Influence of the aggregation state in solution on the supramolecular organization of adsorbed type I collagen layers
Influence of the aggregation state in solution on the supramolecular organization of adsorbed type I collagen layers
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DOI：
10.1016/j.colsurfb.2004.12.022
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发表时间：
2005-07-10
影响因子：
5.8
通讯作者：
Rouxhet, PG
中科院分区：
文献类型：
--
作者：
Dupont-Gillain, CC;Jacquemart, I;Rouxhet, PG
在过去的几年中，吸附的胶原蛋白被证明形成层与超分子组织取决于基板的表面性质和制备过程。如果胶原蛋白的浓度和吸附的持续时间足够，则形成纤维状胶原蛋白结构，对应于几个分子的组装。与亲水性表面相比，这在疏水性表面上更容易发生。本研究的目的是了解这种纤维状结构的起源，特别是在确定它们是否导致在溶液中形成的原纤维的沉积或在界面处的组件的建设。因此，使用“中性起始”方法，通过将pH 5.8的溶液在37 ℃下老化15分钟、2天或7天，制备具有增加的聚集度的I型胶原溶液。所得到的解决方案被用来调查的影响，胶原蛋白聚集在溶液中的吸附胶原蛋白层的超分子组织，其特征在于通过X-射线光电子能谱和原子力显微镜。选择聚苯乙烯和等离子体氧化聚苯乙烯作为吸附基质。随着胶原在溶液中聚集程度的增加，界面处胶原原纤维的尺寸和密度减小。这是由单体和溶液的聚集体之间的竞争性吸附过程解释的，转向单体的优势。因此游离单体耗尽的更多聚集的溶液表现得像较低浓度的溶液，即导致较低的吸附量和较少的界面处的原纤维形成。这项研究表明，在吸附的胶原蛋白层中观察到的超分子原纤维，特别是在疏水性基材上，在吸附之前，在溶液中不形成，而是通过吸附分子的自由段的组装在界面处形成。(C)2005 Elsevier B. V.保留所有权利。
In the last years, adsorbed collagen was shown to form layers with a supramolecular organization depending on the substrate surface properties and on the preparation procedure. If the concentration of collagen and the duration of adsorption are sufficient, fibrillar collagen structures are formed, corresponding to assemblies of a few molecules. This occurs more readily on hydrophobic compared to hydrophilic surfaces. This study aims at understanding the origin of such fibrillar structures and in particular at determining whether they result from the deposition of fibrils formed in solution or from the building of assemblies at the interface. Therefore, type I collagen solutions with an increasing degree of aggregation were prepared, using the "neutral-start" approach, by ageing pH 5.8 solutions at 37 degrees C for 15 min, 2 or 7 days. The obtained solutions were used to investigate the influence of collagen aggregation in solution on the supramolecular organization of adsorbed collagen layers, which was characterized by X-ray photoelectron spectroscopy and atomic force microscopy. Polystyrene and plasma-oxidized polystyrene were chosen as substrates for the adsorption. The size and the density of collagen fibrils at the interface decreased upon increasing the degree of aggregation of collagen in solution. This is explained by a competitive adsorption process between monomers and aggregates of the solution, turning at the advantage of the monomers. More aggregated solutions, which are thus depleted in free monomers, behave like less concentrated solutions, i.e. lead to a lower adsorbed amount and less fibril formation at the interface. This study shows that the supramolecular fibrils observed in adsorbed collagen layers, especially on hydrophobic substrates, are not formed in the solution, prior to adsorption, but are built at the interface, through the assembly of free segments of adsorbed molecules. (C) 2005 Elsevier B.V. All rights reserved.