Nanozymes With SOD-like Activity

Introduction

Nanozymes with superoxide dismutase (SOD)-like activity are selected as favorable tools to anti-oxidation and anti-aging since they could transform superoxide anion radicals into H₂O₂ and O₂. In addition, they have the advantages of high stability, easy preparation, low cost, and easy large-scale production. They overcome the limitations of natural enzymes and show great application potential in inflammatory bowel disease (IBD) therapy and alleviating endotoxemia.

Study On Catalytic Mechanism

Regarding the catalytic mechanism of nanozymes with SOD-like activity, Wang et al. carried out in-depth research. They proposed a polished catalytic cycle mechanism for CeO₂ nanoparticles as SOD mimics. Specifically, as shown in Figure 1, after the coadsorption of HO₂· onto the surface of CeO₂, the intermediate was formed. Then, the reaction between the intermediate and another HO₂· radicals could release H₂O₂ and O₂, with the CeO₂ nanoparticles restored to the initial state^[1]. In addition, with the assistance of rigorous density functional theory and microkinetic modeling, Guo et al. explored two possible catalytic mechanisms (i.e., Langmuir-Hinshelwood (LH) mechanism and Eley-Rideal (ER) mechanism) for Fe₃O₄ nanozymes with SOD-like activity. They identified that the LH mechanism was the energetically most favorable pathway. The LH mechanism started from the coadsorption of two HO₂· species. They were absorbed on the surface of Fe₃O₄ to from the intermediate with OOH* and HOO* species (* refers to an adsorption site). Then, the O–H bond of OOH* species was split and the H atom further migrated to combine with the nearby O atom of HOO* to form a H₂O₂ molecule. An O₂ molecule was then formed and adsorbed at the Fe site. Finally, the H₂O₂ and O₂ molecule were desorbed from the surface^[2].

Fig.1 Catalytic mechanism of CeO₂ nanoparticles with SOD-like activity.

Applications

The nanozymes with SOD-like activity can be used for inflammatory bowel disease (IBD) therapy and alleviating endotoxemia.

• IBD therapy. Reactive oxygen species (ROS) are highly reactive oxygen metabolites produced in organisms through endogenous pathways and environmental stimulation, and are involved in the pathogenesis of IBD. Nanozymes with SOD-like activity can scavenge excess ROS in the inflamed colon, therefore they can be used in the treatment of IBD. For example, Ma et al. synthesized carbon dots nanozymes with SOD-like activity. In IBD mice models, the carbon dots nanozymes could restore damaged epithelial cells and colon length, reduce the expression of pro-inflammatory cytokines, and thus effectively alleviated colon inflammation^[3].

Fig.2 Carbon dots nanozymes with SOD-like activity used for IBD therapy.

• Alleviating endotoxemia. Nanozymes with SOD-like activity can functionally and structurally mimic the antioxidant SOD to alleviate endotoxemia. For example, Ren's group and Qu's group fabricated nanozymes with SOD-like activity called Cu-TCPP MOF dots (CTMDs). They can effectively scavenge reactive oxygen free radicals and have renal enrichment and clearance capabilities, thereby alleviating endotoxemia^[4].

Fig.3 CTMDs serves as nanozymes with SOD-like activity used for alleviating endotoxemia.

Alfa Chemistry offers a series of nanozymes with SOD-like activity, which can be used for IBD therapy and alleviating endotoxemia. You can click on our product list for a detailed view. At the same time, we also offer product customization according to customer's detailed requirements. If you are interested in our products or have any questions or needs, please feel free to contact us. We will be happy to provide you with support and services.

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