Abstract 175: Efficacy of Biomimetic Peptide-Fluorosurfactant Polymer Coated Expanded Poly(tetrafluoroethylene) Vascular Grafts in a Porcine Carotid Artery Interposition Model

Abstract

Objectives Vascular grafts currently see limited use in small diameter applications due to the prevalence of thrombosis. Patency of ePTFE grafts could be improved by reducing thrombosis via an endothelial cell specific peptide fluorosurfactant polymer (FSP) coating. Methods In this study, ePTFE grafts were coated with cRRE-FSP, RGD-FSP, or Maltose-7 (M7)-FSP, sodded with porcine pulmonary artery endothelial cells (PPAECs), and evaluated in vivo in a porcine carotid artery interposition model. Grafts were excised after one month and evaluated by quantifying thrombosis and intimal hyperplasia and by qualitatively examining inflammation, smooth muscle cell infiltration, and endothelialization. Results Angiography of the grafts after one month showed at least partial patency in all grafts with the exception of one RGD-coated and one uncoated graft. Immunofluorescent staining of cell-sodded grafts showed a complete endothelial layer of adherent and spread PPAECs. Thrombus formation was present in two uncoated grafts and one RGD-coated graft. Intimal hyperplasia comprised mostly of smooth muscle cells was present in all grafts, but developed to the highest extent in RGD-coated grafts. Mean graft occlusion in M7 (24.7%) and cRRE-coated grafts (25.1%) was reduced by half compared to uncoated (58.5%) and RGD-coated grafts (53.9%). Conclusions Increased intimal hyperplasia in RGD grafts suggests that RGD, a prominent cell adhesion peptide, may facilitate ingrowth of more smooth muscle cells compared to the other grafts. These results show that cRRE-FSP coating of ePTFE grafts may reduce thrombosis, making it a promising candidate for improving graft patency.