Pulsatile soft lubrication: How fibrous boundaries facilitate blood flow

Abstract

The endothelial glycocalyx layer (EGL), with its inherent fibrous architecture enveloping the interior surfaces of blood vessels, paradoxically increases resistance to blood flow. This phenomenon poses a significant question: how do physiological systems overcome the enhanced resistance imparted by the EGL? Addressing this knowledge gap, this study proposes a new theoretical framework to analyze the dynamic behavior of the EGL in the setting of pulsatile blood flow. Central to our investigation is the novel concept of pulsatile soft lubrication, a potential mechanism for mitigating flow resistance. Utilizing a theoretical model that mimics fluid dynamics across parallel fibrous boundaries, we explore the intricate interplay between fluid motion and EGL fibers under pulsatile pressure gradients. The results indicate that the EGL's natural elasticity engenders a dynamic interface that notably lessens flow resistance, thereby enhancing flow rates. Beyond advancing our understanding of the EGL's critical function in hemodynamics, this research also highlights its broader implications, suggesting relevance in engineering and design principles. Insights into fluid dynamics and surface interactions garnered from this study could inform innovative strategies for reducing friction and optimizing flow across a variety of systems.