Multiscale modeling of the glycocalyx layer : their impact on hemodynamics

• Κύριος συγγραφέας: Μητσούλας, Βλάσιος
• Άλλοι συγγραφείς: Mitsoulas, Vlasios
• Γλώσσα: English
• Έκδοση: 2020
• Θέματα: Glycocalyx; Fibers; Permeability; Αλληλεπίδραση στερεού-ρευστού; Γλυκοκάλυξ; Βιολογικές ίνες; Διαπερατότητα

The response of the fibrous layer covering the luminal surface of the vascular endothelium, the so-called endothelial glycocalyx layer (EGL), in variations of the hemodynamic environment is of vital importance for the regulation of the blood vessel permeability and the balance of the blood components, and in general, the homeostasis of an organ or an organism. This implies that we should quantify fundamental properties such as its apparent permeability, in addition to dynamic quantities like drag and torque on EG nanofibers, which are indicators of the glycocalyx mechanical integrity, and provide their dependence on the individual geometric features and mechanical properties of a single fiber. Because of the O(100 nm) length of the fibers and the lack of relevant technology, such an approach would be difficult to be pursued experimentally. Here, we propose an in-silico rheometric emulation based on start-up and pulsating shear experiments in a representative three-dimensional volume of the fibrous glycocalyx layer that accounts for the interaction of the blood plasma and the deformable glycoproteins. We present quantitative predictions for the drag and torque on each nanofiber for blood flow under physiological conditions, and we show that the apparent permeability is substantially affected by the elasticity of fibers and the fiber-to-fiber distance. Particularly, we propose specific analytical expressions for the apparent EGL permeability and conclude that it is a monotonic function of the fiber-to-fiber distance and a rational function of the fibers’ elasticity.