Faculty of Pharmacy, Max Mousseron Institute of Biomolecules, UMR CNRS 5247, University Montpellier 1, Team CRBA, 15 Avenue Charles Flahault, BP 14491, 34093, Montpellier Cedex 5, France.
J Biomater Sci Polym Ed. 2013;24(13):1499-518. doi: 10.1080/09205063.2013.772045. Epub 2013 Mar 6.
In literature, contacts between pegylated compounds and blood proteins are generally discussed in terms of excluded volume-related repulsions although adsorption and compatibility have been reported for some of these proteins occasionally. The major problem to investigate the behavior of blood in contact with pegylated surfaces is the complexity of the medium and especially the presence of albumin in large excess. In a model approach, optical waveguide lightmode spectroscopy (OWLS) was used to monitor the fate of albumin, fibrinogen, and γ-globulins at physiological concentrations in pH = 7.4 isotonic HEPES buffer after contact with SiTiO2 chips coated with diblock poly(DL-lactic acid)-block-poly(ethylene oxide)s and triblock poly(DL-lactic acid)-block-poly(ethylene oxide)-block-poly(DL-lactic acid) copolymers. Corresponding homopolymers were used as controls. The three protein systems were investigated separately, as a mixture and when added successively according to different orders of addition. OWLS gave access to the mass and the thickness of adhering protein layers that resist washing with HEPES buffer. Protein depositions were detected regardless of the presence of poly(ethylene glycol) segments on surfaces. Adsorption depended on the protein, on the surface and also on the presence of the other proteins. Unexpectedly any surface coated with a layer of adsorbed albumin prevented deposition of other proteins, including albumin itself. This outstanding finding suggests that it was the presence of albumin adsorbed on a surface, pegylated or not, that made that surface compatible with other proteins. As a consequence, dipping a device to be in contact with the blood of a patient in a solution of albumin could be a very simple means to avoid further protein deposition and maybe platelets adhesion after in vivo implantation.
在文献中，通常根据排除体积相关排斥来讨论聚乙二醇化化合物与血液蛋白之间的相互作用，尽管偶尔也有报道称这些蛋白质中的一些会发生吸附和相容性。研究与聚乙二醇化表面接触的血液行为的主要问题是介质的复杂性，特别是白蛋白大量过剩的存在。在一种模型方法中，用光波导光模式光谱（OWLS）监测在生理浓度下，白蛋白、纤维蛋白原和γ-球蛋白在 pH = 7.4 的等渗 HEPES 缓冲液中与涂有二嵌段聚（DL-乳酸）-嵌段-聚（氧化乙烯）和三嵌段聚（DL-乳酸）-嵌段-聚（氧化乙烯）-嵌段-聚（DL-乳酸）共聚物的 SiTiO2 芯片接触后的命运。相应的均聚物被用作对照。三个蛋白质系统分别进行了研究，作为混合物，并根据不同的添加顺序依次添加。OWLS 可以获得抵抗 HEPES 缓冲液洗涤的附着蛋白质层的质量和厚度。无论表面是否存在聚乙二醇段，都检测到蛋白质沉积。吸附取决于蛋白质、表面以及其他蛋白质的存在。出乎意料的是，任何涂有吸附白蛋白层的表面都阻止了其他蛋白质的沉积，包括白蛋白本身。这一惊人的发现表明，正是吸附在表面上的白蛋白的存在，无论是否聚乙二醇化，使表面与其他蛋白质相容。因此，将与患者血液接触的设备浸入白蛋白溶液中可能是一种非常简单的方法，可以避免在体内植入后进一步的蛋白质沉积和可能的血小板黏附。
