Goodfriend Amy C, Welch Tré R, Barker Greg, Ginther Richard, Riegel Matthew S, Reddy Surendranath Veeram, Wang Jian, Nugent Alan, Forbess Joseph
Department of Pediatric Cardiovascular and Thoracic Surgery, University of Texas Southwestern Medical Center, Dallas, Texas, 75390.
J Biomed Mater Res A. 2015 May;103(5):1761-70. doi: 10.1002/jbm.a.35313. Epub 2014 Sep 16.
A novel double opposed helical poly-l-lactic acid (PLLA) bioresorbable stent has been designed for use in pediatrics. The aim was to test the PLLA stent biocompatibility. The PLLA stent was immersed into whole pig's blood in a closed loop circuit then fibrin and platelet association was assessed via enzyme-linked immunosorbent assay. D-Dimer was valued at 0.2 ± 0.002 ng/mL and P-selectin 0.43 ± 00.01 ng/mL indicating limited association of fibrin and platelets on the stent. To improve biocompatibility by targeting inflammatory cells, dexamethasone was incorporated on PLLA fibers with two coating methods. Both coatings were poly(l-lactide-co-glycolide) acid (PLGA) but one was made porous with sucrose while the other remained nonporous. There was no change in mechanical properties of the fiber with either coating of PLGA polymer. The total amount of dexamethasone released was then determined for each coating. The cumulative drug release for the porous fiber was significantly higher (∼100%) over 8 weeks than the nonporous fiber (40%). Surface examination of the fiber with scanning electron microscopy showed more surface microfracturing in coatings that contain pores. The biocompatibility of this novel stent was demonstrated. Mechanical properties of the fiber were not altered by coating with PLGA polymer. Anti-inflammatory drug release was optimized using a porous PLGA polymer.
一种新型的双对置螺旋聚左旋乳酸（PLLA）生物可吸收支架已被设计用于儿科。目的是测试PLLA支架的生物相容性。将PLLA支架浸入闭环回路中的全猪血中，然后通过酶联免疫吸附测定法评估纤维蛋白和血小板的结合情况。D - 二聚体的值为0.2±0.002 ng/mL，P - 选择素为0.43±0.01 ng/mL，表明支架上纤维蛋白和血小板的结合有限。为了通过靶向炎症细胞来提高生物相容性，采用两种包被方法将地塞米松掺入PLLA纤维中。两种包被材料均为聚（左旋丙交酯 - 共 - 乙交酯）酸（PLGA），但一种用蔗糖制成多孔结构，另一种保持无孔结构。用PLGA聚合物进行任何一种包被时，纤维的机械性能均无变化。然后测定每种包被材料地塞米松的释放总量。在8周内，多孔纤维的药物累积释放量（约100%）显著高于无孔纤维（40%）。用扫描电子显微镜对纤维进行表面检查显示，含孔包被材料的表面微裂纹更多。这种新型支架的生物相容性得到了证实。用PLGA聚合物包被不会改变纤维的机械性能。使用多孔PLGA聚合物优化了抗炎药物的释放。
