GROWTH FACTOR MEDIATION OF HEALING OF VASCULAR GRAFTS

目前所有动脉粥样硬化的治疗干预手段都有 结果令人失望，主要是因为血液/动脉壁 血液/材料界面现象导致早期两者的高发生率 血栓形成和晚期肌内膜增生。两种故障模式都将 可能会因成功招募正常功能人员而减少 内皮细胞(EC)单层。我们的实验室通过以下方式开发了一种系统 哪种EC化学诱导剂和有丝分裂试剂可以浸泡在 聚四氟乙烯缓释生物活性成分的研究 (EPTFE)接枝。我们已经证明，这个系统在体内诱导了一个 跨间质毛细血管向内生长和EC显著增加 扩散导致快速发展的融合EC层在 与后来不会持续的内皮下细胞增殖或 内膜增生症。 我们在此提案中的目标是对此数据进行扩展，以优化 生长因子缓释系统在人造血管中的应用 并将其应用于机械移植后的动脉 去内皮化。我们将把这些技术与电子商务结合起来 使用一种新的系统进行移植，在该系统中，细胞在高密度下播种 含有GFS的悬浮液中的密度。血管内皮细胞与平滑肌细胞 生长和功能特性将在以下位置系统确定 信使和蛋白质水平与细胞外基质成分 量化的。移植的ECs将是野生型和遗传型的 对基因产品进行修饰，并测定基因产品的输送效果。这个 这项建议的具体目标是：L)通过以下方式优化交付系统 哪些细胞生长调节物质在生物活性物质中可用 最大限度地使血管移植物内皮化和去内皮化的形式 血管内皮化；2)确定优化后的效果 生长因子缓释系统对ePTFE体内内皮化的影响 犬移植血管和去内皮化动脉，并系统地 研究嵌合内皮细胞和平滑肌细胞的功能特征；以及 3)探索该技术在基因治疗中的应用。 使用先转报告基因后转基因的内皮细胞 用共轭分泌信号序列编码成纤维细胞生长因子-L。这个特定的 AIM可能会导致更快的内皮化，并将记录 这种方法在基因治疗中的适用性。终极的 这项建议的目标是提高Small的临床疗效 直径血管移植物，减少再狭窄，优化愈合 动脉内膜切除术和血管成形术，并提供最佳的 用于以下目的的转基因ECs应用系统 基因产品的传递。

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.