Coating of Dacron vascular grafts with an ionic polyurethane: a novel sealant with protein binding properties

The purpose of this study was to develop a novel sealant that would seal pr osthetic vascular graft interstices and be accessible for protein binding. Crimped knitted Dacron vascular grafts were cleaned (CNTRL) and hydrolyzed in boiling sodium hydroxide (HYD). These HYD grafts were sealed using an 11 % solids solution of a polyether-based urethane with carboxylic acid groups (PEU-D) via a novel technique that employs both trans-wall and luminal per fusion. Carboxylic acid content, determined via methylene blue dye uptake, was 2.3- and 4.2-fold greater in PEU-D segments (1.0 +/- 0.27 nmol/mg) as c ompared to HYD and CNTRL segments, respectively. Water permeation through P EU-D graft (1.1 +/- 2 ml/cm(2) min(-1)) was comparable to collagen-impregna ted Dacron (9.8 +/- 10 ml/cm(2) min(-1)). Non-specific I-125-albumin (I-125 -Alb) binding to PEU-D segments (18 +/- 3 ng/mg) was significantly lower th an HYD and CNTRL segments. I-125-Alb linkage to PEU-D using the crosslinker EDC resulted in 5.7-fold greater binding (103 +/- 2 ng/mg) than non-specif ic PEU-D controls. However, covalent linkage of I-125-Alb to PEU-D was 4.9- and 5.9-fold less than CNTRL and HYD segments with EDC, respectively. Thus , ionic polyurethane can be applied to a pre-formed vascular graft, seal th e interstices and create "anchor" sites for protein attachment. (C) 2001 El sevier Science Ltd. All rights reserved.