Ju-Zhen Yi,Kunhua Lin,Hao Wu,Xuhong Mao,Li-Ming Zhang,Liqun Yang
A hydrogel comprising covalently modified carboxylated pullulan and concanavalin A (CPUL-ConA) was prepared with glucose-sensitivity in a simulated small intestinal fluid containing glucose. The acarbose-encapsulated CPUL-ConA (Acar/CPUL-ConA) hydrogel, with an acarbose encapsulation ratio of 0.63, was prepared by immersing the dried CPUL-ConA hydrogel in an acarbose/PBS (pH 7.2) solution. In the simulated gastric fluid, less than 20% acarbose was released from the Acar/CPUL-ConA hydrogel, which could be beneficial to protecting the stomach. In contrast, more than 80% acarbose was smartly controlled released from the Acar/CPUL-ConA hydrogel in the simulated small intestine fluid containing glucose. Scanning electron microscopy provided further evidence of the smart release of acarbose from the Acar/CPUL-ConA hydrogel in simulated gastrointestinal fluids, which is advantageous to inhibiting α-glucosidase activity and subsequently reducing the postprandial blood glucose levels, as well as helpful for reducing the gastrointestinal dysfunction of acarbose. Rheological analysis indicated that the Acar/CPUL-ConA hydrogel showed characteristics of chemical crosslinked hydrogels. There was no obvious shear thinning behavior, suggesting that the Acar/CPUL-ConA hydrogel could be stable under gastric and intestinal peristalsis. Therefore, the Acar/CPUL-ConA hydrogel is anticipated to improve the therapeutic efficacy of postprandial hyperglycemia and type 2 diabetes.
Ben Chen,Dingwei Li,Bingjie Tong,Lifen Wang,Haoran Lin,Helin Xu,Sunkuan Hu
Ulcerative colitis (UC) is a chronic bowel inflammatory disease affecting the colorectum. Epidermal growth factor (EGF) has been demonstrated to be effective to counteract UC. However, there exists the gastrointestinal challenges such as stomach acid, enzyme and bile salts for oral delivery of EGF. Herein, calcium alginate microsphere was prepared by the microfluidic technique to encapsulate EGF. The morphology of EGF-loaded microsphere (MS-EGF) was spherical and its average particle size was 80 ± 23 μm. The encapsulation efficiency of EGF was reaching to 93.8 % ± 1.6 %. In vitro release experiments showed that MS-EGF presented the good pH-sensitive properties, that was, it could effectively resist the gastric acid and small intestinal fluids, and undergone the rapid dissolution in the artificial colon fluid. In vitro cellular experiments demonstrated that the bioactivity of EGF was well preserved by microsphere. Moreover, in vivo murine colitis model showed that MS-EGF presented the obvious colitis alleviation. Furthermore, the colonic morphology of colitis mice was effectively recovered and the tight junction between the gut epithelium was obviously repaired. In conclusion, calcium alginate microsphere might be a promising vehicle of EGF for UC treatment.
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