Warner Jacob A, Forsyth Bruce, Zhou Fang, Myers Jason, Frethem Chris, Haugstad Greg
Characterization Facility, University of Minnesota, Minneapolis, Minnesota, 55455.
Boston Scientific Corporation, Maple Grove, Minnesota, 55341.
J Biomed Mater Res B Appl Biomater. 2016 Apr;104(3):470-5. doi: 10.1002/jbm.b.33414. Epub 2015 Apr 17.
In the medical device industry, angioplasty balloons have been widely used in the less invasive treatment of heart disease by expanding and relieving clogged structures in various arterial segments. However, new applications using thin coatings on the balloon surface have been explored to enhance therapeutic value in the delivery of pharmaceuticals (drug-elution) or control thermal energy output (RF ablation). In this study, angioplasty balloon materials comprised of poly(ether-block-amide) (Pebax) were investigated via atomic force microscopy (AFM), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and small-angle X-ray scattering (SAXS) to characterize physical properties at the balloon surface that may affect coating adhesion. The soft segment of this Pebax 1074 material is polyethylene oxide (PEO) and the hard segment is nylon-12. The morphology of the hard segments of this block co-polymer are found via AFM stiffness measurements to be (40 ± 20) nm by (300 ± 150) nm and are oriented parallel to the surface of the balloon. SAXS measurements found the lamellar spacing to be (18.5 ± 0.5) nm, and demonstrate a preferential orientation in agreement with TEM and AFM measurements. Fixation of this balloon in resin, followed by cryo-sectioning is shown to provide a novel manner in which to investigate surface characteristics on the balloon such as material or coating thickness as well as uniformity in comparison to the bulk structure. These outputs were deemed critical to improve overall balloon processing such as molding and surface treatment options for robust designs toward better procedural outcomes targeting new therapeutic areas.
在医疗器械行业，血管成形术球囊已广泛应用于心脏病的微创治疗，通过扩张和缓解各动脉段的堵塞结构来实现。然而，人们已经探索了在球囊表面使用薄涂层的新应用，以提高药物递送（药物洗脱）或控制热能输出（射频消融）方面的治疗价值。在本研究中，通过原子力显微镜（AFM）、透射电子显微镜（TEM）、扫描电子显微镜（SEM）和小角X射线散射（SAXS）对由聚（醚 - 嵌段 - 酰胺）（Pebax）组成的血管成形术球囊材料进行了研究，以表征可能影响涂层附着力的球囊表面物理性质。这种Pebax 1074材料的软段是聚环氧乙烷（PEO），硬段是尼龙 - 12。通过AFM刚度测量发现，这种嵌段共聚物硬段的形态为（40±20）nm×（300±150）nm，并且与球囊表面平行排列。SAXS测量发现层间距为（18.5±0.5）nm，并且与TEM和AFM测量结果一致，显示出优先取向。将这种球囊固定在树脂中，然后进行冷冻切片，结果表明这提供了一种新颖的方式来研究球囊表面的特性，如材料或涂层厚度以及与整体结构相比的均匀性。这些结果被认为对于改进整体球囊加工至关重要，例如成型和表面处理选项，以实现针对新治疗领域的稳健设计，从而获得更好的手术效果。
