DETERMINATION OF FLUID MECHANICAL EFFECTS CAUSED BY NEAR WALL BLOOD FLOW FIELD ON ENDOTHELIAL CELL DAMAGE: EFFECT OF RED BLOOD CELLS IN WORKING FLUID
Miria Suzuki1, Toshiyuki Hayase2, Suguru Miyauchi2, Kosuke Inoue2
1Tohoku University, Japan;
2Institute of Fluid Science, Tohoku University, Japan
Endothelial cells (ECs) that line the inner wall of blood vessels play vital roles in maintaining homeostasis of the circulatory system and damage to these cells is known to lead to vascular diseases including atherosclerosis. Former studies have focused on the effects of three types of mechanical forces that are applied to ECs in their local environment, which are shear stress due to blood flow, hydrostatic pressure due to blood pressure and cyclic stretch due to vessel deformation. This study, however, focused on forces that are applied to ECs due to interaction with the passage of red blood cells (RBCs) in the blood stream. To the best of our knowledge, EC flow load studies to date have used cell medium as the working fluid and have not looked at the effect of RBCs. The aim of this study therefore is to determine the effect of RBCs on the degree of EC damage under different flow conditions. ECs were cultured in a flow load chamber and flow load applied using cell medium with and without RBCs obtained from goat’s blood as the working fluid. Damage to ECs were measured indirectly by the degree of cell peeling from the substrate at each incrementally increasing flow rate and staining with fluorescent dyes. Shear stress applied to the ECs was evaluated by measurement of the pressure difference inside the chamber. The effect of aligning ECs in the direction of flow on their viability, which replicates the state of ECs in vivo, was also investigated. By comparing the results of these experiments, this study has determined the effect of near wall blood flow of RBCs on EC damage.