LAUSR

The clinical application of photothermal therapy (PTT) is severely limited by the tissue penetration depth of excitation light, and enzyme therapy is hampered by its low therapeutic efficiency. As a two-dimensional ultrathin nanosheet with high absorbance in the near-infrared-II (NIR-II) region, the titanium carbide (Ti3C2) nanosheet can be used as a substrate to anchor functional components, like nanozymes and nanodrugs. Here, we decorate Pt artificial nanozymes on the Ti3C2 nanosheets to synthesize Ti-based MXene nanocomposites (Ti3C2Tx-Pt-PEG). In the tumor microenvironment, the Pt nanoparticles exhibit peroxidase-like (POD-like) activity, which can in situ catalyze hydrogen peroxide to generate hydroxyl radicals (•OH) to induce cell apoptosis and necrosis. Meanwhile, the composite shows a desirable photothermal effect upon NIR-II light irradiation with a low power density (0.75 W cm-2). Especially, the POD-like activity is significantly enhanced by the elevated temperature arising from the photothermal effect of Ti3C2Tx. Therefore, satisfactory synergistic PTT/enzyme therapy has been accomplished, accompanied by an applicable photoacoustic imaging capability to monitor and guide the therapeutic process. This work may provide an approach for hyperthermia-amplified nanozyme catalytic therapy, especially based on metal catalysts and MXene nanocomposites.