Self-supplied H₂O₂ Nanozymes Enhance Tumor Catalytic Therapy

Nanozyme is a new type of mimetic enzyme,which is different from natural enzymes and traditional mimic enzymes.It has both the unique physical and chemical properties of nanomaterials and the catalytic activity of enzymes.Due to its high stability,high catalytic activity and low cost,it makes it suitable for biomedicine.Research in the fields of biotechnology,biosensors,immunoassays,and cancer treatment has received widespread attention.With the in-depth study of the work of nanozymes,the nano-characteristics of nanozymes allow their enzymatic activities to improve their specificity and catalytic activity through changes in size and morphology,chemical doping and surface modification.In addition,in the latest research on catalytic chemistry that promotes the development of nanomedicine,the unique physicochemical properties of nanozymes have given them excellent catalytic performance in applications such as cancer treatment.For example,in terms of tumor treatment,when ferromagnetic nanoparticles are used as drug carriers to contact cancer cells in vivo,if hydrogen peroxide is present,it will catalyze H₂O₂ to generate free radicals and effectively induce apoptosis,but endogenous H₂O₂ is not sufficient To achieve satisfactory anti-cancer efficacy.Therefore,how to improve the therapeutic efficiency of nanozymes in vivo is still a challenge.In this paper,we prepared a nanozyme platform(Fe@Fe₃O₄@Cu_2-x-x S,MNPs)with peroxidase activity,and introducedβ-Lapachone（La）on the surface of MNPs through hydrophobic-hydrophobic interaction.Drug-loaded nanozymes LaMNPs were obtained to promote nanozyme-mediated tumor treatment by generating H₂O₂ in situ in cells.In the acidic microenvironment of tumors,La released by LaMNPs enters the cells,and forms a redox cycle under the action of quinone oxidoreductase（NQO1）and intracellular oxygen molecules in the cancer cells,producing superoxide and H₂O₂,iron The copper and copper composites have high Fenton and Fenton-like catalytic activity,which can effectively catalyze H₂O₂ to generate hydroxyl radicals（·OH）,thereby effectively inducing cancer cell apoptosis.In a 4T1 mouse tumor model,LaMNPs nanozymes showed significant inhibitory properties on tumors.