Involvement of hydrogen peroxide in sonodynamical effect with sinoporphyrin sodium in hypoxic situation

Sonodynamic therapy (SDT) represents a noninvasive therapeutic method via the activation of certain chemical sensitizers using low-intensity ultrasound to generate various reactive oxygen species (ROS). In this work, we conducted systematic experiments to evaluate the production of hydrogen peroxide (H₂O₂) in sinoporphyrin sodium (DVDMS) mediated SDT (DVDMS-SDT). We found that the fluorescence intensities of H₂O₂-specific probe BES-H₂O₂ and Amplex Red increased significantly exposure to DVDMS-SDT while decreased with the introduction of catalase (H₂O₂ scavenger), indicating the production of H₂O₂. And the fluorescence intensity of H₂O₂ susceptible probes were positively correlated with DVDMS concentration, ultrasound intensity and irradiation time. Under the same molarity concentration, DVDMS has advantages over proto-porphyrin IX (PpIX) and hemoporrin monomethyl ether (HMME) in H₂O₂ production, indicating that the yield of H₂O₂ depends on the properties of sensitizer. More importantly, DVDMS-SDT is involved in the process of H₂O₂ even in the oxygen-free condition, showing its greater superiority for the treatment of tumor under hypoxia environment.