Ultrasmall copper-based nanoplatforms for NIR-II light-triggered photothermal/ photodynamic and amplified nanozyme catalytic therapy of hypoxic tumor

A NIR-II light-actuated multifunctional nanoplatform based on ultrasmall CuCo2S4 and Pt nanoparticles is developed for photothermal enhanced nanozyme catalytic and photodynamic therapy. [Display omitted] •CuCo2S4-Pt-PEG nanocomposites is ultrasmall, which facilitates cellular uptake, and improves the anticancer efficiency.•The nanocomposites have a high photothermal conversion efficiency of 78.46%, and can enhance nanozyme catalytic activities.•The CAT nanozyme activities of Pt enables CuCo2S4-Pt-PEG to produce more O2, and amplify its photodynamic properties.•CuCo2S4-Pt-PEG can stimulate the immune system to elicit immune response, and inhibited tumor metastasis. The clinical applications of the photothermal therapy (PTT) and photodynamic therapy (PDT) are restricted by the limited tissue penetration depth of excitation light, while the enzyme catalysis therapy is hindered on account of the low treatment efficiency. Herein, we modify artificial nanozyme Pt nanoparticles on the surface of CuCo2S4 nanoparticles to prepare ultrasmall copper-based ternary bimetallic chalcogenides CuCo2S4-Pt-PEG nanocomposites for PTT/PDT/enzyme catalysis synergistic therapy. The as-fabricated CuCo2S4-Pt-PEG nanocomposites display peroxidase (POD)-like and catalase (CAT)-like activities, which can catalyze hydrogen peroxide to emerge highly toxic hydroxyl radicals and oxygen, respectively. The integration of Pt nanozyme significantly improves the POD-like and CAT-like activity of CuCo2S4 −PEG that can produce more hydroxyl radicals and oxygen to improve the effects of PDT. Furthermore, the nanocomposites exhibit outstanding photothermal properties derived from the enhanced photothermal conversion efficiency (η = 78.46 %) exposed to 1064 nm NIR-II light irradiation with a low power density (0.8 W cm−2). In particular, the photothermal performance of CuCo2S4-Pt-PEG significantly enhances the enzyme-like activity. Additionally, the T1-weighted magnetic resonance and photoacoustic imaging endow CuCo2S4-Pt-PEG with the advantages of guiding the treatment process. The synergistic treatment demonstrates significant anticancer treatment efficiency while also elicits immune response that suppressed metastasis. This study could further promote the application of ternary bimetallic chalcogenides in cancer diagnosis and treatment.