Engineered Biomimetic Copper Sulfide Nanozyme Mediates "Don't Eat Me" Signaling for Photothermal and Chemodynamic Precision Therapies of Breast Cancer.

The rapid development of nanomedicine has brought hope and confidence to the precise treatment of tumors. However, the efficacy of nanoparticle-mediated therapy is severely limited due to phagocytosis and clearance by macrophages. CD47 is a well-documented ″don't eat me″ signaling molecule that binds to the SIRPα receptor on the macrophage surface, inhibiting the phagocytic behavior of the macrophages. In this study, CD47-overexpressing cancer cell membranes were used to coat hollow copper sulfide nanoparticles. The nanoparticles were shown to have an extended circulatory half-life and to actively target breast cancer, leading to increased accumulation in the tumor tissue. An excellent photothermal therapeutic effect was produced by near-infrared laser irradiation. At the same time, β-lapachone within the nanoparticles generated large amounts of hydrogen peroxide in the tumor environment, which was then catalyzed by the copper sulfide nanozyme to cytotoxic hydroxyl radicals, exerting a chemodynamic therapeutic effect. This engineered biomimetic nanozyme, through the mediation of the ″don't eat me″ signal, achieved both photothermal and chemodynamic precision treatments of breast cancer, creating a new mode of safe and effective tumor treatment.