Ultra-small Prussian blue nanodots scavenge reactive oxidative species and balance M1/M2 macrophages to mitigate colitis inflammation

Inflammatory bowel disease (IBD) is characterized by an overproduction of reactive oxygen species (ROS) and an imbalance in macrophage activity, highlighting the need for innovative treatments that combine anti-inflammatory efficacy with strong clinical potential. We developed ultrasmall Prussian blue nanodots (UPBs) utilizing a novel solvation effect preparation method, achieving quantum dots with enhanced nanocatalytic activity and superior ROS scavenging capabilities, with an average size of 3.1 nm. These UPBs exhibited negligible cytotoxicity at concentrations below 20 μg mL^-1 and showed remarkable efficacy in scavenging ROS within lipopolysaccharide-stimulated macrophages. In a dextran sulfate sodium (DSS)-induced colitis mouse model, UPBs effectively modulated macrophage polarization from pro-inflammatory M1 to anti-inflammatory M2, enhancing therapeutic outcomes by regulating inflammatory cytokine secretion and restoring intestinal epithelium integrity. This study highlights the potential of UPBs to significantly improve IBD treatment by combining ROS scavenging with intestinal microenvironment modulation, suggesting promising avenues for future clinical applications.