Surface Acoustic Wave-Based Microfluidic System for Studying Shear Stress-Induced Structural Changes in Human Aortic Endothelial Cells

Abstract Biomechanical factors connected to shear stress influence many physiological and pathophysiological processes in vascular systems, such as the transport of macromolecules through the endothelial barrier, gene expression, calcification or inflammation. Since these processes can be involved in diseases like cardiac valve stenosis or aortic aneurysms, predicting possible blood flow alterations and their effects on the cellular structure of the aortic wall is a highly relevant aim in medical research. While theoretical models have been established to describe and predict flow characteristics, the development of more flexible and precise experimental methods to generate different flow patterns and quantify flow-induced changes in cellular structures remains a challenge. For this purpose, we present a chip-based flow setup that allows for the analysis of cultured human aortic endothelial cells (HAEC) under versatile and easily tunable flow conditions via generation of surface acoustic waves (SAW). To address the question if exposure of endothelial cells to acoustically induced streaming in our setup leads to short-term changes in cellular structure, we cultivate HAEC cells for 3 h and show that the morphology and actin cytoskeletal structure is altered depending on the intensity of the surface acoustic wave and the resulting applied shear stress. Future applications of our experimental setup could facilitate predictions of early changes in the structure of cells in the aortic wall that are induced by aortic dysfunctions and blood flow alterations.