Construction of Cu/ZIF-67/Prussian\nBlue Nanostructures\nwith Photothermal-Enhanced Multizyme Activity for Cancer Therapy

Nanozymes that mimic the catalytic reaction of natural\nenzymes\nshow great prospects for tumor catalytic therapy because they possess\nthe properties of nanomaterials and natural enzymes. However, the\ntherapeutic effect of nanozymes is restricted by the low catalytic\nefficiency and specific oxidation–reduction systems in the\ntumor microenvironment (TME), such as overexpressed glutathione (GSH)\nlevel. In order to improve the catalytic efficiency, a multifunctional\nnanozyme, Cu/zeolitic imidazolate framework-67 (ZIF-67)/Prussian blue\n(PB), was designed through the modification of Prussian blue (PB)\non the surface of the copper-doped zeolitic imidazolate framework,\nwhich can be used for imaging-guided synergistic therapy with photothermal-enhanced\nmultienzyme-like catalytic therapy and chemotherapy. The doping of\nCu²⁺ provided better glutathione oxidase-like (GPx-like)\nactivity and peroxidase-like (POD-like) activity to deplete GSH and\nincrease the generation of ^•OH in TME. The modification\nof PB provided better catalase-like activity (CAT-like) to promote\nthe production of O₂ and enhance the multienzyme-like catalytic\ntherapy. <i>In vivo</i> experiments showed a satisfactory\nanticancer effect. This work thus provided a strategy for designing\na type of multifunctional nanozyme for imaging-guided combination\ntherapy.