Silver J H, Lewis K B, Ratner B D, Cooper S L
Department of Chemical Engineering, University of Wisconsin, Madison 53706.
J Biomed Mater Res. 1993 Jun;27(6):735-45. doi: 10.1002/jbm.820270606.
Polyurethanes based upon polytetramethylene oxide (PTMO) as the polyol and derivatized with propyl sulfonate functionality pendant from the urethane nitrogen have previously been shown to possess good blood-contacting properties. Other investigators have shown that sulfonated polyurethanes containing polyethylene oxide (PEO) as the soft segment are much more thrombogenic than those containing PTMO as the soft segment. In this article, the surface properties of sulfonated polyurethanes based upon either PTMO or PEO are compared. Dynamic contact angle measurements show a significant decrease in the receding angles of the sulfonated PTMO-containing polyurethane as compared to its nonsulfonated precursor polymer. No significant difference is seen between the receding contact angles of either the sulfonated PEO-based polyurethane or its nonsulfonated analog. Variable-angle electron spectroscopy for chemical analysis (ESCA) studies of sulfonated PTMO-based polyurethane performed at room temperature show that there is a significant decrease in sulfur content at the surface. In contrast, the sulfonated PEO-based polyurethane showed little change in sulfur content with take-off angle. Finally, ESCA studies of freeze-dried surfaces show a significant increase in sulfur near the surface of the sulfonated PTMO-based polymer as compared to vacuum-dried samples but show no such increase for the sulfonated PEO-based polyurethane. It is suggested that the ability of the sulfonate functionality to be expressed at the surface may explain the observed differences in blood compatibility between the sulfonated polyurethanes based upon polyols of varying hydrophilicity.
以聚四亚甲基醚（PTMO）为多元醇并在氨基甲酸酯氮原子上带有丙基磺酸酯官能团衍生化的聚氨酯，此前已被证明具有良好的血液接触性能。其他研究人员表明，以聚环氧乙烷（PEO）为软段的磺化聚氨酯比以PTMO为软段的磺化聚氨酯血栓形成性更强。在本文中，对基于PTMO或PEO的磺化聚氨酯的表面性能进行了比较。动态接触角测量表明，与未磺化的前体聚合物相比，含磺化PTMO的聚氨酯的后退角显著减小。基于磺化PEO的聚氨酯或其未磺化类似物的后退接触角之间没有显著差异。在室温下对基于磺化PTMO的聚氨酯进行的可变角度化学分析电子能谱（ESCA）研究表明，其表面硫含量显著降低。相比之下，基于磺化PEO的聚氨酯的硫含量随出射角变化不大。最后，对冻干表面的ESCA研究表明，与真空干燥样品相比，基于磺化PTMO的聚合物表面附近的硫含量显著增加，但基于磺化PEO的聚氨酯没有这种增加。有人认为，磺酸酯官能团在表面表达的能力可能解释了基于不同亲水性多元醇的磺化聚氨酯在血液相容性方面观察到的差异。
