Synergistic Anticancer Therapy by Ovalbumin Encapsulation-Enabled Tandem Reactive Oxygen Species Generation

Abstract

The anticancer efficacy of photodynamic therapy (PDT) is limited due to the hypoxic features of solid tumors. We report synergistic PDT/chemotherapy with integrated tandem Fenton reactions mediated by ovalbumin encapsulation for improved in vivo anticancer therapy via an enhanced reactive oxygen species (ROS) generation mechanism. O2.− produced by the PDT is converted to H2O2 by superoxide dismutase, followed by the transformation of H2O2 to the highly toxic .OH via Fenton reactions by Fe2+ originating from the dissolution of co-loaded Fe3O4 nanoparticles. The PDT process further facilitates the endosomal/lysosomal escape of the active agents and enhances their intracellular delivery to the nucleus—even for drug-resistant cells. Cisplatin generates O2.− in the presence of nicotinamide adenine dinucleotide phosphate oxidase and thereby improves the treatment efficiency by serving as an additional O2.− source for production of .OH radicals. Improved anticancer efficiency is achieved under both hypoxic and normoxic conditions.