Gettens Robert T T, Gilbert Jeremy L
Department of Biomedical and Chemical Engineering, Link Hall 121, Syracuse University, Syracuse, New York 13244, USA.
J Biomed Mater Res A. 2008 Apr;85(1):176-87. doi: 10.1002/jbm.a.31530.
Adsorption of the plasma protein fibrinogen onto electrically polarized 316L stainless steel was observed and quantified using both in situ and ex situ atomic force microscopy (AFM) techniques. Significant differences in fibrinogen adsorption were observed across voltages. Ex situ studies showed significantly lower area coverage (theta) and height of adsorbed Fb on cathodically polarized surfaces when compared to anodically polarized surfaces. Conformational differences in the protein may explain the distinctions in Fb surface area coverage (theta) and height between the anodic and cathodic cases. In situ studies showed significantly slower kinetics of Fb adsorption onto surfaces below -100 mV (vs. Ag/AgCl) compared to surfaces polarized above -100 mV. Electrochemical current density data showed large charge transfer processes (approximately 1 x 10(-5) to 1 x 10(-4) A/cm(2)) taking place on the 316L SS surfaces at voltages below -100 mV (vs. Ag/AgCl). These relatively large current densities point to flux of ionic species away from the surface as a major source of the reduction in adsorption kinetics rather than just hydrophilic or electrostatic effects.
采用原位和非原位原子力显微镜（AFM）技术观察并定量了血浆蛋白纤维蛋白原在电极化316L不锈钢上的吸附情况。观察到不同电压下纤维蛋白原吸附存在显著差异。非原位研究表明，与阳极极化表面相比，阴极极化表面上吸附的纤维蛋白原的面积覆盖率（θ）和高度显著更低。蛋白质的构象差异可能解释了阳极和阴极情况下纤维蛋白原表面积覆盖率（θ）和高度的差异。原位研究表明，与极化电压高于 -100 mV（相对于Ag/AgCl）的表面相比，在 -100 mV（相对于Ag/AgCl）以下的表面上，纤维蛋白原的吸附动力学明显更慢。电化学电流密度数据表明，在电压低于 -100 mV（相对于Ag/AgCl）时，316L不锈钢表面发生了较大的电荷转移过程（约1×10⁻⁵至1×10⁻⁴ A/cm²）。这些相对较大的电流密度表明，离子物种从表面的通量是吸附动力学降低的主要来源，而不仅仅是亲水性或静电效应。
