Placement of endothelial cells on the luminal surface of denuded arteries in vitro and in vivo

PURPOSE: Experiments were performed to determine if the percutaneous placement of endothelial cells on denuded arterial surfaces is feasible. MATERIALS AND METHODS: For in vitro adhesion assays, rabbit microvascular endothelial cells were stained with a fluorescent marker and placed on the luminal surface of disks of denuded rabbit aorta. At varying times thereafter, the nonadherent cells were removed, and the adherent cells were quantitated with use of fluorescence microscopy, For in vivo studies, angioplasty was performed on external iliac arteries in five rabbits, and a double-balloon catheter, positioned at the dilatation site, was used to deliver fluorescent rabbit microvascular endothelial cells. Ten minutes (n = 2), 1 hour (n = 2), 1 day (n = 1), or 3 days (n = 1) after cell placement, the number of fluorescent cells remaining on each artery was determined. RESULTS: In vitro rabbit microvascular endothelial cell attachment was (a) serum-dependent, peaking with media containing 25% autologous serum; (b) time-dependent, peaking at 30 minutes; and (c) cell density-dependent. In vivo rabbit microvascular endothelial cell attachment was (a) noncircumferential, (b) appeared to be gravity-dependent, and (c) appeared unchanged over 3 days with respect to number of cells per cross-section and length of artery having endothelium. CONCLUSIONS: Percutaneous delivery of endothelial cells onto denuded arterial surfaces with use of optimal conditions is feasible and these cells remain adherent for at least 3 days.