ABSTRACT

Currently, one of the best preparation strategies for the triple-layered vascular scaffold is to imitate the three-layer structure of natural blood vessels to achieve the biofunctional characteristics of vascular transplantation. Here, we developed a combinatorial method to fabricate triple-layered vascular scaffold (TVS) by using electrospinning and coaxial 3D printing. First, Polycaprolactone-collagen (PCL-Col) was applied to prepared the inner layer of TVS by electrospinning. Second, egg white/sodium alginate (EW/SA) blend hydrogel was extruded to form hollow filaments by coaxial 3D printing and crosslinking mechanism, which enwound around the surface of the inner layer in a circumferential direction as the intermediate layer of TVS. Finally, electrospun PCL-Col nanofibers was wrapped on the surface of hydrogel layer as the outer layer of TVS. The morphological characterization and mechanical strength of the fabricated TVS were measured. Compared with natural blood vessels, results shown that ultimate tensile stress (UTS), strain to failure (STF), the estimated burst strength and the suture retention strength (SRS) of TVS were superior. Also, the fabricated TVS exhibits good hydrophilicity and excellent flexibility. Moreover, the biocompatibility of TVS was investigated through human umbilical vein endothelial cells (HUVECs), the results demonstrated that cells can successfully attach the surface of graft and maintain high viability. In summary, all of results demonstrated that this method could fabricate a novel triple-layered vascular scaffold, possessing appropriate mechanical properties and good biological properties, which has the potential to be used in tissue engineered vascular grafts applications.

摘要

当前，三层血管支架的最佳制备策略之一是模仿天然血管的三层结构，以实现血管移植的生物功能特性。在这里，我们开发了一种组合方法，通过使用静电纺丝和同轴3D打印来制造三层血管支架（TVS）。首先，将聚己内酯-胶原（PCL-Col）应用于通过静电纺丝制备TVS的内层。其次，通过同轴3D打印和交联机制将蛋清/藻酸钠（EW / SA）共混水凝胶挤出以形成空心丝，该空心丝沿圆周方向缠绕在内层表面作为TVS的中间层。最后，将电纺PCL-Col纳米纤维包裹在作为TVS外层的水凝胶层表面。测量了所制造的TVS的形态特征和机械强度。与天然血管相比，TVS的极限拉伸应力（UTS），破坏应变（STF），估计的破裂强度和缝合线保持强度（SRS）更好。而且，所制造的TVS表现出良好的亲水性和优异的柔韧性。此外，通过人脐静脉内皮细胞（HUVEC）研究了TVS的生物相容性，结果表明细胞可以成功地附着在移植物表面并保持高存活率。总而言之，所有结果均表明该方法可制备出具有适当机械性能和良好生物学特性的新型三层血管支架，