The accumulation and sustained release of drugs in the colonic inflammatory region are the favorable strategy for treating ulcerative colitis (UC). In this study, we developed a synergistic anti-inflammatory drug (quercetin/EGCG)-loaded micelle using hydrolytic quinoa protein (HQP) and cationic lotus root starch (CLRS) by a layer-by-layer assembly method. The encapsulation efficiency of quercetin and EGCG in the Que-HQP-EGCG-CLRS micelles reached 91.5 and 89.4%, respectively. This composite micelle exhibited a core-shell structure, where Que-HQP-EGCG was the core and CLRS was the coating shell. Moreover, the in vitro experiments indicated that these micelles can make Que/EGCG pass through gastric environments stably and delay their release in the intestine. Animal experiments further confirmed that the Que-HQP-EGCG-CLRS micelles can efficiently accumulate in the colonic inflammatory region and enable sustained release of drugs (more than 24 h), thus notably alleviating the symptoms of UC. These results suggested that Que-HQP-EGCG-CLRS micelles have good gastric stability, colonic inflammatory-accumulated effect, and sustained drug release ability, which are a promising co-delivery system for UC treatment.
Keywords: cationic lotus root starch; co-delivery micelles; hydrolytic quinoa protein; sustained drug release; ulcerative colitis.