Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, VA 23284-3067, USA.
Acta Biomater. 2010 Jul;6(7):2422-33. doi: 10.1016/j.actbio.2009.12.029. Epub 2010 Jan 11.
Throughout native artery, collagen, and elastin play an important role, providing a mechanical backbone, preventing vessel rupture, and promoting recovery under pulsatile deformations. The goal of this study was to mimic the structure of native artery by fabricating a multi-layered electrospun conduit composed of poly(caprolactone) (PCL) with the addition of elastin and collagen with blends of 45-45-10, 55-35-10, and 65-25-10 PCL-ELAS-COL to demonstrate mechanical properties indicative of native arterial tissue, while remaining conducive to tissue regeneration. Whole grafts and individual layers were analyzed using uniaxial tensile testing, dynamic compliance, suture retention, and burst strength. Compliance results revealed that changes to the middle/medial layer changed overall graft behavior with whole graft compliance values ranging from 0.8 to 2.8%/100 mm Hg, while uniaxial results demonstrated an average modulus range of 2.0-11.8 MPa. Both modulus and compliance data displayed values within the range of native artery. Mathematical modeling was implemented to show how changes in layer stiffness affect the overall circumferential wall stress, and as a design aid to achieve the best mechanical combination of materials. Overall, the results indicated that a graft can be designed to mimic a tri-layered structure by altering layer properties.
在天然动脉中，胶原蛋白和弹性蛋白起着重要作用，为血管提供机械支撑，防止血管破裂，并在脉动变形下促进恢复。本研究的目的是通过制造由聚己内酯（PCL）组成的多层电纺导管来模拟天然动脉的结构，其中添加了弹性蛋白和胶原蛋白，其混合物为 45-45-10、55-35-10 和 65-25-10 的 PCL-ELAS-COL，以展示类似于天然动脉组织的机械性能，同时仍然有利于组织再生。使用单向拉伸测试、动态顺应性、缝合线保持力和爆裂强度对整个移植物和各个层进行了分析。顺应性结果表明，中层/内层的变化改变了整个移植物的行为，整个移植物的顺应性值范围为 0.8 至 2.8%/100mm Hg，而单向结果显示平均模量范围为 2.0 至 11.8MPa。模量和顺应性数据都显示出在天然动脉范围内的值。实施了数学建模以显示层刚度的变化如何影响整个周向壁应力，并作为设计辅助工具来实现材料的最佳机械组合。总体而言，结果表明可以通过改变层的特性来设计模仿三层结构的移植物。
