Division of Theoretical Chemistry, Lund University, POB 124, SE-221 00 Lund, Sweden 2 Applied Chemistry, Chemistry and Chemical Engineering, Chalmers University of Technology, Chalmersplatsen 4, SE-412 96 Göteborg, Sweden.
Applied Chemistry, Chemistry and Chemical Engineering, Chalmers University of Technology,Chalmersplatsen 4, SE-412 96 Göteborg, Sweden.
Biomolecules. 2020 Mar 6;10(3):413. doi: 10.3390/biom10030413.
When a biomaterial is inserted into the body, proteins rapidly adsorb onto its surface, creating a conditioning protein film that functions as a link between the implant and adhering cells. Depending on the nano-roughness of the surface, proteins will adsorb in different amounts, with different conformations and orientations, possibly affecting the subsequent attachment of cells to the surface. Thus, modifications of the surface nanotopography of an implant may prevent biomaterial-associated infections. Fibrinogen is of particular importance since it contains adhesion epitopes that are recognized by both eukaryotic and prokaryotic cells, and can therefore influence the adhesion of bacteria. The aim of this study was to model adsorption of fibrinogen to smooth or nanostructured silica surfaces in an attempt to further understand how surface nanotopography may affect the orientation of the adsorbed fibrinogen molecule. We used a coarse-grained model, where the main body of fibrinogen (visible in the crystal structure) was modeled as rigid and the flexible α C-chains (not visible in the crystal structure) were modeled as completely disordered. We found that the elongated fibrinogen molecule preferably adsorbs in such a way that it protrudes further into solution on a nanostructured surface compared to a flat one. This implicates that the orientation on the flat surface increases its bio-availability.
当生物材料被植入体内时，蛋白质会迅速吸附在其表面，形成一层条件化的蛋白质膜，作为植入物和附着细胞之间的连接。根据表面的纳米粗糙度，蛋白质的吸附量会有所不同，其构象和取向也会不同，这可能会影响随后细胞对表面的附着。因此，对植入物表面纳米形貌的修饰可以防止与生物材料相关的感染。纤维蛋白原尤为重要，因为它包含被真核细胞和原核细胞识别的黏附表位，因此可以影响细菌的黏附。本研究的目的是模拟纤维蛋白原在光滑或纳米结构二氧化硅表面的吸附，以进一步了解表面纳米形貌如何影响吸附的纤维蛋白原分子的取向。我们使用了粗粒化模型，其中纤维蛋白原的主体（在晶体结构中可见）被建模为刚性的，而柔性的αC-链（在晶体结构中不可见）被建模为完全无序的。我们发现，与在平面表面上相比，纤维蛋白原这种长形分子更倾向于以一种方式吸附，即在纳米结构表面上进一步突出到溶液中。这意味着在平面表面上的取向增加了其生物利用度。
