A novel approach via combination of electrospinning and FDM for tri-leaflet heart valve scaffold fabrication
A novel approach via combination of electrospinning and FDM for tri-leaflet heart valve scaffold fabrication
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DOI：
10.1007/s11706-009-0067-3
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发表时间：
2009-12-01
影响因子：
2.7
通讯作者：
Mo, Xiu-mei
中科院分区：
文献类型：
--
作者：
Chen, Rui;Morsi, Yosry;Mo, Xiu-mei
本文提出了一种新的电纺和快速成型（RP）熔融沉积成型（FDM）相结合的方法来制备组织工程心脏瓣膜（TEHV）支架。支架制备包括两个步骤：三叶支架制备和心脏瓣膜环制备。为了模拟天然心脏瓣膜小叶的各向异性力学性能，引入静电纺丝热塑性聚氨酯（ES-TPU）作为三叶支架材料。ES-TPU支架可以制造成具有良好排列的纤维网络，这对于涉及机械各向异性软组织的应用是重要的。我们在变速条件下开发了ES-TPU支架作为心脏瓣膜小叶材料，并通过快速傅立叶变换（FFT）测量了纤维排列。通过使用FFT将相对对齐值分配给电纺基质，可以系统地评估不同的加工变量如何影响支架的结构和材料特性。将TPU以一定浓度悬浮并从1，1，1，3，3，3-六氟-2-丙醇电纺到旋转心轴上（200 - 3000 rpm）。讨论了纤维直径和芯轴转速对支架形态和力学各向异性的影响。诱导不同程度的各向异性赋予独特的材料性能的静电纺丝支架。应用有限差分法对人工心脏瓣膜进行了动态优化设计。使用pro-engineer基于最佳血液动力学分析构建3D心脏瓣膜环的制造，并将其转换为STL文件格式。然后从PCL创建模型，PCL与电纺纳米纤维小叶缝合并粘合。这种方法被证明是一种很有前途的制造工艺，在制造一个专门设计的移植正确的物理和机械性能。
In this paper, a novel combination method of electrospinning and rapid prototyping (RP) fused deposition modeling (FDM) is proposed for the fabrication of a tissue engineering heart valve (TEHV) scaffold. The scaffold preparation consisted of two steps: tri-leaflet scaffold fabrication and heart valve ring fabrication. With the purpose of mimicking the anisotropic mechanical properties of the natural heart valve leaflet, electrospun thermoplastic polyurethane (ES-TPU) was introduced as the tri-leaflet scaffold material. ES-TPU scaffolds can be fabricated to have a well-aligned fiber network, which is important for applications involving mechanically anisotropic soft tissues. We developed ES-TPU scaffolds as heart valve leaflet materials under variable speed conditions and measured fiber alignment by fast Fourier transform (FFT). By using FFT to assign relative alignment values to an electrospun matrix, it is possible to systematically evaluate how different processing variables affect the structure and material properties of a scaffold. TPU was suspended at certain concentrations and electrospun from 1,1,1,3,3,3-hexafluoro-2-propanol onto rotating mandrels (200-3000 rpm). The scaffold morphological property and mechanical anisotropic property are discussed in the paper as a function of fiber diameter and mandrel RPM. The induction of varying degrees of anisotropy imparted distinctive material properties to the electrospun scaffolds. A dynamic optimum design of the heart valve ring graft was constructed by FDM. Fabrication of a 3D heart valve ring was constructed using pro-engineer based on optimum hemodynamic analysis and was converted to an STL file format. The model was then created from PCL which was sewed and glued with electrospun nanofibrous leaflets. This proposed method was proven as a promising fabrication process in fabricating a specially designed graft with the correct physical and mechanical properties.