Engineering Mn3O4 shell on PdAu nanosheets for enhanced MRI diagnosis and efficient photothermal/chemodynamic therapy of tumor and pulmonary metastasis

Abstract

The prospects for oncological therapeutics are greatly expanded by the development of engineered nanodrugs that seamlessly integrate diagnostic and therapeutic functions into a single platform. Herein, we introduce an intelligent probe constructed by engineering a Mn3O4 shell onto two-dimensional PdAu nanosheets, designed to enable magnetic resonance imaging based diagnosis while simultaneously delivering synergistic chemodynamic and photothermal therapy. The Mn3O4 shell is specifically engineered to degrade under mildly acidic and reductive intracellular conditions, releasing Mn2+ ions that bind to surrounding proteins, thereby markedly enhancing longitudinal relaxivity and facilitating specific tumor diagnosis, including the detection of early pulmonary metastases as small as 0.6 mm. In parallel, Mn2+ ions initiate chemodynamic therapy via Fenton-like reactions, catalyzing the conversion of H2O2 into cytotoxic ·OH radicals. Moreover, the diagnostic imaging provides precise guidance for near-infrared irradiation, enabling targeted photothermal therapy and achieving synergistic therapeutic effects against both subcutaneous tumors and pulmonary metastases. Collectively, this work establishes a new paradigm in nanomedicine engineering, integrating precise diagnostic functionality with potent antitumor efficacy.