HO self-sufficient nanoplatform based on CeO QDs decorated MgO nanosheet for amplified chemodynamic therapy.

Chemodynamic therapy (CDT), which employs Fenton/Fenton-like agents to decompose hydrogen peroxide (HO) into toxic hydroxyl radical (•OH) to induce cancer cell apoptosis and necrosis, holds great promise in tumor therapy due to its high selectivity. Nevertheless, its efficiency is impaired by the insufficient intracellular HO concentration and/or the insensitive response of Fenton/Fenton-like agents to the slightly acid tumor microenvironment (pH∼7.0-6.5). Herein, we develop a novel CDT reagent based on CeO quantum dot (QD) decorated MgO nanosheets engineered with cascade reactions to boost the intracellular HO level and high pH-activated (pH = 6.5) characteristic for an enhanced CDT. Under the tumor microenvironment (pH = 6.5), MgO nanosheets that are highly reactive can react with HO to produce nontoxic Mg and abundant HO, boosting the intracellular HO level. The self-generated HO is subsequently converted into •OH by CeO QD, which is served as a relatively high pH-activated (pH = 6.5) Fenton-like agent. The sufficient intracellular HO supply and sensitive response to the slightly acid tumor sites significantly improve the Fenton reaction, leading to the excellent in vivo CDT results with tumor growth inhibition effect. Our work presents a distinctive paradigm for self-boosting CDT efficacy.