Wintersweet-like Nanohybrids of Titanium-doped Cerium Vanadate Loaded with Polypyrrole for Tumor Theranostic.

Abstract

Compromises between enhanced on-targeting reactivity and precise real-time monitoring in the tumor microenvironment (TME) are the main roadblocks for catalytic cancer therapy. The hallmark of a high level of hydrogen peroxide (H₂O₂) and acidic extracellular environment of the hypoxia solid tumor can underpin therapeutic and tracking performance. Herein, this work provides an activatable wintersweet-like nanohybrid consisting of titanium (Ti) doped cerium vanadate nanorods with the modification of polypyrrole (PPy) nanoparticles (CeVO₄-Ti@PPy) for combinatorial therapies of breast carcinoma. The Ti dopants in the size-controllable CeVO₄ nanorods lower the energy barrier (0.5 eV) of the rate-determining steps and elaborate peroxidase-like (POD-like) activities to improve the generation of toxic hydroxyl radical (·OH) according to the density functional theory (DFT) calculation. The multiple enzyme-like activities, including the intrinsic glutathione peroxidase (GPx) and catalase (CAT), achieve a record-high therapeutic efficiency. Coupling this oxidative stress with the photothermal effects of PPy enables enhanced catalytic tumor necrosis. The exterior PPy heterogeneous structure can be further doped with protons in the local acidic environment to intensify photoacoustic signals, allowing the non-invasive accurate tracking of tumors. The theranostic performance displayed negligible attenuated signals in near-infrared (NIR) windows. This organic-inorganic nanohybrid with a heterogeneous structure provides the potential to improve the overall outcomes of catalytic therapy.