Construction of pH‐Dependent Nanozymes with Oxygen Vacancies as the High‐Efficient Reactive Oxygen Species Scavenger for Oral‐Administrated Anti‐Inflammatory Therapy

Abstract

It is of great significance to eliminate excessive reactive oxygen species (ROS) for treating inflammatory bowel disease (IBD). Herein, for the first time, a novel nanozyme NiCo 2 O 4 @PVP is constructed via a step-by-step strategy. Noticeably, the existence of oxygen vacancy in the NiCo 2 O 4 @PVP is helpful for capturing oxygenated compounds, while both redox couples of Co 3+ /Co 2+ and Ni 3+ /Ni 2+ will offer richer catalytic sites. As expected, the obtained NiCo 2 O 4 @PVP exhibits pH-dependent multiple mimic enzymatic activities. Benefiting from the introduction of polyvinylpyrrolidone (PVP), the NiCo 2 O 4 @PVP possesses good physiological stability and excellent biosafety in stomach and intestines' environment. Meanwhile, the NiCo 2 O 4 @PVP also presents strong scavenging activities to ROS in vitro, including • O 2 − , H 2 O 2 , as well as • OH. Furthermore, a dextran sodium sulfate (DSS)-induced colitis model is established for evaluating the anti-inflammatory activity of NiCo 2 O 4 @PVP in vivo. Based on the size-mediated and charge-mediated mechanisms, the nanozyme can pass through the digestive tract and target the inflamed site for oral-administrated anti-inflammatory therapy. More interestingly, compared with the model group, the expression levels of inflammatory factors (e.g., Interleukin-6 (IL-6), Interleukin-1𝜷 (IL-1𝜷), tumor necrosis factor-𝜶 (TNF-𝜶), and inducible nitric oxide synthase (iNOS)) in colon of mice show a significant decrease after nanozyme intervention, thereby inhibiting the development of IBD. In short, current work provides an alternative therapy for patients suffering from IBD.

Dietary soybeans worsen dextran sodium sulfate-induced colitis by disrupting intestinal ecology

“…The macrophage activity is associated with pathogen clearance, and affects the recovery from inflammation. 37 Here, the regulation of macrophages by bacterial flora is bidirectional. When some bacteria, especially potentially pathogenic bacteria like E. coli , are enriched, apoptosis of macrophages will be caused and inflammation will be intensified.…”

Cold Exposure Induces Intestinal Barrier Damage and Endoplasmic Reticulum Stress in the Colon via the SIRT1/Nrf2 Signaling Pathway

“…Dysfunction of the colonic epithelial barrier can also promote the occurrence and development of colonic inflammation, with pro-inflammatory cytokines such as IL-1β, IL-6 and TNF-α playing a key role in the development of inflammation ( Marafini et al, 2019 ). IL-1β and IL-6 are the main pro-inflammatory cytokines secreted by the early inflammatory response, which can initiate the release of other cytokines ( Zhao et al, 2021 ). Zhang et al found that the concentration of TNFα, IL-6 and IL-1β in lung tissue was significantly increased following acute cold stress (−25°C) ( Zhang et al, 2015 ).…”

Nanozymes for Regenerative Medicine

“…OxgeMCC-r SAE with PVP outer Imaging and photodynamic therapy for cancer [44] Good stability and excellent biosafety NiCo 2 O 4 @PVP Anti-inflammatory therapy [45] Biodegradable and biocompatible properties MoSe 2 -PVP Acute pancreatitis [46] Biocompatibility and stability Ir NPs-PVP Acute kidney injury [47] Dextran Biocompatibility and biofilm targeting specificity Dextran-coated iron oxide Tooth decay and other biofilm-associated diseases. [48] Biocompatibility, deformation of biofilm, and wound healing Dextran-coated copper peroxide nanoaggregates (DCPNAs)…”

“…[44] In addition, benefiting from the favorable stability of the PVP in harsh environments such as gastrointestinal tract, Zhao et al successfully designed NiCo 2 O 4 @PVP nanozyme with multiple enzyme-like activities that was administered through oral delivery for anti-inflammation therapy. [45] The results revealed that NiCo 2 O 4 @PVP was more stable than the NiCo 2 O 4 without protection of PVP after treating with acidic media (pH1.2) for 12 h, and no deconstruction phenomenon of NiCo 2 O 4 @PVP was observed when exposed to the digestive tract for 4 h. Apart from providing excellent stability for NiCo 2 O 4 @PVP nanozyme, PVP also greatly contributed to biosafety and biocompatibility of NiCo 2 O 4 @PVP with biological media in vivo, which was indicated by the changes in body weight and the histopathology analyses data.…”