Effect of Substrate Composition and Compliance on Endothelial Expression of ICAM-1 and E-Selectin under Constant Shear Stress
Bayne, Kevan and Kelso, Bret
Harrington Department of Bioengineering, Arizona State University
Mentor: Caplan, Michael; Harrington Department of Bioengineering, Arizona State University
One of the central challenges to developing biocompatible vascular grafts is controlling the adhesion of leukocytes and immune responses leading to inflammation and scar tissue formation. Natural materials such as blood vessels, do not normally recruit inflammation and prior research suggests that substrate composition and compliance influence expression of leukocyte adhesion receptors ICAM-1 and E-Selectin, as well as other biologically relevant molecules such as nitric oxide. Thus, two factors thought to be important to maintaining endothelial cells in an anti-inflammatory state are the extracellular matrix (ECM) proteins and the mechanical compliance of the substrate to which they adhere. In this study we create poly(acrylamide) gels with differing compliance which are cross-linked to one or more ECM molecules to examine the effect of substrate composition and compliance on the expression of leukocyte adhesion receptors ICAM 1 and E Selectin by human umbilical vascular endothelial cell (HUVEC), using fluorescence activated cell sorting (FACS). Building upon past work done by Caplan Lab under non-flow conditions, this study utilizes an experimental setup that mimics physiological conditions of constant shear stress and temperature. Preliminary results have shown that there is a statistically significant effect of culturing HUVECs on substrates with various stiffness and modified with different ECM components.