Electrospinning-aligned and random polydioxanone-polycaprolactone-silk fibroin-blended scaffolds: geometry for a vascular matrix
Electrospinning-aligned and random polydioxanone-polycaprolactone-silk fibroin-blended scaffolds: geometry for a vascular matrix
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DOI：
10.1088/1748-6041/4/5/055010
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发表时间：
2009-10-01
影响因子：
4
通讯作者：
Bowlin, G. L.
中科院分区：
文献类型：
--
作者：
McClure, M. J.;Sell, S. A.;Bowlin, G. L.
细胞外基质根据组织类型和机械刺激以特定的几何形状排列。对于体内的血管，纤维优先排列在重复力的方向上。静电纺丝是一种可控过程，可以根据所使用的参数导致纤维排列和随机化。在这项研究中，研究了由聚己内酯 (PCL)、聚二氧环己酮 (PDO) 和丝素蛋白以 100:0 和 50:50 的比例混合组成的 PCL: 丝和 PDO: 丝的动脉移植物，以确定纤维是否可以使用每分钟 500 至 8000 转 (RPM) 的心轴转速可控地排列。结果表明，基于扫描电子显微镜图像的快速傅里叶变换，大直径和小直径心轴产生不同程度的纤维排列。单轴拉伸测试通过芯轴转速为 500 和 8000 RPM 时峰值应力、模量和断裂应变的变化进一步证明了支架的各向异性，导致 PCL 的峰值应力和模量随着转速的增加分别增加 5 倍和 4.5 倍。使用动态顺应性、爆破强度和纵向强度对移植物进行了额外的机械测试，结果表明，与较低心轴旋转速度相比，在较高旋转速率下静电纺丝的移植物产生了更硬的导管，其具有较低的顺应性和较高的爆破强度。研究发现支架性能取决于静电纺丝过程中的几个参数：心轴旋转速率、聚合物类型和心轴尺寸。各向异性条件下的血管支架设计提供了有趣的见解并值得进一步研究。
Extracellular matrices are arranged with a specific geometry based on tissue type and mechanical stimulus. For blood vessels in the body, preferential alignment of fibers is in the direction of repetitive force. Electrospinning is a controllable process which can result in fiber alignment and randomization depending on the parameters utilized. In this study, arterial grafts composed of polycaprolactone (PCL), polydioxanone (PDO) and silk fibroin in blends of 100: 0 and 50: 50 for both PCL: silk and PDO: silk were investigated to determine if fibers could be controllably aligned using a mandrel rotational speed ranging from 500 to 8000 revolutions per minute (RPM). Results revealed that large-and small-diameter mandrels produced different degrees of fiber alignment based on a fast Fourier transform of scanning electron microscope images. Uniaxial tensile testing further demonstrated scaffold anisotropy through changes in peak stress, modulus and strain at break at mandrel rotational speeds of 500 and 8000 RPM, causing peak stress and modulus for PCL to increase 5- and 4.5-fold, respectively, as rotational speed increased. Additional mechanical testing was performed on grafts using dynamic compliance, burst strength and longitudinal strength displaying that grafts electrospun at higher rotational rates produced stiffer conduits which had lower compliance and higher burst strength compared to the lower mandrel rotational rate. Scaffold properties were found to depend on several parameters in the electrospinning process: mandrel rotational rate, polymer type, and mandrel size. Vascular scaffold design under anisotropic conditions provided interesting insights and warrants further investigation.