Designed synthesis of prussian blue@Cu-doped zinc phosphate nanocomposites for chemo/chemodynamic/photothermal combined cancer therapy

Designing a multifunctional nanoplatform that combines multiple treatments has emerged as an innovative cancer treatment strategy. A simple and clear route is put forward to develop Cu2+-doped zinc phosphate coated prussian blue nanoparticles (designated as PB@Cu2+/ZnP NPs) integrating tri-modal therapy (chemo, chemodynamic and photothermal therapy) for maximizing anti-tumor efficacy. The obtained PB@Cu2+/ZnP NPs possess drug loading capacity due to the mesoporous structure present in the Cu2+-doped ZnP shell. In addition, the Cu2+-doped ZnP shell can gradually degrade in response to the mildly acidic tumor microenvironment to release DOX and Cu2+, where the released drug plays the role of chemotherapy agent and the Cu2+ can react with intracellular glutathione to achieve a Cu-mediated Fenton-like reaction for chemodynamic therapy. Moreover, under laser irradiation, the heat garnered by the photothermal conversion of PB can be applied for photothermal therapy and enhance the generation of toxic OH as well as the amount of DOX released, further boosting chemo- and chemodynamic therapy to realize a combined therapy. Importantly, the PB@Cu2+/ZnP NPs effectively limit the growth of tumors via the coordinated action of chemo/chemodynamic/photothermal therapy and no noticeable systematic toxicity can be found in mice. Taken together, the PB@Cu2+/ZnP NPs can act as a prospective therapeutic nanoplatform for multi-modal therapy of tumors.