Search

Crohn's disease (CD) is associated with chronic inflammation in regions throughout the gastrointestinal (GI) tract but is most likely to develop at the end of the small intestine and the first part of the colon. A single massive resection or multiple repeated resections in CD leads to short bowel syndrome (SBS). Therefore, a novel treatment to cure SBS is needed. Poly (vinyl pyrrolidone-methyl methacrylate) hydrogel is chosen as a self-inflating expander device to address the issue of inadequate functional intestinal length in SBS. The hydrogel employs mechanotransduction, wherein mechanical force elongates the intestine and activates cellular mechanisms regulating growth. In this study, the VP/MMA hydrogel was designed by varying the composition ratio of each monomer and size. The ratios of VP to MMA were 95:5wt%, 90:10wt%, and 85:15wt%. The shape of hydrogel was cylindrical with the sizes of 12mmD & 3mmL (A), 6mmD & 3mmL (B), 6mmD & 6mmL (C), 6mmD & 9mmL (D), 3mmD & 3mmL (E). These variables influenced the pore size structure, swelling capacity, swelling force, and mechanical property. Finally, the hydrogel with a composition ratio of 85:15 wt% VP/MMA (VP85) was chosen for ex vivo and in vivo studies. The reason is due to the pressure generated during swelling (77.9 kPa) close to the required stress value to stretch the small intestine (78.9 kPa). Due to the small size of the rat intestine, the 2mmD & 2mmL hydrogel was chosen. A stretched segment of the intestine was found to lengthen 2.5-folds from the original length on days 1 and 7. Histological intestine sample after being stretched using hydrogel showed a significantly greater muscularis thickness, crypt depth and villous height.