Noel Samantha, Liberelle Benoît, Yogi Alvaro, Moreno Maria J, Bureau Martin N, Robitaille Lucie, De Crescenzo Gregory
Department of Chemical Engineering, Groupe de Recherche en Sciences et Technologies Biomédicales, Bio-P2 Research Unit, École Polytechnique de Montréal, P.O. Box 6079, succ. Centre-Ville, Montréal, QC, Canada H3C 3A7.
J Mater Chem B. 2013 Jan 14;1(2):230-238. doi: 10.1039/c2tb00082b. Epub 2012 Nov 1.
Bioengineering approaches have been intensively applied to create small diameter vascular grafts using artificial materials. However, a fully successful, high performing and anti-thrombogenic structure has not been achieved yet. In this study, we present the first step of a process aiming at biofunctionalizing previously designed compliant polyethylene terephthalate (PET) scaffolds (Moreno et al., 2011). The main challenge of such a surface modification is to prevent the bulk polymer from any damage, so that it preserves the mechanical properties that the structures have been designed for. In that endeavor, an aminated long-chain polymer (polyvinylamine, PVAm) was used as an aminolysis reagent to get amine (-NH) moieties only on the very surface of PET. Different reaction conditions were assayed, leading to a large range of amino group densities associated with slight variations of the planar tensile properties. These results were in stark contrast with those generated with a common small diamine substrate (ethylenediamine, EtDA), as the latter yielded a strong degradation of the mechanical properties for comparable amine densities. Tubular mechanical assays were then carried out on PVAm-functionalized PET scaffolds. The latter showed a compliance match with arteries under the chosen reaction conditions, as initially observed for pristine PET tubular scaffolds.
生物工程方法已被广泛应用于使用人工材料制造小直径血管移植物。然而，尚未实现完全成功、高性能且抗血栓形成的结构。在本研究中，我们展示了旨在对先前设计的柔顺聚对苯二甲酸乙二酯（PET）支架进行生物功能化的过程的第一步（莫雷诺等人，2011年）。这种表面改性的主要挑战是防止本体聚合物受到任何损害，从而保持结构所设计的机械性能。为此，一种胺化长链聚合物（聚乙烯胺，PVAm）被用作氨解试剂，以使胺基（-NH）仅出现在PET的非常表面上。测定了不同的反应条件，导致一系列与平面拉伸性能的轻微变化相关的氨基密度。这些结果与使用常见的小 diamine 底物（乙二胺，EtDA）产生的结果形成鲜明对比，因为后者在可比的胺密度下导致机械性能的强烈降解。然后对PVAm功能化的PET支架进行管状力学测定。后者在所选反应条件下显示出与动脉的顺应性匹配，这与最初观察到的原始PET管状支架情况相同。
