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源性内皮祖细胞（EPCs）与自膨胀镍钛诺支架连接的技术，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。镍钛诺支架用于治疗周围血管疾病患者的血管狭窄，到2020年，美国将有超过2000万患者患有这种疾病。目的和方法：本研究的目的是优化一种将外周血内皮祖细胞植入镍钛诺支架的新技术，并在体外评估内皮祖细胞在支架表面的功能。我们计划制造一种创新的镍钛诺输送系统，通过激光在支架外护套上钻孔微孔，在植入几分钟内播种支架，这样EPCs就可以通过溶剂阻力原理在支架侧孔中播种。我们还将优化支架成像和再压缩方法。在Aim ib中，我们将在体外血流回路中评估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酸化蛋白介导。在Aim I.C.中，我们用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，用Western blot分析不同流动条件下支架表面EPCs的血栓调节蛋白表达。在目标2中，我们将在猪动物模型中测试epc涂层镍钛诺支架。目标2.。将允许我们测试用荧光标记的内皮祖细胞植入镍钛诺支架的新方法，并将其植入3只短期生存研究的试点动物体内。接下来，在第二部分b。我们将一个epc涂层支架和一个未涂层支架（对照）植入7头猪的左右颈外静脉。将通过组织形态学半定量分析以及扫描和荧光显微镜来评估治疗组和对照组支架在血栓形成和再狭窄方面的差异。影响：本提案所获得的知识将加深我们对剪切应力下EPCs在镍钛诺上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证明，这将显著提高自膨胀支架的性能，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. PUBLIC HEALTH RELEVANCE: The goal of this research is to develop a novel technology in order to avoid the dangerous and life-threatening clogging of Nitinol stents. In order to achieve this goal we aim to coat stents with EPCs immediately before implanting them in into the human body. If successful, this will render stents free from obstructions - thus benefitting millions of patients.