NIR-II driven photocatalytic hydrogen peroxide-supply on metallic copper-nickel selenide (Cu-Ni 0.85 Se) nanoparticle for synergistic therapy.

Currently, finite intratumoral H2 O2 content has restricted the efficacy of chemodynamic therapy (CDT). Here, Cu-Ni0.85 Se@PEG nanoparticles are constructed to display intracellular NIR-II photocatalytic H2 O2 supplement. The formation mechanism is explored to discover that H2 O2 generation is dominated by photo-excited electrons and dissolved O2 via a typical sequential single-electron transfer process. Both density functional theory calculation and experimental data confirm its metallic feature that endows the great NIR-II absorption and photothermal conversion efficiency (59.6 %, 1064 nm). Furthermore, the photothermal-assisting consecutive interband and intraband transition in metallic catalyst contributes to the high redox capacity and efficient separation/transfer ability of photo-generated charges, boosting H2 O2 production under 1064 nm laser irradiation. In addition, Cu-Ni0.85 Se@PEG possess mimic peroxidase and catalase activity, leading to in-situ H2 O2 activation to produce ∙OH and O2 for the enhanced CDT and hypoxia relief. What's more, the nanomaterials reveal novel biodegradation that is derived from oxidation from insolvable selenide into soluble selenate, resulting in elimination via feces and urine within 2 weeks. Synergistic CDT and photothermal therapy (PTT) further lead to great tumor inhibition and immune response for anti-tumor. The antitumor mechanism and the potential biological process also are investigated by high-throughput sequencing of expressed transcripts (RNAseq). The great treatment performance is responsible for the regulation of related oxidative stress and stimulus genes to induce organelle (mitochondrial) and membrane dysfunction. Besides, the synergistic therapy also can efficiently evoke immune response to further fight against tumor.