Optimizing a Three Layered Electrospun Matrix to Mimic Native Arterial Architecture: Cellular and Mechanical Analysis

Abstract

The architecture of the vascular wall is highly intricate and requires unique biomechanical properties in order to function properly. Native artery is composed of a mix of collagen, elastin, endothelial cells (ECs), smooth muscle cells (SMC), fibroblasts, and proteoglycans arranged into three distinct layers: the intima, media, and adventitia. Throughout artery, collagen and elastin play an important role, providing a mechanical backbone, preventing vessel rupture, and promoting recovery while undergoing pulsatile deformations [1]. The low-strain mechanical response of artery to blood flow is dominated by the elastic behavior of elastin which prevents pulsatile energy from being dissipated as heat [2]. Previous work has shown the ability to fabricate multi-layered electrospun scaffolds composed of polycaprolactone (PCL), elastin (ELAS), and collagen (COL), and their associated mechanical advantages. PCL was chosen, in this case, to provide mechanical integrity and elasticity, while elastin and collagen would provide further elasticity and bioactivity [3,4]. However, when the grafts were implanted in the descending aorta of a rat, cellular results were not as desirable as predicted. Therefore, further graft optimization was required. The hypothesis of this study was that blended polymers and biopolymers would be conducive for cellular attachment through specific integrin binding sites. To test this hypothesis, human umbilical artery smooth muscle cells (hUASMC) were seeded on electrospun PCL, COL, and ELAS blends for evaluation in a cell adhesion inhibition experiment.