RESISTANCE OF FRESHLY ADHERENT ENDOTHELIAL-CELLS TO DETACHMENT BY SHEAR-STRESS IS MATRIX AND TIME-DEPENDENT

PURPOSE: The placement of endothelial cells on the surfaces of arterie s immediately after vascular interventions has the potential to limit restenosis by inhibiting intimal thickening and by stimulating arteria l enlargement. Because such re-endothelialization is dependent on rapi d formation of strong endothelial cell-matrix interactions, experiment s were performed to identify the extracellular matrix that provided en dothelial cells with the greatest resistance to detachment by a shear stress in the least amount of time. MATERIALS AND METHODS: Rabbit micr ovascular endothelial cells were plated onto glass slides coated with collagen, laminin, vitronectin, or fibronectin. After allowing 5-45 mi nutes for cell adhesion, each slide was placed in a parallel plate cha mber, and the number of cells present before and after exposure of the cells to shear stresses (1-25 dynes/cm(2)) were counted. RESULTS: End othelial cell retention to the matrix-coated slides was time and matri x dependent. The percentages of endothelial cells retained after adhes ion times of 5, 15, 30, and 45 minutes followed by exposure to 15 dyne s/cm(2) were 9%, 20%, 32%, and 38%* for collagen; 7%, 20%, 36%*, and 49% for laminin; 35%, 47%, 62%, and 76%* for vitronectin; and 64%, 58 %, 71%, and 78% for fibronectin, respectively (P <.05 versus 5 minute s adhesion). Similar results were obtained for lower and higher shear stresses, indicating that cell retention was independent of shear stre ss above 1 dyne/cm(2). CONCLUSIONS: The resistance of freshly adherent endothelial cells to detachment by shear stress is matrix- (fibronect in similar or equal to vitronectin > laminin similar or equal to COL) and time-dependent. Fibronectin provided the greatest cell retention i n the least amount of time.