Co-existing colloidal phases of human duodenal aspirates: Intraindividual fluctuations and interindividual variability in relation to molecular composition

Publication date: Available online 15 March 2019Source: Journal of Pharmaceutical and Biomedical AnalysisAuthor(s): Philipp A. Elvang, Mette Sloth Bohsen, Paul C. Stein, Annette Bauer-Brandl, Danny Riethorst, Joachim Brouwers, Patrick Augustijns, Martin BrandlAbstractWe investigated the ultrastructural pattern of colloidal phases in human duodenal fluids. Aspirates were collected from three volunteers in both fasted and fed nutritional states. Analysis methods comprised the combination of asymmetric flow field-flow fractionation (AF4) and multi-angle laser light scattering (MALLS). Furthermore, dynamic light scattering (DLS) and diffusion-ordered NMR spectroscopy (DOSY-NMR) were employed as alternative analytical approaches for comparison.By AF4/MALLS, up to four, and in some cases up to five distinct co-existing fractions could be differentiated in the sub-micron size-range, which, in accordance with a previous study (Elvang et al., 2018), may be assigned to three main types, namely small bile salt micelles, intermediate size mixed bile salt/phospholipid micelles and large phospholipid aggregates / vesicles. Although more or less the same colloidal phases were found to co-exist in all aspirates, their prevalence was found to vary, both over time and between the three individual human volunteers. Any uniform changes of patterns of colloidal phases over time, however, could not be identified. On the other hand, prevalence of specific colloidal phases was identified for aspirat...
Source: Journal of Pharmaceutical and Biomedical Analysis - Category: Drugs & Pharmacology Source Type: research