MnNi@PVP\nNanoenzyme Based on Regulating Inflammation\nand Immune Homeostasis for the Therapy of Inflammatory Bowel Disease

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