School of Biomedical Engineering, Department of Chemical Engineering, McMaster University, Hamilton, Ontario, Canada L8S 4L8.
Colloids Surf B Biointerfaces. 2010 Dec 1;81(2):389-96. doi: 10.1016/j.colsurfb.2010.07.024. Epub 2010 Jul 15.
In this work, we hypothesize that a surface modified with both polyethylene glycol (PEG) and hirudin may provide a non-fouling, thrombin-neutralizing surface suitable for blood contacting applications. With gold as a model substrate we used two different approaches to the preparation of such a surface: (1) a "direct" method in which PEG was conjugated to hirudin and the conjugate was then immobilized on the gold; (2) a "sequential" method in which PEG was immobilized on the gold and hirudin then attached to the immobilized PEG. The surfaces were characterized by water contact angle, ellipsometry and XPS. The biological properties were investigated by measuring protein adsorption (fibrinogen and thrombin) from buffer and plasma; thrombin inhibition was measured using a chromogenic substrate assay. Hirudin immobilization was found to be more efficient on surfaces prepared by the "direct" method. "Sequential" surfaces, however, despite having a lower density of hirudin, showed greater biological activity (thrombin binding and inhibition).
在这项工作中，我们假设通过同时修饰聚乙二醇（PEG）和水蛭素，可以得到一种抗污染、抗凝血酶的表面，适用于与血液接触的应用。我们以金作为模型基底，使用两种不同的方法来制备这种表面：（1）“直接”法，其中 PEG 与水蛭素偶联，然后将偶联物固定在金上；（2）“顺序”法，其中 PEG 固定在金上，然后将水蛭素连接到固定的 PEG 上。通过水接触角、椭圆偏振术和 XPS 对表面进行了表征。通过测量缓冲液和血浆中的蛋白质吸附（纤维蛋白原和凝血酶）来研究生物性质；使用显色底物测定法测量凝血酶抑制。发现“直接”法制备的表面更有利于水蛭素的固定。然而，“顺序”表面尽管水蛭素密度较低，但表现出更大的生物活性（凝血酶结合和抑制）。
