H₂O₂ Self-Supplementing and GSH-Depleting Nanoreactors Based on MoO_3–x@Fe₃O₄-GOD-PVP for Photothermally Reinforced Nanocatalytic Cancer Therapy at the Second Near-Infrared Biowindow

Abstract

Nanocatalytic therapy is an emerging strategy for combating various malignant tumors, which is limited by acid/H 2 O 2 deficiency and overexpressed glutathione (GSH). Herein, the versatile MoO 3−x @Fe 3 O 4 -GOD-PVP (MFGP) nanoreactors were developed to overcome the limitations of nanocatalytic therapy. First, MoO 3−x nanoflakes were loaded with Fe 3 O 4 nanozymes via electrostatic self-assembly and then decorated with glucose oxidase (GOD) and polyvinylpyrrolidone (PVP). At the tumor microenvironment (TME), nanocatalytic therapy can be performed by the nanoreactors triggering a sequence of catalytic reactions. The hydroxyl radicals (•OH) generated by Fe 3 O 4 nanozymes triggering the Fenton reaction can kill cancer cells. GOD could not only consume the glucose of the TME to starve the tumor but also in situ generate gluconic acid/H 2 O 2 resulting in sustainable •OH production. In addition, overexpressed GSH, an antioxidant of cancer cells, would be effectively consumed via Mo triggering redox reactions. Importantly, due to the strong second near-infrared (NIR-II) absorption of MoO 3−x nanoflakes, MFGP possessed an excellent photothermal property (photothermal conversion efficiency of 49.9%). The generated hyperthermia by MFGP can simultaneously enhance the Fenton reaction efficiency, GOD catalytic reaction, and GSH depletion. Extensive biomedical evaluations demonstrated the desirable tumor suppression effect based on hyperthermiaaugmented nanocatalytic therapy. Overall, this work paves the way to the exploration of tumor nanocatalytic therapy.

An Injectable Black Phosphorus Hydrogel for Rapid Tooth Extraction Socket Healing

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Iron/Molybdenum Sulfide Nanozyme Cocatalytic Fenton Reaction for Photothermal/Chemodynamic Efficient Wound Healing

“…Fortunately, over the past few years, the rapid development of nanomaterials has propelled significant progress in antimicrobial therapy. − In general, nanozymes have a wide range of antibacterial activity and minimal toxicity and do not induce drug resistance . By specific catalytic reaction, they can produce reactive oxygen species (ROS) including hydroxyl radicals (•OH), which have been scientifically proven to exhibit bactericidal effects by damaging bacterial cell membranes, DNA, proteins, and other vital cellular components in previous research. ,, Specifically, nanozymes show peroxidase (POD)-like activity and can selectively promote hydrogen peroxide (H 2 O 2 ) to convert into extremely noxious ROS, − which was utilized to target and assault the membranes of bacteria at infection sites with low acidity for antibacterial chemodynamic therapy (CDT), thus leading to cellular apoptosis, necrosis, and finally bacterial eradication. − Traditional CDT provides •OH through Fenton/Fenton-like reactions, , involving a complex chemical reaction between iron (Fe) and H 2 O 2 . During this process, highly catalytic Fe 2+ reacts with H 2 O 2 to generate •OH for eradicating bacteria, along with the production of Fe 3+ with low Fenton catalytic activity.…”

Cobalt Single-Atom Nanozyme Co-Administration with Ascorbic Acid Enables Redox Imbalance for Tumor Catalytic Ablation

“…Glutathione, as the most abundant antioxidant manufactured by the human body, can effectively scavenge ROS, such as superoxide and hydroxyl radicals. − ROS-based therapy is rendered ineffective by the extreme glutathione (GSH) levels found within tumors; , therefore, the depletion of GSH is favorable for ROS accumulation in cancer cells and in turn affects the proliferation and function of cancer cells. Many researchers have engineered numerous nanomaterials by simultaneously providing therapeutic components and GSH-depleting agents to boost not only traditional radiotherapy − but also multifarious emerging treatment, including sonodynamic therapy (SDT) and photodynamic therapy (PDT). , As a paradigm, Tan and co-workers reported the fabrication of a smart Chlorin e6 (Ce6)-manganese dioxide (MnO 2 ) nano drug delivery system for a highly efficient PDT through MnO 2 nanosheets enhancing the delivery efficiency and reacting with high concentrations of GSH, thus enhancing the PDT effect. The Liu group developed CaCO 3 -based nanomedicine for synergistic oxidative stress amplification via intracellular Ca 2+ -overloading-induced mitochondrial damage, GSH depletion, and sonodynamic treatment (SDT) .…”