用高度取向石墨烯/聚乳酸(Gr/PLLA)复合超细纤维构建神经导管

Highly Aligned Ultrafine Fibers of Graphene/Poly(L-lactic acid)(Gr/PLLA)Composite for the Construction of Nerve Conduit

制备了一种高度取向的石墨烯(Gr)/聚乳酸(PLLA)复合超细纤维,并构建了神经导管,研究了Gr/PLLA促进神经细胞生长与分化的协同诱导作用.研究结果表明,Gr/PLLA具有较好的纤维形貌与取向度;Gr的引入提高了纤维的热性能及力学性能;Gr加入量(≤1%)的增加及纤维取向度的提高使雪旺细胞(SCs)的黏附数量及伸展比例均呈增加趋势;Gr/PLLA纤维可促进SCs的增殖,雪旺细胞在96 h时达到最佳生长状态,表明Gr/PLLA纤维具有较好的细胞相容性.基于细胞形貌及轴突数量统计发现,Gr/PLLA纤维也能促进大鼠肾上腺嗜铬细胞瘤(PC12细胞)的神经分化.直径为2 mm的Gr/PLLA纤维导管具有较好的纤维取向度和抗压能力,能促进细胞沿管轴方向取向生长.

Highly aligned ultrafine fibers of graphene/poly（ L-lactic acid）（ Gr/PLLA） composite were prepared for studying the synergistic effect of fiber orientation degree and Gr incorporation on nerve cell growth and differentiation,from which nerve conduits by reeling-heating the aligned Gr/PLLA fibers were fabricated for potential neural tissue engineering applications. The results showed that the Gr/PLLA fibers made by stable jet electrospinning（ SJES） had higher degree of fiber alignment. Incorporation of Gr improved the thermal and mechanical properties of the PLLA fibers. Increasing the Gr content and fiber orientation degree gave rise to increased adhesion number and elongation percentage of the Schwann cells（ SCs）. All the fiber scaffolds could promote SCs to proliferate well and cells growth reached the best state at 96 h,indicating appropriate cytocompatibility of the Gr/PLLA fibers. In addition,it was found the aligned Gr/PLLA fibers also promoted the neural differentiation of PC12 cells. The nerve conduits with inner diameter of 2 mm made of Gr/PLLA fibers showed good axial fiber orientation degree and pressure-resistance ability,and could promote cell growth directionally.