Aldenhoff Yvette B J, Knetsch Menno L W, Hanssen Johannes H L, Lindhout Theo, Wielders Simone J H, Koole L H Leo H
Center for Biomaterials Reasearch, University of Maastricht, P.O. Box 616, 6200 MD Maastricht, The Netherlands.
Biomaterials. 2004 Jul;25(16):3125-33. doi: 10.1016/j.biomaterials.2003.10.012.
Coiled metallic guidewires find widespread use, for instance in interventional cardiology. It is known that release of heparin from the surface of guidewires is advantageous to prevent formation of thrombotic emboli. New coiled tubular structures, having larger inner and outer diameter as compared to guidewires, are presented. In theory these tubes can be used as interposition vascular grafts. Ten coiled tubes with an internal diameter of 690 microm were made. Five different adherent polymeric coatings with increasing hydrophilicity were used. Five tubes contained heparin in the coating and the other five were unheparinised controls. The five tubes containing heparin were studied with respect to heparin release in vitro (amount released, kinetics), and immobilised heparin that is exposed at the surface. All tubes were studied with a direct cell contact assay using 3T3 mouse fibroblast cells, a dynamic thrombin generation test, and endothelial cell growth onto the coils. It was found that the heparinised tubes lead to very little thrombin formation. It is argued that this is due to heparin that is immobilised and exposed at the inner surface of such tubes. Furthermore the coils showed to be cytocompatible and endothelial cells adhere and proliferate well onto the coils. This concept is believed to hold promise for further development of small vascular grafts.
螺旋金属导丝有着广泛的用途，例如在介入心脏病学领域。已知从导丝表面释放肝素有利于预防血栓性栓子的形成。本文介绍了一种新型的螺旋管状结构，其内径和外径均比导丝大。理论上，这些管子可作为血管移植替代物。制作了十根内径为690微米的螺旋管。使用了五种亲水性逐渐增加的不同附着性聚合物涂层。其中五根管子的涂层中含有肝素，另外五根作为未肝素化的对照。对五根含肝素的管子进行了体外肝素释放（释放量、动力学）以及表面暴露的固定化肝素的研究。所有管子均通过使用3T3小鼠成纤维细胞的直接细胞接触试验、动态凝血酶生成试验以及内皮细胞在螺旋管上的生长情况进行研究。结果发现，肝素化的管子导致的凝血酶形成极少。据认为，这是由于固定在这些管子内表面并暴露在外的肝素所致。此外，螺旋管显示出具有细胞相容性，内皮细胞能够很好地附着并在螺旋管上增殖。这一概念有望推动小型血管移植替代物的进一步发展。
