Ultrasound-Induced Reactive Oxygen Species Mediated Therapy and Imaging Using a Fenton Reaction Activable Polymersome

Ultrasound techniques have been extensively employed for diagnostic purposes. Because of its features of low cost, easy access, and noninvasive real-time imaging, toward clinical practice it is highly anticipated to simply use diagnostic ultrasound to concurrently perform imaging and therapy. We report a H₂O₂-filled polymersome to display echogenic reflectivity and reactive oxygen species-mediated cancer therapy simply triggered by the microultrasound diagnostic system accompanied by MR imaging. Instead of filling common perfluorocarbons, the encapsulation of H₂O₂ in H₂O₂/Fe₃O₄-PLGA polymersome provides O₂ as the echogenic source and ^•OH as the therapeutic element. On exposure to ultrasound, the polymersome can be easily disrupted to yield ^•OH through the Fenton reaction by reaction of H₂O₂ and Fe₃O₄. We showed that malignant tumors can be completely removed in a nonthermal process.