Construction of Cu/ZIF-67/Prussian Blue Nanostructures with Photothermal-Enhanced Multizyme Activity for Cancer Therapy

Nanozymes that mimic the catalytic reaction of natural enzymes show great prospects for tumor catalytic therapy because they possess the properties of nanomaterials and natural enzymes. However, the therapeutic effect of nanozymes is restricted by the low catalytic efficiency and specific oxidation–reduction systems in the tumor microenvironment (TME), such as overexpressed glutathione (GSH) level. In order to improve the catalytic efficiency, a multifunctional nanozyme, Cu/zeolitic imidazolate framework-67 (ZIF-67)/Prussian blue (PB), was designed through the modification of Prussian blue (PB) on the surface of the copper-doped zeolitic imidazolate framework, which can be used for imaging-guided synergistic therapy with photothermal-enhanced multienzyme-like catalytic therapy and chemotherapy. The doping of Cu2+ provided better glutathione oxidase-like (GPx-like) activity and peroxidase-like (POD-like) activity to deplete GSH and increase the generation of •OH in TME. The modification of PB provided better catalase-like activity (CAT-like) to promote the production of O2 and enhance the multienzyme-like catalytic therapy. In vivo experiments showed a satisfactory anticancer effect. This work thus provided a strategy for designing a type of multifunctional nanozyme for imaging-guided combination therapy.