Endothelial Progenitor Cell Seeded Self-Expanding Vascular Stent

描述（由申请人提供）：目的：本研究的目的是开发一种将自体外周血来源的内皮祖细胞（EPC）内衬于自膨式镍钛合金支架的技术，以减少支架内再狭窄和血栓形成的常见和潜在破坏性并发症。镍钛合金支架用于治疗外周血管疾病患者的血管狭窄，到2020年，这种疾病将影响美国超过2000万患者。目的和方法：本研究的目的是优化一种新技术，用外周血来源的EPC接种镍钛合金支架，并体外评价支架表面的EPC功能。我们计划制造一种创新的镍钛合金输送系统，该系统允许在植入后几分钟内通过在支架外鞘中激光钻孔微孔接种支架，以便在迫使含EPC溶液通过支架侧孔时，利用溶剂拖曳原理将EPC接种在支柱内表面上。我们还将优化支架成像和再压缩方法。In Aim I.B.我们将评估在离体流动回路中在生理剪切应力下镍钛诺支架上的细胞保留，并测试粘附是否由细胞壁磷蛋白介导。In Aim I.C.我们通过用Ionics/Sievers一氧化氮分析仪定量培养基样品中的亚硝酸盐来评估一氧化氮的产生，并通过在不同流动条件下用Western印迹分析支架表面上的EPC来评估血栓调节蛋白的表达。在目标2中，我们将在猪动物模型中测试EPC涂层镍钛合金支架。目标2.A.将使我们能够测试我们的新方法，用荧光标记的EPCs接种镍钛合金支架，并在短期存活研究中将其植入3只试点动物。在目标2.B中，我们将在7只猪的右颈外静脉和左颈外静脉中植入一个EPC涂层支架和一个未涂层支架（对照）。将通过组织形态学半定量分析以及扫描和荧光显微镜检查评价治疗支架和对照支架之间血栓形成和再狭窄的差异。影响：本研究将加深我们对EPCs在剪切应力作用下在镍钛合金表面的功能和粘附机制的理解。如果成功，我们将为一项新技术提供概念验证，这将显著改善自膨式支架的性能，并可能使数百万患者受益。

DESCRIPTION (provided by applicant): Objectives: It is the goal of this study to develop a technology to line self-expanding Nitinol stents with autologous peripheral blood-derived endothelial progenitor cells (EPCs) in order to reduce the common and potentially devastating complications of in-stent restenosis and thrombosis. Nitinol stents are used to treat narrowing of blood vessels in patients with peripheral vascular disease, an illness that will affect over 20 million patients in the U.S. by 2020. Aims and Methods: It is our Aim I in this study to optimize a novel technology to seed Nitinol stents with EPCs derived from peripheral blood and to evaluate EPC function on the stent surface ex vivo. We plan on manufacturing an innovative Nitinol delivery system that allows seeding the stents within minutes of implantation by laser drilling micropores in the outside stent sheath so that EPCs can be seeded on the inside strut surface by using the principle of solvent drag when forcing EPC-containing solution through a stent side- port. We will also optimize stent imaging and re-compressing methods. In Aim I.B. we will assess cell retention on Nitinol stents under physiological shear stress in an ex vivo flow circuit and test whether adhesion is mediated by cell wall phosphoproteins. In Aim I.C. we evaluate nitric oxide production by quantifying nitrite in media samples with an Ionics/Sievers Nitric Oxide Analyzer and thrombomodulin expression by EPCs on the stent surface with Western blot analysis under different flow conditions. In Aim 2, we will test EPC-coated Nitinol stents in a porcine animal model. Aim 2.A. will allow us to test our novel methods of seeding Nitinol stents with fluorescently-labeled EPCs and implanting them into 3 pilot animals in a short-term survival study. Following, in Aim 2.B. we will implant one EPC-coated and one uncoated (control) stent into the right and left external jugular vein of 7 pigs. The differences in thrombosis and restenosis between treated and control stents will be evaluated by histomorphometric semiquantitative analyses, as well as scanning- and fluorescent microscopy. Impact: The knowledge gained in this proposal will deepen our understanding of the function and adhesion mechanism of EPCs on Nitinol under shear stress. If successful, we will have provided proof-of-concept for a novel technology, which will significantly improve the performance of self-expanding stents and may benefit millions of patients.