose not less than10 mg/kg and at a free-field ultrasonic intensity not less than 3 W/cm2， the synergistic effect between ZnPcTS administration and ultrasonic exposure on the tumor growth inhibition was significant. The ultrasonic intensity showed a relatively sharp threshold for the synergistic antitumor effect, which is typical for an ultrasonic effect mediated by acoustic cavitation. These results suggest that ZnPcTS is a potential sonosensitizer for sonodynamic treatment of solid tumors.