title: Magnetic microcapsules as novel biomonitors of cross-linking agents and diet-dependent reactive oxygen species in the human gastrointestinal tract.
abstract: Six healthy, scientifically informed human volunteers were given 14C-labeled polyethyleneimine (PEI) microcapsules by mouth. Fecal 14C recovery was inversely related to mean gut transit time (r = -0.66), and the extent of cross-linking between the membrane and core PEI was inversely related to total fecal output (r = -0.81). Cross-linking of PEI microcapsules may be a biomonitor of endogenous cross-linking agents within the human gastrointestinal tract. Extensive loss of [14C]CH3 label occurred from the microcapsules during human transit and in in vitro fermentations with human fecal flora. A mechanism whereby reactive oxygen species could arise in the iron-rich core of these microcapsules, leading to loss of [14C]CH3 label, is proposed.
authors.affiliation: MRC Dunn Clinical Nutrition Centre, Cambridge, UK.
authors.forename: S A
authors.initials: SA
authors.lastname: Bingham
authors.forename: A B
authors.initials: AB
authors.lastname: Shah
authors.forename: A
authors.initials: A
authors.lastname: Ellul
authors.forename: J H
authors.initials: JH
authors.lastname: Cummings
authors.forename: I K
authors.initials: IK
authors.lastname: O'Neill
mesh_terms: D000328:Adult; D002214:Capsules; D003432:Cross-Linking Reagents / Q000378:metabolism*; D004249:DNA Damage; D004032:Diet; D004064:Digestive System / Q000378:metabolism*; D004784:Environmental Monitoring / Q000379:methods*; D005260:Female; D006801:Humans; D008280:Magnetics; D008297:Male; D008875:Middle Aged; D011094:Polyethyleneimine; D017382:Reactive Oxygen Species / Q000378:metabolism*
chemical_list: D002214:Capsules; D003432:Cross-Linking Reagents; D017382:Reactive Oxygen Species; D011094:Polyethyleneimine