Catalytic nanozymes for ulcerative colitis: harnessing immune-redox crosstalk for mucosal healing and disease remission

Ulcerative colitis (UC) is a chronic inflammatory bowel disease (IBD) characterized by disruption of the epithelial barrier, immune dysregulation, oxidative stress, and persistent mucosal inflammation. Although current therapies, including biologics and small-molecule agents, have improved disease management, many patients experience inadequate responses, adverse effects, and disease recurrence. Growing evidence indicates that immune dysfunction and redox imbalance form an interconnected pathogenic network that drives disease progression, highlighting the need for therapies that can simultaneously target both processes. Nanozymes, a class of nanomaterials with intrinsic enzyme-mimetic catalytic activity, have emerged as promising therapeutic platforms for catalytic medicine. Through superoxide dismutase (SOD), catalase (CAT), peroxidase, and glutathione peroxidase (GSH-Px)-like activities, nanozymes efficiently eliminate reactive oxygen species (ROS) and reactive nitrogen species (RNS), restore redox homeostasis, and protect intestinal barrier integrity. In addition to their antioxidant functions, specific nanozyme formulations have been shown to modulate macrophage polarization, attenuate inflammatory cytokine production, regulate innate and adaptive immune responses, and promote mucosal healing in preclinical UC models. Recent advances in catalytic optimization, stimuli-responsive systems, biomimetic engineering, and colon-targeted delivery have further enhanced their therapeutic potential. This review summarizes the role of immune–redox crosstalk in UC, discusses nanozyme classifications and mechanisms of action, highlights emerging engineering strategies, and evaluates current preclinical progress and translational challenges in this field. Nanozyme-based catalytic medicine represents a promising preclinical strategy that may contribute to durable remission and restore intestinal homeostasis in experimental models of UC. However, clinical translation requires further validation of long-term efficacy and safety.