Background Small-diameter vascular grafts have become the focus of attention in tissue engineering. Thrombosis and aneurysmal dilatation are the two major complications of the loss of vascular access after surgery. Therefore, we focused on fabricating 3D printed electrospun vascular grafts loaded with tetramethylpyrazine (TMP) to overcome these limitations. Methods Based on electrospinning and 3D printing, 3D-printed electrospun vascular grafts loaded with TMP were fabricated. The inner layer of the graft was composed of electrospun poly(L-lactic-co-caprolactone) (PLCL) nanofibers and the outer layer consisted of 3D printed polycaprolactone (PCL) microfibers. The characterization and mechanical properties were tested. The blood compatibility and in vitro cytocompatibility of the grafts were also evaluated. Additionally, rat abdominal aortas were replaced with these 3D-printed electrospun grafts to evaluate their biosafety. Results Mechanical tests demonstrated that the addition of PCL microfibers could improve the mechanical properties. In vitro experimental data proved that the introduction of TMP effectively inhibited platelet adhesion. Afterwards, rat abdominal aorta was replaced with 3D-printed electrospun grafts. The 3D-printed electrospun graft loaded with TMP showed good biocompatibility and mechanical strength within 6 months and maintained substantial patency without the occurrence of acute thrombosis. Moreover, no obvious aneurysmal dilatation was observed. Conclusions The study demonstrated that 3D-printed electrospun vascular grafts loaded with TMP may have the potential for injured vascular healing.

中文翻译：

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开发负载四甲基吡嗪的 3D 打印电纺血管移植物，用于减少血栓形成并抑制动脉瘤扩张。


背景小直径血管移植物已成为组织工程领域关注的焦点。血栓形成和动脉瘤扩张是手术后失去血管通路的两个主要并发症。因此，我们专注于制造负载四甲基吡嗪 (TMP) 的 3D 打印电纺血管移植物，以克服这些限制。方法基于静电纺丝和3D打印技术，制备负载TMP的3D打印静电纺血管移植物。移植物的内层由电纺聚（L-乳酸-己内酯）（PLCL）纳米纤维组成，外层由3D打印的聚己内酯（PCL）微纤维组成。测试了表征和机械性能。还评估了移植物的血液相容性和体外细胞相容性。此外，大鼠腹主动脉被这些 3D 打印的电纺移植物取代，以评估其生物安全性。结果力学测试表明，PCL微纤维的添加可以提高力学性能。体外实验数据证明，TMP的引入有效抑制血小板粘附。随后，大鼠腹主动脉被 3D 打印的电纺移植物取代。负载TMP的3D打印电纺移植物在6个月内表现出良好的生物相容性和机械强度，并保持基本通畅，未发生急性血栓形成。此外，未观察到明显的动脉瘤扩张。结论 该研究表明，负载 TMP 的 3D 打印电纺血管移植物可能具有修复受损血管的潜力。