Low Thrombogenicity Coating of Nonwoven PET Fiber Structures for Vascular Grafts

摘要

Vascular PET grafts (Dacron) have shown good performance in large vessels (≥6mm) applications. To address the urgent unmet need for small-diameter (2-6mm) vascular grafts, proprietary high-compliance nonwoven PET fiber structures were modified with various PEG concentrations using PVA as a cross-linking agent, to fabricate non-thrombogenic mechanically compliant vascular grafts. The blood compatibility assays measured through platelet adhesion (SEM and mepacrine dye) and platelet activation (morphological changes, P-selectin secretion, and TXB2 production) demonstrate that functionalization using a 10% PEG solution was sufficient to significantly reduce platelet adhesion/activation close to optimal literature-reported levels observed on carbon-coated ePTFE. Pristine nonwoven polyester (PET) fibers (left) for vascular grafts show human blood platelets adhesion with well-spread and pseudopodia morphologies typical of their activated state. In contrast, nonwoven PEG-grafted amino-modified PET fibers (right) yielded a remarkable suppression of platelets adhesion with neither pseudopodia extension nor platelets deformation, typical of inactivated states of platelets.