State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai 201620, China.
ACS Appl Mater Interfaces. 2013 Mar;5(6):2220-6. doi: 10.1021/am400099p. Epub 2013 Mar 18.
We herein proved that the two commonly used antithrombotic methods, heparin loading and pre-endothelialization could both greatly enhance the patency rate of a small-diameter graft in a canine model. Tubular grafts having an inner diameter of 4 mm were prepared by electrospinning poly(l-lactide-co-ε-caprolactone) (P(LLA-CL)) and heparin through a coaxial electrospinning technique. Seventy-two percent of heparin was found to be released sustainably from the graft within 14 days. To prepare the pre-endothelialized grafts, we seeded endothelial cells isolated from the femoral artery and cultured then dynamically on the lumen until a cell monolayer was formed. Digital subtraction angiography (DSA) and color Doppler flow imaging (CDFI) were used to monitor the patency without sacrificing the animals. Histological analyses revealed that following the direction of blood flow, a cell monolayer was formed at the proximal end of the heparin-loaded grafts, but such a monolayer could be found in the middle or distal region of the grafts. In contrast, the whole luminal surface of the pre-endothelialized graft was covered by a cell monolayer, suggesting the in vivo survival of the preseeded cells. This demonstrated that heparin was a comparatively simple method to achieve good patency, but the pre-endothelialization had better mechanical properties and cellular compatibility.
我们在此证明，两种常用的抗血栓形成方法，肝素加载和预内皮化，都可以极大地提高犬模型中小直径移植物的通畅率。通过同轴静电纺丝技术，用聚（L-丙交酯-共-ε-己内酯）（P（LLA-CL））和肝素制备内径为 4mm 的管状移植物。在 14 天内，有 72%的肝素从移植物中持续释放。为了制备预内皮化移植物，我们从股动脉分离内皮细胞并进行培养，然后在管腔中动态培养，直到形成细胞单层。数字减影血管造影（DSA）和彩色多普勒血流成像（CDFI）用于监测不牺牲动物的通畅性。组织学分析表明，在血流方向的作用下，肝素负载移植物的近端形成了一层细胞单层，但在移植物的中部或远端区域可以发现这种单层。相比之下，预内皮化移植物的整个管腔表面都被细胞单层覆盖，表明预种植细胞在体内存活。这表明肝素是一种实现良好通畅率的相对简单的方法，但预内皮化具有更好的机械性能和细胞相容性。
