title: A novel perfusion system for the endothelialisation of PTFE grafts under defined flow.
abstract: OBJECTIVE
  to develop a perfusion system for culturing human endothelial cells on small-diameter PTFE grafts under defined pulsatile shear stress.
  
  
  METHODS
  to benefit from a stronger adhesion of endothelial cells to the substrate, we developed a perfusion system which enables culture of endothelial cells on PTFE grafts to confluence under a wide range of shear stress. We also developed an in situ staining method for the determination of the endothelialisation stage by upper light microscopy.
  
  
  RESULTS
  the application of pulsatile flow with high shear stress (6.6 dyn/cm2, 5 min) to a graft endothelialised under perfusion did not lead to a disruption of the confluent cell layer. In contrast, a shear stress of 3 dyn/cm2 applied for 5 min was sufficient to wash more than 50% of endothelial cells off the PTFE graft when cultured to confluence under static conditions.
  
  
  CONCLUSIONS
  this technique induces a stronger cell adherence of endothelial cells to a PTFE graft in comparison with grafts endothelialised under static conditions. Endothelialised vascular grafts can be pre-conditioned to defined shear stress values.
authors.affiliation: Department of Rheumatology, Charité Medical School Research Group, Berlin, Germany.
authors.forename: T R
authors.initials: TR
authors.lastname: Dunkern
authors.forename: M
authors.initials: M
authors.lastname: Paulitschke
authors.forename: R
authors.initials: R
authors.lastname: Meyer
authors.forename: R
authors.initials: R
authors.lastname: Büttemeyer
authors.forename: R
authors.initials: R
authors.lastname: Hetzer
authors.forename: G
authors.initials: G
authors.lastname: Burmester
authors.forename: M
authors.initials: M
authors.lastname: Sittinger
mesh_terms: D001807:Blood Vessel Prosthesis; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology*; D004867:Equipment Design; D005337:Fibrin; D006801:Humans; D066298:In Vitro Techniques; D011138:Polytetrafluoroethylene; D011673:Pulsatile Flow; D013314:Stress, Mechanical; D013927:Thrombosis / Q000517:prevention & control; D014471:Umbilical Veins / Q000166:cytology
chemical_list: D005337:Fibrin; D011138:Polytetrafluoroethylene