Goodman S L, Albrecht R M
Scanning Microsc. 1987 Jun;1(2):727-34.
Differences in the shape change responses of platelets to various polymers may determine the thrombotic potential of these materials. Substrate-dependent variation in the expression and motility of the platelet fibrinogen receptor may underlie these differences due to this ligand's essential role in platelet aggregation. In this study we examine platelet activation on polyetherurethaneureas (PEUUs) presently being evaluated for vascular prosthetic applications. These polymers are prepared as 50-100nm thin films suitable as substrates for consecutive light microscopy, high voltage electron microscopy (HVEM), and SEM. 18nm colloidal gold coupled to fibrinogen permits visualization of that receptor's motility in living cells by video-enhanced light microscopy. Subsequent HVEM and SEM of identified cells provides correlative ultrastructure and surface morphology. The use of these novel support films coupled with the multiple modes of microscopy and colloidal gold labeled ligands permits in depth study of the molecular biology of cell adhesion to materials with varied, and known, surface properties. The motility of the platelet fibrinogen receptor was related to the extent of cytoskeletal reorganization, which, in turn, was influenced by polymer surface energetics. Platelets adherent to more hydrophobic PEUUs had greater receptor mobility and receptor redistribution than platelets adherent to more hydrophilic PEUUs. The most extensive receptor motility and redistribution was observed on Formvar, a non-PEUU with low surface-water energy, suggesting that additional surface properties are of importance in determining platelet spreading and fibrinogen receptor motility.
血小板对各种聚合物形状变化反应的差异可能决定了这些材料的血栓形成潜力。由于血小板纤维蛋白原受体的表达和运动性存在底物依赖性变化，且该配体在血小板聚集中起关键作用，因此这些差异可能由此产生。在本研究中，我们检测了目前正在评估用于血管假体应用的聚醚聚氨酯脲（PEUUs）上的血小板活化情况。这些聚合物被制备成50 - 100纳米的薄膜，适合作为连续光学显微镜、高压电子显微镜（HVEM）和扫描电子显微镜（SEM）的底物。与纤维蛋白原偶联的18纳米胶体金可通过视频增强光学显微镜观察活细胞中该受体的运动。随后对已识别细胞进行的HVEM和SEM可提供相关的超微结构和表面形态。使用这些新型支撑膜，结合多种显微镜模式和胶体金标记的配体，能够深入研究细胞与具有不同且已知表面特性的材料之间粘附的分子生物学。血小板纤维蛋白原受体的运动与细胞骨架重组的程度相关，而细胞骨架重组又受到聚合物表面能的影响。与粘附在亲水性更强的PEUUs上的血小板相比，粘附在疏水性更强的PEUUs上的血小板具有更大的受体流动性和受体重新分布。在福尔马林（Formvar）上观察到最广泛的受体运动和重新分布，福尔马林是一种具有低表面水能的非PEUU，这表明其他表面特性在决定血小板铺展和纤维蛋白原受体运动方面也很重要。
