Sonodynamic antitumour effect of chloroaluminum phthalocyanine tetrasulfonate on murine solid tumour

The sonodynamically induced antitumour effect of chloroaluminum phthalocyanine tetrasulfonate (AlPcTS) was evaluated on subcutaneously implanted colon 26 carcinoma. A time of 24 h after the administration of AlPcTS was chosen for the ultrasonic exposure, based on the analysis of the AlPcTS concentrations in the tumour, plasma, skin and muscle. The pharmacokinetic analysis showed much faster clearance of AlPcTS than photofrin II from the body, which can be an advantage in view of their potential adverse effects. At an AlPcTS dose not less than 2.5 mg kg(-1) and at a free-field ultrasonic intensity not less than 3 W cm(-2), the synergistic effect between AlPcTS administration and ultrasonic exposure on the tumour growth inhibition was significant. The ultrasonic intensity showed a relatively sharp threshold for the synergistic antitumour effect, which is typical for an ultrasonic effect mediated by acoustic cavitation. These results suggest that AlPcTS is a potential sonosensitizer for sonodynamic treatment of solid tumours.