Dual-targeted colon-based integrated micelle drug delivery system for treatment of ulcerative colitis

Emodin (EMO) is an active ingredient of Chinese traditional medicine with the potential to reportedly treat ulcerative colitis (UC). However, the solubility of EMO in water is poor coupled with low oral bioavailability, whilst existing conventional oral preparations of the drug lack targeting ability. Thus, this work sought to design and fabricate a mannose modified colon targeted micelle drug delivery system comprising quantum dots (QDs) and EMO to obtain Eu-CS-Man-Ps-P(HEMA-DMAM)/EMO-QDs, which exhibited stable physicochemical properties, smaller average sized droplets (226.22 ± 1.83 nm), better polydispersity (PDI = 0.060 ± 0.005), negative ζ-potential (-19.19 ± 0.89 mV) and high efficiency of encapsulation (95.14 ± 0.23%). We observed Eu-CS-Man-Ps-P(HEMA-DMAM)/EMO-QDs to be an effective approach for the improvement of EMO solubility in an aqueous medium with an increased oral bioavailability (3.23 times higher than native drug) of the drug. Besides, the micelle could increase the retention and release of EMO in colonic ulcers through multi-stage targeting, improve oral bioavailability, regulate the expression of inflammatory factors and repair damaged tissues, which helped us to achieve the design goal of integrated diagnosis and treatment of UC. Conclusively, the therapeutic effect of EMO was enhanced through an integrated micelle, which exhibited good prospects in improving solubility and oral biological availability.