Burmeister J S, Vrany J D, Reichert W M, Truskey G A
Department of Biomedical Engineering, Duke University, Durham, NC 27708-0281, USA.
J Biomed Mater Res. 1996 Jan;30(1):13-22. doi: 10.1002/(SICI)1097-4636(199601)30:1<13::AID-JBM3>3.0.CO;2-U.
The effect of substrate surface hydrophobicity on fibronectin (Fn) adsorption and endothelial cell adhesion strength was studied. Bovine aortic endothelial cells (BAEC) were plated for 2 h with and without preadsorbed Fn on slides coated with homopolymers and copolymers of hydrophilic polyhydroxyethylmethacrylate (polyHEMA) and hydrophobic polyethylmethacrylate (polyEMA). The polarity of the substrate was determined by Wilhelmy plate contact angle. The amount of adsorbed Fn was determined using 125I-labeled Fn. Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy was used to detect gross conformational changes of adsorbed Fn on polyHEMA or polyEMA. BAEC were cultured in serum-free medium for 2 h and subjected to a brief exposure of laminar flow in a variable-height flow chamber that provided a range of shear stresses of 15-185 dynes/cm2. The critical shear stress to detach 50% of the cells increased with increasing EMA content to a maximum at 20% HEMA/80% EMA copolymer irrespective of the presence of preadsorbed Fn. However, the critical force increased even though there were similar amounts of Fn adsorbed on all substrates. ATR-FTIR spectroscopy showed only minor changes in beta-sheet structure of Fn adsorbed to polyHEMA and polyEMA. These results show that the force to detach cells did not increase solely with increasing amounts of adsorbed Fn; rather, these results indicate a more complex interplay involving both the amount and conformation of adsorbed Fn.
研究了底物表面疏水性对纤连蛋白（Fn）吸附及内皮细胞黏附强度的影响。将牛主动脉内皮细胞（BAEC）接种在涂有亲水性聚甲基丙烯酸羟乙酯（聚HEMA）和疏水性聚甲基丙烯酸乙酯（聚EMA）的均聚物及共聚物的载玻片上，有或没有预吸附Fn的情况下培养2小时。通过威尔海姆板接触角测定底物的极性。使用125I标记的Fn测定吸附的Fn量。采用衰减全反射傅里叶变换红外光谱（ATR-FTIR）检测聚HEMA或聚EMA上吸附的Fn的总体构象变化。将BAEC在无血清培养基中培养2小时，然后在可变高度流动腔中短暂暴露于层流中，该流动腔提供15-185达因/平方厘米的一系列剪切应力。无论是否存在预吸附的Fn，使50%的细胞脱离的临界剪切应力随着EMA含量的增加而增加，在20% HEMA/80% EMA共聚物时达到最大值。然而，尽管所有底物上吸附的Fn量相似，但临界力却增加了。ATR-FTIR光谱显示，吸附到聚HEMA和聚EMA上的Fn的β-折叠结构仅有微小变化。这些结果表明，使细胞脱离的力并非仅随着吸附的Fn量的增加而增加；相反，这些结果表明存在一种更复杂的相互作用，涉及吸附的Fn的量和构象。
