Yuan Xingyu, Li Wen, Yao Bin, Li Zhao, Kong Deling, Huang Sha, Zhu Meifeng
School of Medicine, Nankai University, Tianjin 300071, China.
College of Life Science, State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials of Ministry of Education, Nankai University, Tianjin 300071, China.
Polymers (Basel). 2022 Mar 28;14(7):1370. doi: 10.3390/polym14071370.
Bionic grafts hold great promise for directing tissue regeneration. In vascular tissue engineering, although a large number of synthetic grafts have been constructed, these substitutes only partially recapitulated the tri-layered structure of native arteries. Synthetic polymers such as poly(l-lactide--ε-caprolactone) (PLCL) possess good biocompatibility, controllable degradation, remarkable processability, and sufficient mechanical strength. These properties of PLCL show great promise for fabricating synthetic vascular substitutes. Here, tri-layered PLCL vascular grafts (TVGs) composed of a smooth inner layer, circumferentially aligned fibrous middle layer, and randomly distributed fibrous outer layer were prepared by sequentially using ink printing, wet spinning, and electrospinning techniques. TVGs possessed kink resistance and sufficient mechanical properties (tensile strength, elastic modulus, suture retention strength, and burst pressure) equivalent to the gold standard conduits of clinical application, i.e., human saphenous veins and human internal mammary arteries. The stratified structure of TVGs exhibited a visible guiding effect on specific vascular cells including enhancing endothelial cell (EC) monolayer formation, favoring vascular smooth muscle cells' (VSMCs) arrangement and elongation, and facilitating fibroblasts' proliferation and junction establishment. Our research provides a new avenue for designing synthetic vascular grafts with polymers.
仿生移植物在引导组织再生方面具有巨大潜力。在血管组织工程中，尽管已经构建了大量合成移植物，但这些替代品仅部分重现了天然动脉的三层结构。诸如聚（L-丙交酯-ε-己内酯）（PLCL）之类的合成聚合物具有良好的生物相容性、可控的降解性、出色的加工性能和足够的机械强度。PLCL的这些特性在制造合成血管替代品方面显示出巨大潜力。在此，通过依次使用喷墨打印、湿法纺丝和静电纺丝技术制备了由光滑内层、周向排列的纤维中层和随机分布的纤维外层组成的三层PLCL血管移植物（TVG）。TVG具有抗扭结性能和足够的机械性能（拉伸强度、弹性模量、缝线保留强度和爆破压力），等同于临床应用的金标准导管，即人隐静脉和人乳内动脉。TVG的分层结构对特定血管细胞表现出明显的引导作用，包括增强内皮细胞（EC）单层形成、有利于血管平滑肌细胞（VSMC）排列和伸长，以及促进成纤维细胞增殖和连接建立。我们的研究为设计聚合物合成血管移植物提供了一条新途径。
