Tissue engineering of small diameter vascular graft

小直径血管移植物的组织工程

• 批准号: 6727255
• 负责人: Changyi Chen
• 金额: $ 48.55万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-09-20 至 2007-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6727255
• 关键词: angiogenesis; biomaterial compatibility; biomaterial interface interaction; biomechanics; biotechnology; blood coagulation; carotid artery; cell differentiation; cell proliferation; coronary bypass; dogs; enzyme linked immunosorbent assay; fibroblast growth factor; flow cytometry; hemodynamics; host organism interaction; immunocytochemistry; polymerase chain reaction; stem cells; swine; tissue engineering; tissue support frame; vascular smooth muscle; western blottings

DESCRIPTION (provided by applicant): The aim to produce a truly stable artificial blood vessel containing no synthetic material requires invasion and in growth of endothelial cell and smooth muscle cells as well as fibroblasts into the scaffold. This can be achieved either in vivo from the adjacent tissue or circulating cells after implantation, or in vitro by means of cultivated cells. Such graft should not induce substantial inflammatory reactions that could either damage its wall, setting the scene for long term aneurysm formation or trigger acute thrombosis. Based on such tissue engineering principles and our preliminary data, we propose a central hypothesis that a novel small diameter vascular graft can be tissue-engineered from the porcine carotid artery by decellularization, heparin covalent linkage, and heparin binding growth factors, and endothelial progenitor cell (EPC) seeding; and this graft may maintain its mechanical property and natural compliance; reduce host immune response; provide anticoagulation surface; and accelerate vascular cell growth and remodeling, thereby maintaining a long term potency in vivo. Three specific aims are proposed below to test our central hypothesis: Aim 1: To determine the mechanical property, natural compliance, host immune response, and anticoagulation property of decellularized-heparinized porcine carotid artery grafts (D-H grafts). We will test the hypothesis that D-H grafts may maintain their mechanical property and natural compliance, provide anticoagulation surface, and reduce host immune response. Both in vitro and animal models are included. Carotid artery bypass surgery using D-H grafts will be performed in dogs (xenogenic setting) and in pigs (allogenic setting). Aim 2: To determine the effect of bFGF binding to D-H grafts on vascular cell growth and repopulation of the grafts. We will test the hypothesis that bFGF binding to D-H grafts may promote vascular cell growth and repopulation of the grafts, thereby accelerating vascular healing and remodeling. Characteristics of bFGF binding and release and effect on cell proliferation and anticoagulation will be investigated in vitro. In vivo performance of bFGF bound D-H grafts will be studied. Aim 3: To characterize cell proliferation and differentiation of EPC and its application with bFGF bound D-H grafts. We will test the hypothesis that bFGF bound D-H grafts may enhance EPC proliferation and differentiation, and EPC seeded bFGF bound D-H grafts may have better healing and remodeling characteristics as compared to un-seeded grafts. EPC will be isolated and characterized from dog or pig peripheral blood. The effect of bFGF and hemodynamics on EPC differentiation and proliferation will be investigated. In vivo performance of EPC seeded bFGF bound D-H grafts will be studied. This study represents a multidisciplinary approach including tissue engineering, cellular and molecular biology, and animal models. Success of this proposal will directly indicate the clinical applications of tissue engineered small diameter vascular grafts.

描述（由申请人提供）：生产不含合成材料的真正稳定的人造血管的目的需要内皮细胞、平滑肌细胞以及成纤维细胞侵入并生长到支架中。这可以通过植入后的邻近组织或循环细胞在体内实现，或者通过培养细胞在体外实现。这种移植物不应引起严重的炎症反应，这种反应可能会损害其壁，为长期动脉瘤形成或引发急性血栓形成奠定基础。基于这样的组织工程原理和我们的初步数据，我们提出了一个中心假设，即通过脱细胞、肝素共价连接、肝素结合生长因子和内皮祖细胞，可以从猪颈动脉组织工程化新型小直径血管移植物（EPC）播种；并且该移植物可以保持其机械性能和自然顺应性；降低宿主免疫反应；提供抗凝表面；并加速血管细胞生长和重塑，从而在体内保持长期效力。下面提出了三个具体目标来检验我们的中心假设： 目标 1：确定脱细胞肝素化猪颈动脉移植物（D-H 移植物）的机械性能、自然顺应性、宿主免疫反应和抗凝性能。我们将测试 D-H 移植物可以保持其机械性能和自然顺应性、提供抗凝表面并减少宿主免疫反应的假设。包括体外模型和动物模型。使用 D-H 移植物的颈动脉搭桥手术将在狗（异种环境）和猪（同种异体环境）中进行。目标 2：确定 bFGF 与 D-H 移植物结合对血管细胞生长和移植物再增殖的影响。我们将检验以下假设：bFGF 与 D-H 移植物结合可能促进血管细胞生长和移植物重新增殖，从而加速血管愈合和重塑。将在体外研究 bFGF 结合和释放的特性以及对细胞增殖和抗凝的影响。将研究 bFGF 结合的 D-H 移植物的体内性能。目标 3：表征 EPC 的细胞增殖和分化及其与 bFGF 结合的 D-H 移植物的应用。我们将测试以下假设：bFGF 结合的 D-H 移植物可以增强 EPC 增殖和分化，并且与未接种的移植物相比，EPC 接种的 bFGF 结合的 D-H 移植物可能具有更好的愈合和重塑特征。 EPC 将从狗或猪的外周血中分离出来并进行表征。将研究 bFGF 和血流动力学对 EPC 分化和增殖的影响。将研究EPC接种的bFGF结合的D-H移植物的体内性能。这项研究代表了一种多学科方法，包括组织工程、细胞和分子生物学以及动物模型。该提案的成功将直接预示着组织工程小直径血管移植物的临床应用。