MnNi@PVP Nanoenzyme Based on Regulating Inflammation and Immune Homeostasis for the Therapy of Inflammatory Bowel Disease

Nanozymes exhibiting remarkable antioxidant capabilities represent an effective therapeutic approach for ulcerative colitis (UC). This study synthesized the MnNi@PVP nanoenzyme through high-temperature pyrolysis and the NaCl template method, which exhibited multienzyme activity comprising glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT). This study investigated the therapeutic effect of MnNi@PVP on colitis caused by sodium dextran sulfate (DSS). The findings indicated that MnNi@PVP notably decreased the disease activity index (DAI) score, which encompasses weight loss, colon shortening, and histopathological changes. MnNi@PVP showed effectiveness in addressing oxidative damage and suppressing the levels of proinflammatory markers, such as tumor necrosis factor (TNF-α), inducible nitric oxide synthase (iNOS), and interleukin (IL)-6, by inactivating the TLR4 pathway and macrophages. In addition, MnNi@PVP demonstrated the ability to repair tight junction proteins (occludin and ZO-1) and restore the intestinal barrier. The transcriptome sequencing demonstrated that MnNi@PVP could regulate inflammatory factor expression pathways and immune processes. Additionally, negatively charged MnNi@PVP can selectively bind to inflamed colonic tissues through electrostatic interactions, endowing it with targeted reparative capabilities at the location of intestinal inflammation. The MnNi@PVP, which possesses the reactive oxygen and nitrogen species (RONS) clearance capability examined in this section, is expected to provide the basis for the targeted repair of intestinal function.