Centre LOEX de l'Université Laval, Génie tissulaire et régénérationand Département de Chirurgie, Faculté de Médecine, Université Laval Québec, Québec, Canada.
Tissue Eng Part A. 2011 Aug;17(15-16):2049-59. doi: 10.1089/ten.TEA.2010.0613. Epub 2011 May 19.
There is a clinical need for better blood vessel substitutes, as current surgical procedures are limited by the availability of suitable autologous vessels and suboptimal behavior of synthetic grafts in small caliber arterial graft (<5 mm) applications. The aim of the present study was to compare the mechanical properties of arterial and venous tissue-engineered vascular constructs produced by the self-assembly approach using cells extracted from either the artery or vein harvested from the same human umbilical cord. The production of a vascular construct comprised of a media and an adventitia (TEVMA) was achieved by rolling a continuous tissue sheet containing both smooth muscle cells and adventitial fibroblasts grown contiguously in the same tissue culture plate. Histology and immunofluorescence staining were used to evaluate the structure and composition of the extracellular matrix of the vascular constructs. The mechanical strength was assessed by uniaxial tensile testing, whereas viscoelastic behavior was evaluated by stepwise stress-relaxation and by cyclic loading hysteresis analysis. Tensile testing showed that the use of arterial cells resulted in stronger and stiffer constructs when compared with those produced using venous cells. Moreover, cyclic loading demonstrated that constructs produced using arterial cells were able to bear higher loads for the same amount of strain when compared with venous constructs. These results indicate that cells isolated from umbilical cord can be used to produce vascular constructs. Arterial constructs possessed superior mechanical properties when compared with venous constructs produced using cells isolated from the same human donor. This study highlights the fact that smooth muscle cells and fibroblasts originating from different cell sources can potentially lead to distinct tissue properties when used in tissue engineering applications.
临床上需要更好的血管替代品，因为目前的手术方法受到合适的自体血管可用性的限制，并且在小口径动脉移植物 (<5 mm) 应用中，合成移植物的行为也不理想。本研究的目的是比较使用源自同一人脐带的动脉或静脉提取的细胞通过自组装方法生产的动脉和静脉组织工程血管构建体的机械性能。通过滚动连续的组织片来生产包含平滑肌细胞和紧贴在同一组织培养板上生长的外膜成纤维细胞的组织片，从而构建血管构建体。组织学和免疫荧光染色用于评估血管构建体的细胞外基质的结构和组成。通过单轴拉伸测试评估机械强度，通过逐步应力松弛和循环加载滞后分析评估粘弹性行为。拉伸测试表明，与使用静脉细胞相比，使用动脉细胞可产生更强和更硬的构建体。此外，循环加载表明，与静脉构建体相比，使用动脉细胞生产的构建体在相同应变下能够承受更高的负载。这些结果表明，可以从脐带中分离出细胞来生产血管构建体。与使用同一供体分离的细胞生产的静脉构建体相比，动脉构建体具有更好的机械性能。本研究强调了一个事实，即源自不同细胞来源的平滑肌细胞和成纤维细胞在用于组织工程应用时可能导致不同的组织特性。
