Sonochemical activation of hematoporphyrin: a potential modality for cancer treatment

In-vitro and in-vivo studies demonstrate the antitumor effect of hematoporphyrin sonochemically activated by ultrasound irradiation. Tumor cell suspensions with and without hematoporphyrin (Hp) are irradiated by continuous-wave ultrasound. Ultrasound cell damage with Hp is significantly greater than that without Hp, while no cell damage by Hp alone was detected. Growth of tumors implanted in mice is stopped by the ultrasound irradiation after Hp administration. Because the cell-damage enhancement by Hp is suppressed by adding histidine to the suspension but not by adding mannitol, the enhancement is most likely due to sonochemical generation of singlet oxygen