Tissue engineering of small caliber vascular grafts
Tissue engineering of small caliber vascular grafts
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DOI：
10.1016/s1010-7940(01)00706-0
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发表时间：
2001-07-01
影响因子：
3.4
通讯作者：
Turina, MI
中科院分区：
文献类型：
--
作者：
Hoerstrup, SP;Zünd, G;Turina, MI
目的：以前的组织工程方法，以创造小口径血管移植物已受到限制的结构和机械的不成熟的建设。本研究使用了一种新型的体外脉冲复制系统，在组织形成过程中提供了一个“仿生”环境，以产生更成熟的可植入血管移植物。方法：血管移植（I.D. 0.5 cm）由新型生物可吸收聚合物（聚乙醇酸/聚-4-羟基丁酸酯）制成，并依次接种绵羊血管肌成纤维细胞和内皮细胞。静态培养4天后，移植物（n = 24）在脉冲复制系统（生物反应器）中体外生长4、7、14、21和28天。对照组（n = 24）在静态培养条件下生长。新组织的分析包括组织学、扫描电子显微镜（SEM）和生化测定（DNA用于细胞含量，5-羟脯氨酸用于胶原）。进行了机械试验，测量爆破压力和缝线固位强度。结果：组织学检查显示所有样本中均存在有活力的致密组织。SEM显示暴露于脉动流14天后移植物的融合光滑内表面。生化分析显示，细胞质量和胶原蛋白的持续增加，到21天相比，在静态控制显着较低的值。脉冲血管移植物的机械性能包括超生理爆破强度和适合外科植入的缝线固位强度。结论：这项研究表明，可行的，手术植入的小口径血管移植物的组织工程的可行性和“仿生”在组织成熟和细胞外基质形成的体外环境的重要影响。(C)2001 Elsevier Science B. V.保留所有权利。
Objective: Previous tissue engineering approaches to create small caliber vascular grafts have been limited by the structural and mechanical immaturity of the constructs. This study uses a novel in vitro pulse duplicator system providing a 'biomimetic' environment during tissue formation to yield more mature, implantable vascular grafts. Methods: Vascular grafts (I.D. 0.5 cm) were fabricated from novel bioabsorbable polymers (polyglycolic-acid/poly-4-hydroxybutyrate) and sequentially seeded with ovine vascular myofibroblasts and endothelial cells. After 4 days static culture, the grafts (n = 24) were grown in vitro in a pulse duplicator system (bioreactor) for 4, 7, 14, 21, and 28 days. Controls (n = 24) were grown in static culture conditions. Analysis of the neo-tissue included histology, scanning electron microscopy (SEM), and biochemical assays (DNA for cell content, 5-hydroxyproline for collagen). Mechanical testing was performed measuring the burst pressure and the suture retention strength. Results: Histology showed viable, dense tissue in all samples. SEM demonstrated confluent smooth inner surfaces of the grafts exposed to pulsatile flow after 14 days. Biochemical analysis revealed a continuous increase of cell mass and collagen to 21 days compared to significantly lower values in the static controls. The mechanical properties of the pulsed vascular grafts comprised supra-physiological burst strength and suture retention strength appropriate for surgical implantation. Conclusions: This study demonstrates the feasibility of tissue engineering of viable, surgically implantable small caliber vascular grafts and the important effect of a 'biomimetic' in vitro environment on tissue maturation and extracellular matrix formation. (C) 2001 Elsevier Science B.V. All rights reserved.