School of Physics, University of Sydney, New South Wales 2006, Australia.
Proc Natl Acad Sci U S A. 2011 Aug 30;108(35):14405-10. doi: 10.1073/pnas.1103277108. Epub 2011 Aug 15.
Immobilizing a protein, that is fully compatible with the patient, on the surface of a biomedical device should make it possible to avoid adverse responses such as inflammation, rejection, or excessive fibrosis. A surface that strongly binds and does not denature the compatible protein is required. Hydrophilic surfaces do not induce denaturation of immobilized protein but exhibit a low binding affinity for protein. Here, we describe an energetic ion-assisted plasma process that can make any surface hydrophilic and at the same time enable it to covalently immobilize functional biological molecules. We show that the modification creates free radicals that migrate to the surface from a reservoir beneath. When they reach the surface, the radicals form covalent bonds with biomolecules. The kinetics and number densities of protein molecules in solution and free radicals in the reservoir control the time required to form a full protein monolayer that is covalently bound. The shelf life of the covalent binding capability is governed by the initial density of free radicals and the depth of the reservoir. We show that the high reactivity of the radicals renders the binding universal across all biological macromolecules. Because the free radical reservoir can be created on any solid material, this approach can be used in medical applications ranging from cardiovascular stents to heart-lung machines.
将与患者完全兼容的蛋白质固定在生物医学设备的表面上，应该可以避免炎症、排斥或过度纤维化等不良反应。需要一种能够强烈结合但不会使相容蛋白质变性的表面。亲水表面不会诱导固定蛋白质变性，但对蛋白质的结合亲和力较低。在这里，我们描述了一种能量离子辅助等离子体工艺，该工艺可以使任何表面亲水，同时能够共价固定功能生物分子。我们表明，修饰会产生自由基，这些自由基从下面的储层迁移到表面。当它们到达表面时，自由基与生物分子形成共价键。溶液中蛋白质分子的动力学和数密度以及储层中的自由基控制形成完全共价结合的蛋白质单层所需的时间。共价结合能力的保质期受自由基的初始密度和储层深度的控制。我们表明，自由基的高反应性使结合具有普遍性，适用于所有生物大分子。由于自由基储层可以在任何固体材料上创建，因此该方法可用于从心血管支架到心肺机等医疗应用。
