Chemodynamic therapy (CDT) is well acknowledged as potent reactive oxygen species (ROS)-mediated anticancer strategy. Especially, the study about labile iron pool (LIP) as endogenous ferrous catalyzer has paved the way for future CDT development. However, limited H2O2 expression, mild acidity, reduced glutathione (GSH) ablation of ROS, etc., all require employing alternate peroxo-complex to achieve enhanced CDT effect. As a non-Fenton-type substrate, artesunate (ART) has been utilized as a source of free radicals through decomposition of endoperoxide bridges catalyzed by ferrous ions, nonetheless, the non-tumor-specific delivery, inferior pharmacokinetics, and hydrophobic nature minimize the efficacy of ART in physiological systems. Herein, we devise a PPA nanoamplifier by conjugating ART with PEG-functionalized Pd@Pt nanoplates (PP NPs) to form ester linkage, ensuring specific intratumoral esterase-responsive ART release. Significantly, the PPA nanoamplifier combines the in situ decomposition of ART's endoperoxide bridges by Fe2+ to superoxide anions (O2·-) and peroxidase (POD)-like enzymatic catalysis of endogenous H2O2 by PP to hydroxyl radicals (·OH), thus achieving amplified ROS-mediated tumor therapy. Besides, PPA displays GSH destruction potential, thereby protecting ROS from the cleavage by GSH oxidation. In addition, the strong absorption of PPA in near-infrared (NIR) region also endows PPA with photoacoustic property to realize imaging-guided CDT. In short, by taking advantages of the high enrichment and esterase- responsive drug release at tumor sites, PPA amplified ROS signals via dual pathways, killing tumor cells in vitro and inhibiting tumor growth in vivo, thereby realizing high-efficiency non-Fenton CDT. We believe our novel anti-tumor strategy based on PPA will broaden the future of ROS-mediated tumor-targeted therapy.
Publications
Article type
Year
Research Article
Issue
Nano Research 2022, 15(2): 907-918
Published: 25 June 2021
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