Ultra-Tough Self-Healing Hydrogel via Hierarchical Energy Associative Dissipation.

Owing to high water content and homogeneous texture, conventional hydrogels hardly reach satisfactory mechanical performance. Tensile-resistant groups and structural heterogeneity are employed to fabricate tough hydrogels. However, those techniques significantly increase the complexity and cost of material synthesis, and have only limited applicability. Here, it is shown that ultra-tough hydrogels can be obtained via a unique hierarchical architecture composed of chemically coupled self-assembly units. The associative energy dissipation among them may be rationally engineered to yield libraries of tough gels with self-healing capability. Tunable tensile strength, fracture strain, and toughness of up to 19.6 MPa, 20 000%, and 135.7 MJ cm⁻3 are achieved, all of which exceed the best known records. The results demonstrate a universal strategy to prepare desired ultra-tough hydrogels in predictable and controllable manners.

[Effects of 6-Shogaol on Notch signaling pathway in colonic epithelial cells of ulcerative colitis mice].

OBJECTIVE: To observe the regulatory effect of 6-Shogaol on Notch signal pathway in colonic epithelial cells of mice with ulcerative colitis. METHODS: Forty Kunming mice were randomly divided into normal group (n=10) and model group (n=30). The model of ulcerative colitis was induced by free drinking of 2% dextran sulfate sodium salt(DSS). After 15 days, the mice were divided into model group, 6-gingerenol group and positive control group with 10 mice in each group. Normal group and model group were treated with normal saline, 6-gingerenol group was treated with 6-Shogaol 100 mg/(kg·d), positive control group was treated with sulfasalazine 100 mg/(kg·d), for 20 days. The histopathological changes of colon were observed, and the expressions of Hes-1 and Math-1protein in colonic epithelial cells were detected by immunofluorescence double labeling method. The expressions of Notch-1, Hes-1 and Math-1 mRNA in colonic epithelial tissue were detected by RT-PCR. The expressions of Notch-1, Hes-1 and Math-1 protein in colonic epithelial tissue was detected by Western blot. RESULTS: Compared with the normal group, the expression of Notch-1 and Hes-1 protein and the relative expression of mRNA in colonic epithelium of model group were significantly increased (P＜0.01), while the relative expressions of Math-1 mRNA and protein were decreased significantly (P＜0.01). Compared with the model group, the expressions of Notch-1 and Hes-1 protein and the relative expression of mRNA in colonic epithelium of 6-Shogaol group and sulfasalazine group were decreased significantly(P＜0.01), while the relative expressions of Math-1 mRNA and protein were increased significantly(P＜0.01). CONCLUSION: 6-Shogaol can inhibit the over activation of Notch pathway and regulate the balance of differentiation between colonic epithelialabsorptive cell line and secretory cell line and repair damaged mucosal tissue.