Tissue engineering of small diameter vascular graft

小直径血管移植物的组织工程

• 批准号: 6802018
• 负责人: Changyi Chen
• 金额: $ 49.35万
• 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/6802018
• 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）：目的是制造一个真正稳定的人造血管，不含合成材料，需要内皮细胞和平滑肌细胞以及成纤维细胞侵入和生长到支架中。这既可以通过植入后的邻近组织或循环细胞在体内实现，也可以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，否则可能破坏其壁，导致长期动脉瘤形成或引发急性血栓形成。基于这些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（EPC）播种，可以从猪颈动脉中组织工程化一种新型的小直径血管移植物；这种接枝可以保持其力学性能和自然顺应性；降低宿主免疫反应；提供抗凝表面；并加速血管细胞的生长和重塑，从而在体内保持长期效力。下面提出了三个具体目标来验证我们的中心假设：目标1：确定脱细胞肝素化猪颈动脉移植物（D-H移植物）的机械特性、自然顺应性、宿主免疫反应和抗凝特性。我们将验证D-H移植物可能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。包括体外和动物模型。颈动脉搭桥手术将在狗（异种环境）和猪（异体环境）中使用D-H移植物。目的2：探讨bFGF结合D-H移植物对血管细胞生长和移植物再生的影响。我们将验证bFGF与D-H移植物结合可能促进血管细胞生长和移植物再生，从而加速血管愈合和重塑的假设。在体外研究bFGF的结合和释放特性以及对细胞增殖和抗凝的影响。将研究bFGF结合D-H移植物的体内性能。目的3：研究巨噬细胞内皮祖细胞（EPC）的细胞增殖分化特征及其在bFGF结合的D-H移植物中的应用。我们将验证bFGF结合的D-H移植物可以增强EPC增殖和分化的假设，并且与未植入的移植物相比，EPC植入的bFGF结合的D-H移植物可能具有更好的愈合和重塑特性。将从狗或猪外周血中分离和鉴定EPC。探讨bFGF和血流动力学对EPC分化和增殖的影响。将研究EPC种子结合bFGF的D-H移植物的体内性能。这项研究代表了包括组织工程、细胞和分子生物学以及动物模型在内的多学科方法。本研究的成功将直接指导组织工程小直径血管移植的临床应用。