Graduate School of Systems and Information Engineering, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8573, Japan.
Center for Cybernics Research, University of Tsukuba, Tsukuba, Japan.
Sci Rep. 2021 Jul 19;11(1):14666. doi: 10.1038/s41598-021-94023-9.
Tissue engineered vascular grafts (TEVG) are potentially clear from ethical and epidemiological concerns sources for reconstructive surgery for small diameter blood vessels replacement. Here, we proposed a novel method to create three-layered TEVG on biocompatible glass fiber scaffolds starting from flat sheet state into tubular shape and to train the resulting tissue by our developed bioreactor system. Constructed tubular tissues were matured and trained under 3 types of individual flow programs, and their mechanical and biological properties were analyzed. Training in the bioreactor significantly increased the tissue burst pressure resistance (up to 18 kPa) comparing to untrained tissue. Fluorescent imaging and histological examination of trained vascular tissue revealed that each cell layer has its own individual response to training flow rates. Histological analysis suggested reverse relationship between tissue thickness and shear stress, and the thickness variation profiles were individual between all three types of cell layers. Concluding: a three-layered tissue structure similar to physiological can be assembled by seeding different cell types in succession; the following training of the formed tissue with increasing flow in a bioreactor is effective for promoting cell survival, improving pressure resistance, and cell layer formation of desired properties.
组织工程血管移植物(TEVG)是一种潜在的、无伦理和流行病学问题的来源,可用于小直径血管重建手术的替代。在这里,我们提出了一种从平板状态开始,在生物相容性玻璃纤维支架上创建三层 TEVG 并将其转化为管状结构的新方法,并使用我们开发的生物反应器系统对生成的组织进行训练。构建的管状组织在 3 种单独的流动方案下进行成熟和训练,并对其机械和生物学特性进行了分析。与未经训练的组织相比,在生物反应器中训练显著提高了组织的爆裂压力阻力(高达 18 kPa)。对经过训练的血管组织进行荧光成像和组织学检查表明,每个细胞层对训练流速都有其自身的反应。组织学分析表明,组织厚度与剪切应力之间存在反向关系,并且所有 3 种细胞层之间的厚度变化曲线都是各自独立的。结论:通过依次接种不同类型的细胞,可以组装出类似于生理结构的三层组织结构;在生物反应器中用增加的流量对形成的组织进行后续训练,可有效促进细胞存活、提高抗压力和形成所需特性的细胞层。