title: Vascular prostheses: performance related to cell-shear responses.
abstract: BACKGROUND
  This work concerned the endothelialization of vascular prostheses and subsequent improvement of functionality with respect to tissue engineering. The aim of the study was to investigate the initial, pre-shear stress cellular behavior with respect to three vascular biomaterials to explain subsequent cellular responses to physiological shear stresses.
  
  
  METHODS
  Expanded polytetrafluoroethylene (ePTFE), polyethyleneterephthalate (polyester; Dacron; PET), and electrostatically spun polyurethane (PU) (all pre-impregnated with collagen I/III) were cell-seeded with L929 immortalized murine fibroblasts or human umbilical vein endothelial cells (HUVECs). Cytoskeletal involvement, cell height profiles, and immunohistochemistry were examined after 7 d static culture.
  
  
  RESULTS
  All three vascular biomaterials demonstrated different structures. Cell behavior varied both between the materials and the two cell types: cytoskeletal involvement was greater for the HUVECs and the more fibrous surfaces; height profiles were greater for the L929 and PET, and lowest on PU. Immunohistochemistry of HUVEC samples also showed differences: PU revealed the greatest expression of intercellular adhesion molecule-1 and E-selectin (PET and ePTFE the lowest, respectively); ePTFE produced the greatest for vascular cell adhesion molecule-1 (PET the lowest).
  
  
  CONCLUSIONS
  Material substrate influenced the cellular response. Cells demonstrating firm adhesion increased their cytoskeletal processes and expression of cell-substratum and inter-cellular adhesion markers, which may explain their ability to adapt more readily to shear stress. The fibrous PU structure appeared to be most suited to further shear stress exposure. This study demonstrated the potential of the underlying vascular material to affect the long-term cellular functionality of the prosthesis.
authors.affiliation: UKCTE, Division of Clinical Engineering, Duncan Building, University of Liverpool, Liverpool, United Kingdom. k.d.andrews@liv.ac.uk
authors.forename: Kirstie D
authors.initials: KD
authors.lastname: Andrews
authors.forename: Patrick
authors.initials: P
authors.lastname: Feugier
authors.forename: Richard A
authors.initials: RA
authors.lastname: Black
authors.forename: John A
authors.initials: JA
authors.lastname: Hunt
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D001807:Blood Vessel Prosthesis; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000502:physiology*; D004730:Endothelium, Vascular / Q000502:physiology; D005347:Fibroblasts / Q000502:physiology*; D006801:Humans; D008422:Materials Testing; D051379:Mice; D011093:Polyethylene Terephthalates; D011138:Polytetrafluoroethylene; D011140:Polyurethanes; D011474:Prosthesis Design; D012038:Regeneration; D033081:Shear Strength; D023822:Tissue Engineering; D014471:Umbilical Veins
chemical_list: D001672:Biocompatible Materials; D011093:Polyethylene Terephthalates; D011140:Polyurethanes; D011138:Polytetrafluoroethylene