Endothelial cells seeded on elastin–heparin matrices express normal EC markers and resist detachment on exposure to shear stress: a histological study

Abstract

Endothelialization of vascular graft surfaces has been suggested as a method to prevent thrombosis-related failure. The purpose of this study was to examine the ability of endothelial cells (ECs) seeded on novel elastin–heparin scaffolds to resist detachment on exposure to physiological levels of shear stress and to evaluate whether these cells maintain a quiescent profile on these scaffolds by investigating the expression of thrombomodulin (TM) and adhesive molecules platelet endothelial cell adhesion molecule-1 (PECAM-1) and intercellular adhesion molecule-1 (ICAM-1). To evaluate the functional response of the cultured endothelium on injury, the cellular response (ICAM-1 expression) to physiological stimulatory factor tumor-necrosis factor (TNF)-alpha was analyzed. The ECs formed a confluent monolayer expressing PECAM-1 and TM very similar to native aortic ECs. ICAM-1 expression was slightly higher than that observed on tissue culture polystyrene (TCPS), but was similar to that seen on several other polymers. Furthermore, the cells responded to stimulation by TNF-alpha (expression of ICAM was elevated by ∼30%). These results indicate that the ECs seeded on elastin–heparin scaffolds express normal EC molecules and may provide an efficient anti-thrombogenic surface for these tissue-engineered vascular grafts.