Curcumin Nanocrystal/pH-Responsive Polyelectrolyte Multilayer Core–Shell Nanoparticles for Inflammation-Targeted Alleviation of Ulcerative Colitis

In this study, we developed oral core–shell nanoparticles composed of curcumin nanocrystals in the core and chitosan/alginate multilayers in the shell for inflammation-targeted alleviation of ulcerative colitis (UC). The release rate of curcumin from the core–shell nanoparticles was low at a pH mimicking the stomach and small intestine, whereas it was higher at a pH mimicking the colon. Further, biodistribution studies in the gastrointestinal tract of mice showed that distribution of nanoparticles was significantly higher in the colon than that in the stomach and small intestine. Quantitative analysis of drugs in colonic tissues and confocal imaging of colons revealed preferential accumulation of nanoparticles in inflamed tissues than that in healthy tissues. In vivo anti-inflammatory studies revealed that nanoparticles exhibit enhanced efficacy in alleviating inflammation-related symptoms in a mouse colitis model. The results suggest that the core–shell nanoparticles presented here can be exploited as efficient colon-targeted drug delivery systems for UC therapy.