GROWTH FACTOR MEDIATION OF HEALING OF VASCULAR GRAFTS

目前动脉粥样硬化的所有治疗性介入方式 结果令人失望，主要是由于血液/动脉壁， 血液/材料界面现象，导致早期和早期的高比率 血栓形成和晚期肌内膜增生。这两种失效模式 成功招募一名正常运作的 内皮细胞（EC）单层。我们的实验室开发了一个系统， 所述EC化学引诱物和促有丝分裂剂可以浸渍在 以缓释生物活性的方式将聚四氟乙烯 （ePTFE）移植物。我们已经证明，该系统诱导体内a 跨间质毛细血管向内生长和EC显著增加 增殖产生快速发展的汇合EC层在 界面没有随后持续的内皮下细胞增殖或 内膜增生 我们在本提案中的目标是扩展这些数据，以优化 应用于合成血管的生长因子（GF）递送系统 并将其应用扩展到机械后的动脉 去内皮化我们将联合收割机与电子商务相结合 使用新的系统进行移植，在该系统中，细胞以高密度接种， 含有GF的悬浮液中的密度。EC和平滑肌细胞（SMC） 生长和功能特性将通过系统地确定， 信息和蛋白质水平以及细胞外基质成分 定量。移植的EC将是野生型的和遗传性的。 修饰并确定基因产物递送的功效。的 该建议的具体目标是： 所述细胞生长调节物质可在生物活性制剂中获得 最大化血管移植物的内皮化， 内皮化动脉; 2）确定优化的 生长因子缓释系统对ePTFE体内内皮化的影响 移植物和去内皮化的动脉，并系统地 研究向内生长的EC和SMC的功能特征;以及 3)研究该技术在基因治疗中的应用 使用首先用报告基因转染然后用基因转染的EC 编码具有缀合的分泌信号序列的FGF-1。该特定 aim可能导致更快的内皮化，并将记录 这种方法在基因治疗中的适用性。最终 该提案的目的是提高小剂量的临床疗效。 直径血管移植物，以优化愈合，减少再狭窄 动脉内膜切除术和血管成形术，并提供最佳的 转基因EC的应用系统， 基因产物递送。

All current therapeutic interventional modalities in atherosclerosis have had disappointing results due largely to blood/arterial wall and blood/material interfacial phenomena resulting in high rates of both early thrombosis and late myointimal hyperplasia. Both failure modes would likely be reduced by successful recruitment of a normal functioning endothelial cell (EC) monolayer. Our laboratory has developed a system by which EC chemoattractant and mitogenic agents can be impregnated in a slowly released bioactive fashion into expanded polytetrafluoroethylene (ePTFE) grafts. We have shown that this system induces in vivo a significant increase in transinterstitial capillary ingrowth and EC proliferation yielding a rapidly developed confluent EC layer at the interface with no later persistent subendothelial cell proliferation or intimal hyperplasia. Our objectives in this proposal are to expand upon this data to optimize the growth factor (GF) delivery system as applied to synthetic vascular grafts and to extend its application to arteries following mechanical deendothelialization. We will combine these techniques with EC transplantation using a novel system in which the cells are seeded at high density within suspensions containing GFs. EC and smooth muscle cell (SMC) growth and functional characteristics will by systematically determined at the message and protein levels and extracellular matrix components quantitated. Transplanted ECs will be both wild-type and genetically modified and the efficacy of gene product delivery determined. The Specific Aims of this proposal are: l) to optimize the delivery system by which cell growth modulating substances are made available in a bioactive form to maximize endothelialization of vascular grafts and de- endothelialized arteries; 2) to determine the effect of the optimized growth factor delivery system on endothelialization in vivo of ePTFE grafts and de-endothelialized arteries in dogs and to systematically investigate the functional characteristics of ingrowing ECs and SMCs; and 3) to investigate the application of this technology for gene therapy using ECs transfected first with reporter genes and then with the gene encoding FGF- l with a conjugated secretory signal sequence. This specific aim may result in still more rapid endothelialization and will document the applicability of this approach for use in gene therapy. The ultimate goals of this proposal are to improve the clinical efficacy of small diameter vascular grafts, to optimize healing with diminished restenosis of endarterectomy and angioplasty procedures, and to provide an optimal system for the application of genetically modified ECs for purposes of gene product delivery.