title: Comparing the endothelialisation of extracellular matrix bioscaffolds with coated synthetic vascular graft materials.
abstract: BACKGROUND
  Existing synthetic vascular grafts have unacceptably high failure rates when replacing below knee arteries. In vitro endothelialisation is a technique, which has been shown to enhance the patency rates of below knee vascular grafts. Synthetic materials are however poor cellular substrates and must be combined with coatings to promote cellular growth and attachment. The most common coating clinically is fibrin-coated ePTFE. The aim of our study was to compare the endothelialisation of fibrin-coated ePTFE with novel extracellular matrix (ECM) biomaterials that we hypothesise will provide a superior substrate for cell growth.
  
  
  METHODS
  Human endothelial cells were cultured on ECM scaffolds and fibrin-coated ePTFE. Uncoated Dacron and ePTFE acted as controls. The cells were examined for viability, phenotype, adhesion and proliferation. Cell morphology was accessed using scanning electron microscopy.
  
  
  RESULTS
  Cells remained viable and produced von Willebrand factor on all substrates tested. ECM scaffolds and fibrin-modified ePTFE achieved statistically higher attachment efficiency when compared to both uncoated synthetic graft materials (p ≤ 0.001). At 90 min 80 ± 3.6% of cells had attached to the ECM scaffold compared to Dacron (30 ± 4.5%, n = 3) and ePTFE (33 ± 2.5%, n = 3). There was no difference in adhesion rates between ECM scaffolds and fibrin-coated ePTFE (p = 1.00). Endothelial cells proliferated fastest on ECM scaffolds when compared to all other materials tested (p < 0.001) and reached confluency on day seven.
  
  
  CONCLUSIONS
  ECM bioscaffolds offer an improved substrate for promoting rapid endothelialisation compared to fibrin-coated ePTFE by combining firm cellular anchorage and superior cell expansion.
authors.affiliation: Department of Vascular Surgery, University Hospital Limerick, Limerick, Ireland. Electronic address: drdanielcoakley@gmail.com.
authors.forename: D N
authors.initials: DN
authors.lastname: Coakley
authors.affiliation: Department of Vascular Surgery, University Hospital Limerick, Limerick, Ireland.
authors.forename: F M
authors.initials: FM
authors.lastname: Shaikh
authors.affiliation: The Statistical Consultancy Unit, School of Mathematical Sciences, University College Cork, Cork, Ireland.
authors.forename: K
authors.initials: K
authors.lastname: O'Sullivan
authors.affiliation: Department of Vascular Surgery, University Hospital Limerick, Limerick, Ireland.
authors.forename: E G
authors.initials: EG
authors.lastname: Kavanagh
authors.affiliation: Department of Vascular Surgery, University Hospital Limerick, Limerick, Ireland.
authors.forename: P A
authors.initials: PA
authors.lastname: Grace
authors.affiliation: Department of Vascular Surgery, University Hospital Limerick, Limerick, Ireland.
authors.forename: S R
authors.initials: SR
authors.lastname: Walsh
authors.affiliation: Department of Mechanical and Aeronautical Engineering, Materials and Surface Science Institute, University of Limerick, Centre for Applied Biomedical Engineering Research, Limerick, Ireland.
authors.forename: T M
authors.initials: TM
authors.lastname: McGloughlin
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000379:methods*; D002448:Cell Adhesion; D049109:Cell Proliferation; D002478:Cells, Cultured; D020099:Coated Materials, Biocompatible; D042783:Endothelial Cells / Q000166:cytology; D004730:Endothelium, Vascular / Q000166:cytology*; D005109:Extracellular Matrix / Q000502:physiology*; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D008855:Microscopy, Electron, Scanning; D011138:Polytetrafluoroethylene; D013552:Swine; D054457:Tissue Scaffolds; D014654:Vascular Patency
chemical_list: D020099:Coated Materials, Biocompatible; D011138:Polytetrafluoroethylene
keywords: Biomaterials; Endothelialisation; Extracellular matrix (ECM); Tissue engineering; Vascular grafts