Colon-targeted oral nanoparticles based on ROS-scavenging hydroxyethyl starch-curcumin conjugates for efficient inflammatory bowel disease therapy

Co-delivery of anti-inflammatory drugs and reactive oxygen species (ROS) scavengers by stimuli-responsive oral nanoparticles is deemed to be a favorable strategy for inflammatory bowel disease (IBD) therapy. In this study, using micelles formed by CUR conjugated hydroxyethyl starch (HES) as vehicles, dexamethasone (DEX)-loaded HES-CUR nanoparticles (DHC NPs) with desirable size, negative surface charge, good stability in the harsh gastric environment, and excellent ROS scavenging activity are developed as a colon-targeted oral formulation for treating IBD. Due to the degradation of HES in response to alpha-amylase overexpressed in the inflamed colon, the DHC NPs release drugs in an alpha-amylase-responsive manner. Meanwhile, the DHC NPs can be effectively internalized by macrophages and show excellent cytocompatibility with macrophages since they are composed of food-derived compounds. Importantly, in vivo studies reveal that the DHC NPs are capable of targeting the inflamed colon induced by dextran sulfate sodium (DSS), and the targeted and combination therapy enhances the efficacy of free DEX and significantly relieves the impairment caused by DSS-induced ulcerative colitis. Incorporating the merits of targeted drug delivery and combined therapy with an anti-inflammatory drug and ROS scavenger, the DHC NPs are promising for developing novel oral formulations for IBD therapy.