Peptide-Coated Vascular Grafts: An In Vivo Study in Sheep
The purpose of this study was to evaluate the amount of neo-intimal tissue in-growth present at the arterial and venous sides of the anastomosis and the degree of endothelial cell lining of the graft lumen in sheep using commercial vascular grafts coated with the P15 cell-binding peptide. Methods:
ePTFE vascular grafts were coated with the cell-binding P15 peptide using a newly developed plasma surface treatment method. 4 P15-treated grafts and 2 control grafts were implanted as arterio-venous fistulas between the femoral artery and vein and between the carotid artery and jugular vein in 2 sheep. 1 animal was euthanized after 14 days and the other animal after 28 days. The grafts along with the connecting arteries and veins were explanted and evaluated for the length of tissue in-growth along the luminal surface of the ePTFE graft from the anastomosis at the arterial and venous sides. Intimal thickness was carefully measured. Scanning electronic microscopy (SEM) was used to confirm the endothelial cell lining. Results:
The study showed a significant difference (p < 0.05) in intimal thickness between the coated and uncoated grafts in the venous side of the anastomosis. The average intimal thickness of coated samples (551 m) was 3 times thinner than that of uncoated ones (1657 m). The endothelial cell lining appeared to be thicker, and its coverage was more uniform for the peptide-coated grafts than the uncoated ones. Overall, there was more neo-intimal tissue in-growth at the venous side than the arterial side of the anastomosis. The intima at the venous side was also thicker and more bulky compared to the arterial side. Conclusion:
This study has demonstrated that P15-coated ePTFE grafts had less intimal tissue in-growth developed at the venous side of the anastomosis than the uncoated ePTFE grafts. The degree of endothelial cell lining for coated samples was also higher than uncoated ones, which is consistent with our in vitro studies using human umbilical vein endothelial cells. P15-coated ePTFE graft materials had significantly improved cell adhesion, proliferation, and migration in vitro over uncoated ePTFE.
Document Type: Research Article
Affiliations: InCube, Inc., Menlo Park
Publication date: 2004-01-01