Vascular grafts made of expanded polytetrafluoroethylene (ePTFE) are widely employed in vascular reconstructive surgery.
While they are successful as replacements for large-diameter blood vessels, ePTFE vascular grafts are unsuitable for smalldiameter
ones because when the internal diameters of the graft are less than 6 mm, they are found to fail without exception due to
blood clot formation. To reduce platelets adhesion onto the ePTFE vascular graft, a novel method of binding of chitosan/heparin
(CS/Hp) complex to the surface of vascular graft was developed. The binding of chitosan was achieved by irradiating with
ultraviolet light the azide modified chitosan that was coated on the ePTFE surface. By forming complex with this coating of
chitosan, heparin was then bonded to the ePTFE surface. In vitro blood compatibility experiments showed that CS/Hp surfacemodified
ePTFE vascular grafts exhibited markedly reduced platelets adhesion. The outstanding performance of these grafts was
further demonstrated by the in vivo experiments, in which they were found to be still unclogged two weeks post-implantation
into dog veins.
Chitosan/heparin complex , UV photosensitive , ePTFE vascular graft , Blood-compatibility