A self-assembled Ru nanozyme with H2O2-activated oxygenation for NIR-II photoacoustic imaging-guided photothermal/photodynamic therapy

Abstract

The characteristic hypoxia of solid tumors seriously reduced the treatment efficacy of oxygen-dependent photodynamic therapy (PDT). Herein, an oxygen nanogenerator, comprising Ru-based nanomaterials, CS–DA@Ru nanoparticles (NPs), has been constructed to relieve tumor hypoxia along with photodynamic/photothermal therapy for efficient tumor eradication. CS–DA@Ru NPs possess targeting ability and act as catalase-mimic nanozymes to decompose endogenous hydrogen peroxide in the tumor to produce O₂. The broad absorbance of CS–DA@Ru NPs in the second near-infrared (NIR-II) region enabled them to possess good photothermal properties and photoacoustic (PA) imaging ability. CS–DA@Ru NPs could generate enough hyperthermia and enormous amounts of ¹O₂ under NIR-II laser irradiation. Specifically, CS–DA@Ru NPs exhibit catalase-like activity as well as a significantly augmented antitumor efficacy through synergistic PTT/PDT guided by NIR-II PA imaging in both cells and in vivo experiments. This work will advance the development of noble metal nanozymes in enhancing the efficacy of O₂-dependent antitumor modalities.