Abstract 250: Surface Microscale Topograhical Features Promotes Endothelial Cell Proliferation and Migration on a Nanocomposite Vascular Graft Material

Abstract

Objectives Micro and nanoscale surface topographical features have been shown to have an influence on cellular behaviour. Endothelisation of small diameter vascular grafts has long been thought to have beneficial and protective effects as well as ensuring patency of the graft. Our objective is to explore the potential of using surface topographical features on a biocompatible nanocomposite polymeric material to produce a ‘self-endothelising’ vascular graft. Methods Photolithography was used to fabricate microscale topographical grooves onto a mask. These features were then heat-casted onto a nanocomposite polymeric material made of polyhedral oligomeric silsesquioxane (POSS) and poly (carbonate urea) urethane (PCU). Fidelity of the microscale grooves were confirmed using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Human umbilical vein endothelial cells (HUVECs) were seeded onto POSS-PCU sheets with different microscale grooves and cellular behaviour was monitored daily. Cell proliferation and metabolic activity was measured using a colorimetric assay. Adhesion of the cells were confirmed using fluorescence microscopy. Results Our results show that grooves can be reproduced with high fidelity using masks produced by photolithography onto POSS-PCU nanocomposite polymer. Ridges of width 12.5 μm with channels widths of 25μm and subsequent depths of 300 - 700 nm were measured and confirmed using SEM and AFM These ordered grooves enhance cell spreading and adhesion compared with flat polymer surfaces. Furthermore, cell proliferation is further improved on these microscale features compared to featureless surfaces. Conclusion Microscale grooves on the surface of a nanocomposite polymeric material promotes increased endothelial cell adhesion, migration and proliferation. These ordered topographical features could be used to produce a new generation of vascular grafts with ‘self-endothelising’ potential.