Daeyoung Kim

pH-sensitive mesalazine carrier for colon-targeted drug delivery: A two-fold composition of mesalazine with a clay and alginate

AbstractThe release of mesalazine, an anti-inflammatory drug for Crohn’s disease, should be deferred while delivering along the gastrointestinal tract to maximize drug absorption in the colon. To that end, we intercalated mesalazine into a clay mineral, montmorillonite (MMT), and we encapsulated the resulting composite inside a pHsensitive polymer, an alginate hydrogel bead. Once intercalated between the microscopic MMT layers, the mesalazine is prevented from dissolution during encapsulation into the alginate beads. As the resulting mesalazine-clay-alginate (MCA) bead is covered with a protective alginate layer, the mesalazine does not dissolve in acidic gastric conditions. In in vitro release tests, the MCA beads exhibited less than 5% mesalazine release in gastric solution, while ~20% was released over 7 h in the intestinal condition. Our results demonstrate that the MCA bead is a highly effective, biocompatible means of mesalazine delivery to the colon.n

Effects of bentonite Bgp35b-p on the gut microbiota of mice fed a high-fat diet: Effects of bentonite on the gut microbiome

BACKGROUNDnBentonite is a natural clay mineral with health-promoting effects due to its high adsorption abilities with high cation-exchange capacity. Previously, we found an anti-obesity effect for Bgp35b-p bentonite produced in South Korea, where its high adsorbent ability of dietary lipids possibly partially removed the lipidic environment in the gut (unpublished). It is hypothesized that Bgp35b-p affects the intestinal microbial community, and thus the microbial changes were investigated via next-generation sequencing targeting the bacterial 16S rRNA gene and bioinformatics using QIIME (Quantitative Insights Into Microbial Ecology) were performed on feces of C57BL/6 male mice fed a high-fat diet (HFD) with the Bgp35b-p.nnnRESULTSnThe HFD caused microbial dysbiosis, characterized by a decrease in the relative abundance of Bacteroidetes and an increase in abundance of Firmicutes and Proteobacteria. It was found that HFDu2009+u2009Bgp35b-p led to significant changes in the microbial compositions of family-level bacteria known as short-chain fatty-acid-producing bacteria. The relative abundance of Ruminococcaceae was significantly increased, and the abundances of Clostridiaceae and Lachnospiraceae were decreased by HFDu2009+u2009Bgp35b-p, shifting close to that in mice fed a normal diet.nnnCONCLUSIONnBgp35b-p induced compositional changes in intestinal microbiota, which can be considered as a prebiotic effect, thus suggesting that bentonite may be a potential prebiotic functional supplement.