Oral Drug Delivery Systems for Ulcerative Colitis Therapy: A Comparative Study with Microparticles and Nanoparticles

Background: Oral administrations of microparticles (MPs) and nanoparticles (NPs) have been widely employed as therapeutic approaches for the treatment of ulcerative colitis (UC). However, no previous study has comparatively investigated the therapeutic efficacies of MPs and NPs. Methods: In this study, curcumin (CUR)-loaded MPs (CUR-MPs) and CUR-loaded NPs (CUR-NPs) were prepared using a single water-in-oil emulsion solvent evaporation technique. Their therapeutic outcomes against UC were further comparatively studied. Results: The resultant spherical MPs and NPs exhibited slightly negative zeta-potential with average particle diameters of approximately 1.7 μm and 270 nm, respectively. It was found that NPs exhibited a much higher CUR release rate than MPs within the same period of investigation. In vivo experiments demonstrated that oral administration of CUR-MPs and CUR-NPs reduced the symptoms of inflammation in a UC mouse model induced by dextran sulfate sodium. Importantly, CUR-NPs showed much better therapeutic outcomes in alleviating UC compared with CUR-MPs. Conclusion: NPs can improve the anti-inflammatory activity of CUR by enhancing the drug release and cellular uptake efficiency, in comparison with MPs. Thus, they could be exploited as a promising oral drug delivery system for effective UC treatment.