%0 Generic
%A Amadei, Federico
%D 2019
%F heidok:26893
%K GIXPCS, Interfacial Gelation, Dynamic Adhesion, Probiotics (LGG), Interfacial Potential, RICM
%R 10.11588/heidok.00026893
%T The physics of complex, biological interfaces and its role in the homeostatic regulation of the human gastrointestinal tract.
%U https://archiv.ub.uni-heidelberg.de/volltextserver/26893/
%X The primary aim of this thesis was to quantitatively investigate the physics of complex, biological interfaces in intestines by the combination of well-defined model systems and unique experimental techniques. In Chapter 4, the formation of food colloids, via crosslinking negatively charged polyalginate by Ca2+ ions, was modeled at the o/w interface. The temporal evolution of the polymer chain dynamics during the gelation was detected by means of grazing incidence X-ray photon correlation spectroscopy (GI-XPCS) at the liquid/liquid interface for the first time. In Chapter 5, the significance of interfacial interactions between various lipids and mucin proteins was quantitatively compared by the combination of an in vitro mucus model and label-free microinterferometry. Remarkably, the enrichment of phosphatidylcholine at the mucus/lumen interface cannot be explained by the classical electrostatics. In Chapter 6, the mechanism of the adhesion of probiotic bacteria to the mucins was investigated under hydrodynamic shear mimicking the in vivo intestinal environment. The dynamic adhesion of probiotic bacteria is enhanced at the shear stress of 0.3 Pa, which showed a good agreement with in vivo conditions. The obtained results demonstrated that the combination of in vitro models together with unique experimental techniques yields the structures, dynamics, and interactions occurring at complex, biological interfaces.