Fabrication of Microcrystalline Cellulose/ZnO Quantum Dots with Enhanced Zinc Bioavailability for Alleviating DSS-Induced Ulcerative Colitis in Mice

Ulcerative colitis (UC), as a common inflammatory bowel disease (IBD), poses a significant threat to human intestinal health and has become a global public health issue. As an essential trace element, zinc plays a crucial role in maintaining intestinal homeostasis and mitigating UC progression. However, conventional zinc oxide (ZnO) suffers from low bioavailability; excessive unabsorbed zinc leads to environmental pollution, and long-term overuse can induce bacterial resistance. To address these critical drawbacks, a microcrystalline cellulose-supported ZnO quantum dots (MCC@ZnO QDs) composite was synthesized via a sol-gel method, where ZnO quantum dots were immobilized onto microcrystalline cellulose (MCC) matrices. The antibacterial activity and protective efficacy of the composite against dextran sulfate sodium (DSS)-induced colitis were systematically evaluated. Despite a ZnO loading of approximately 78.77 wt %, the MCC@ZnO QDs composite exhibited therapeutic effects comparable to those of pure ZnO QDs, including alleviating weight loss, restoring colon length, repairing intestinal barrier integrity, regulating inflammatory cytokine expression, enhancing antioxidant capacity, and remodeling the gut microbiota. This composite enhances zinc bioavailability, thereby achieving dose reduction with improved efficacy and providing a green, efficient strategy for the intervention of UC.