Avci-Adali Meltem, Grözinger Gerd, Cabane Vincent, Schreve Michiel, Wendel Hans Peter
Department of Thoracic and Cardiovascular Surgery, University Hospital Tuebingen, Calwerstraße 7/1, 72076 Tuebingen, Germany.
Department of Diagnostic and Interventional Radiology, University Hospital Tuebingen, Hoppe-Seyler-Strasse 3, 72076 Tuebingen, Germany.
Bioengineering (Basel). 2023 Mar 26;10(4):411. doi: 10.3390/bioengineering10040411.
Polytetrafluoroethylene (PTFE) is a commonly used biomaterial for the manufacturing of vascular grafts and several strategies, such as coatings, have been explored to improve the hemocompatibility of small-diameter prostheses. In this study, the hemocompatibility properties of novel stent grafts covered with electrospun PTFE (LimFlow Gen-1 and LimFlow Gen-2) were compared with uncoated and heparin-coated PTFE grafts (Gore Viabahn) using fresh human blood in a Chandler closed-loop system. After 60 min of incubation, the blood samples were examined hematologically and activation of coagulation, platelets, and the complement system were analyzed. In addition, the adsorbed fibrinogen on the stent grafts was measured and the thrombogenicity was assessed by SEM. Significantly lower adsorption of fibrinogen was measured on the surface of heparin-coated Viabahn than on the surface of the uncoated Viabahn. Furthermore, LimFlow Gen-1 stent grafts showed lower fibrinogen adsorption than the uncoated Viabahn, and the LimFlow Gen-2 stent grafts showed comparable fibrinogen adsorption as the heparin-coated Viabahn. SEM analysis revealed no sign of thrombus formation on any of the stent surfaces. LimFlow Gen-2 stent grafts covered with electrospun PTFE exhibited bioactive characteristics and revealed improved hemocompatibility in terms of reduced adhesion of fibrinogen, activation of platelets, and coagulation (assessed by β-TG and TAT levels) similar to heparin-coated ePTFE prostheses. Thus, this study demonstrated improved hemocompatibility of electrospun PTFE. The next step is to conduct in vivo studies to confirm whether electrospinning-induced changes to the PTFE surface can reduce the risk of thrombus formation and provide clinical benefits.
聚四氟乙烯（PTFE）是一种常用于制造血管移植物的生物材料，人们已经探索了多种策略，如涂层等，以改善小口径假体的血液相容性。在本研究中，使用新鲜人血在钱德勒闭环系统中，将新型电纺PTFE覆盖的支架移植物（LimFlow Gen-1和LimFlow Gen-2）的血液相容性特性与未涂层和肝素涂层的PTFE移植物（Gore Viabahn）进行了比较。孵育60分钟后，对血样进行血液学检查，并分析凝血、血小板和补体系统的激活情况。此外，测量了支架移植物上吸附的纤维蛋白原，并通过扫描电子显微镜评估血栓形成倾向。结果显示，肝素涂层的Viabahn表面纤维蛋白原的吸附量明显低于未涂层的Viabahn表面。此外，LimFlow Gen-1支架移植物的纤维蛋白原吸附量低于未涂层的Viabahn，而LimFlow Gen-2支架移植物的纤维蛋白原吸附量与肝素涂层的Viabahn相当。扫描电子显微镜分析显示，任何支架表面均未出现血栓形成迹象。电纺PTFE覆盖的LimFlow Gen-2支架移植物表现出生物活性特征，在减少纤维蛋白原黏附、血小板激活和凝血方面（通过β-血小板球蛋白和凝血酶-抗凝血酶复合物水平评估）显示出改善的血液相容性，类似于肝素涂层的ePTFE假体。因此，本研究证明了电纺PTFE的血液相容性得到改善。下一步是进行体内研究，以确认电纺对PTFE表面的改变是否可以降低血栓形成风险并带来临床益处。
