Bleomycin enhances the efficacy of sonodynamic therapy using aluminum phthalocyanine disulfonate

• Our in vitro study showed that sonodynamic therapy with bleomycin had a significantly greater cytotoxic effect on Colon-26 cells compared to sonodynamic therapy alone.
• In an in vivo study, tumor growth was inhibited to a greater extent by combined sonodynamic therapy and bleomycin administration compared to sonodynamic therapy alone.
• Bleomycin could improve the efficacy of sonodynamic therapy.
• Sonodynamic therapy with bleomycin might provide a novel noninvasive treatment for deep-seated tumors.

Sonodynamic therapy (SDT), or ultrasound combined with sonosensitization, is a promising approach because it is noninvasive and penetrates deeper than light does in photodynamic therapy. We examined whether bleomycin (BLM) could improve the efficacy of SDT. We performed an in vitro study using Colon-26 cells, which are derived from mouse colon cancer. SDT with BLM was significantly more cytotoxic than SDT alone both in vitro and in vivo. We also observed an ultrasound intensity-dependent cytotoxic effect of SDT with BLM. These findings suggest that SDT with BLM might provide a novel noninvasive treatment for deep-seated tumors.