Platelet\nMembrane-Camouflaged Copper Doped CaO<sub>2</sub> Biomimetic Nanomedicines\nfor Breast Cancer Combination Treatment

Breast cancer (BC) is the most frequently diagnosed cancer\nin women\nworldwide. Chemodynamic therapy (CDT), photothermal therapy (PTT),\nand ion interference therapy (IIT), used in combination, represent\na common treatment. In this study, platelet membrane-camouflaged\ncopper-doped CaO<sub>2</sub> biomimetic nanomedicines have been developed\nfor breast cancer treatments. Copper-doped CaO<sub>2</sub> nanoparticles\nwere first coated by polydopamine (PDA) and subsequently camouflaged\nby platelet membrane (PM) to form platelet membrane-camouflaged copper\ndoped CaO<sub>2</sub> biomimetic nanomedicines (Cu-CaO<sub>2</sub>@PDA/PM). The as-fabricated Cu-CaO<sub>2</sub>@PDA/PM multifunctional\nnanomedicines could decompose within the tumor microenvironment to\nrelease Ca<sup>2+</sup> for ion interference therapy, and the generated\nH<sub>2</sub>O<sub>2</sub> could perform a Fenton-like reaction with\nthe assistance of loaded copper ions to produce ·OH, thus realizing\nchemodynamic therapy. In addition, the copper ions could also consume\nglutathione and weaken its ability to scavenge reactive oxygen species,\nwhich was conducive to amplifying the effect of oxidative stress.\nThe coating of the polydopamine layer could achieve local hyperthermia\nof the tumor site, and the surface modification of the platelet membrane\ncould enhance the targeting and biocompatibility of nanomedicines. <i>In vivo</i> and <i>in vitro</i> tests demonstrated\nthat the developed Cu-CaO<sub>2</sub>@PDA/PM biomimetic nanomedicines\noffer a promising biomimetic nanoplatform for efficient multimodal\ncombination therapy for breast cancer.