Department of Cardiothoracic Surgery, Shanghai Children's Medical Center, Shanghai Jiaotong University School of Medicine, Shanghai 200127, People's Republic of China. These authors contributed equally to this work.
Biomed Mater. 2020 Jul 27;15(5):055010. doi: 10.1088/1748-605X/ab920a.
There is an urgent need to design a tissue-engineered vascular graft that exhibits good biocompatibility and sufficient mechanical strength to repair and facilitate regeneration of defective vascular tissue. It is generally accepted that multi-layer stents can be used to simulate the structure and function of natural blood vessels. Here, we developed a new three-layer tubular graft that is rolled from a single Poly(L-lactide-co-caprolactone) electrospun membrane. We used a new electrospinning technique to place three different structures on a single electrospun membrane such that the stent is comprised of three different layers. The inner layer is dense and suitable for endothelial cell growth, the middle layer is a parallel loose structure suitable for smooth muscle cell growth, and the outer layer is a parallel structure with sparse alternating texture suitable for both smooth muscle cell growth and structural support. The vascular stent has good tensile strength. At the same time, endothelial cells and smooth muscle cells readily proliferate on the material in vitro. In particular, smooth muscle cells grow in parallel on the middle and outer materials. In vivo, all layers of the vascular graft were infiltrated by cells within one week of subcutaneous implantation, indicative of favorable biocompatibility. After a week of subcutaneous implantation, the vascular stent was orthotopically transplanted into the abdominal aorta of Sprague Dawley rats. After ten weeks of transplantation, ultrasound imaging of the abdomen showed vascular patency. The vascular stent was endothelialized, smooth muscle cells readily proliferated, and a large amount of elastic fibers were formed. Therefore, our specially designed tri-layer vascular graft may be of significant benefit in vascular reconstruction.
迫切需要设计一种组织工程血管移植物，该移植物具有良好的生物相容性和足够的机械强度，以修复和促进有缺陷的血管组织再生。人们普遍认为，多层支架可用于模拟天然血管的结构和功能。在这里，我们开发了一种新的三层管状移植物，它是由单个聚（L-丙交酯-共-己内酯）电纺膜卷制而成的。我们使用一种新的电纺技术将三种不同的结构放置在单个电纺膜上，从而使支架由三个不同的层组成。内层致密，适合内皮细胞生长，中层为平行疏松结构，适合平滑肌细胞生长，外层为平行结构，稀疏交替纹理，适合平滑肌细胞生长和结构支撑。血管支架具有良好的拉伸强度。同时，内皮细胞和平滑肌细胞在体外很容易在材料上增殖。特别是，平滑肌细胞在中层和外层材料上平行生长。在体内，植入皮下一周内，血管移植物的所有层都被细胞浸润，表明具有良好的生物相容性。皮下植入一周后，血管支架被原位移植到 Sprague Dawley 大鼠的腹主动脉中。移植十周后，腹部超声成像显示血管通畅。血管支架内皮化，平滑肌细胞容易增殖，形成大量弹性纤维。因此，我们专门设计的三层血管移植物可能在血管重建方面具有重要意义。
