Mo2 C-Derived Polyoxometalate for NIR-II Photoacoustic Imaging-Guided Chemodynamic/Photothermal Synergistic Therapy

Abstract

To overcome the current limitations of chemodynamic therapy (CDT), a Mo₂ C-derived polyoxometalate (POM) is readily synthesized as a new CDT agent. It permits synergistic chemodynamic and photothermal therapy operating in the second near-infrared (NIR-II) biological transparent window for deep tissue penetration. POM aggregated in an acidic tumor micro-environment (TME) whereby enables specific tumor targeting. In addition to the strong ability to produce singlet oxygen (¹ O₂ ) presumably via Russell mechanism, its excellent photothermal conversion enhances the CDT effect, offers additional tumor ablation modality, and permits NIR-II photoacoustic imaging. Benefitting from the reversible redox property of molybdenum, the theranostics based on POM can escape from the antioxidant defense system. Moreover, combining the specific responsiveness to TME and localized laser irradiation, side-effects shall be largely avoided.

Keywords: NIR-II; chemodynamic therapy; molybdenum polyoxometalate; photoacoustic imaging; photothermal therapy.