新型编织型神经导管的制备及其性能

背景：以往的单层编织型神经导管缺少细胞黏附及神经生长所需的支架结构，不利于神经向远断端生长。 目的：通过改进纺织技术，用聚乙丙交酯可降解生物医用纤维生产出3种新型编织型神经导管，并从导管的力学性能、结构特点、孔隙率、体外降解性能方面与单层神经导管进行比较。 设计、时间及地点：对比观察实验，于2007-11/2008-09在东华大学生物医用纺织品研究中心完成。 材料：应用聚乙丙交酯纱线制备单层编织型神经导管；由聚乙丙交酯纱线编织外层管壁，分别用甲壳素无纺布、聚乙丙交酯纱线为内层管壁，制备黏合平行纱编织型神经导管、蓬松平行纱编织型神经导管和甲壳素编织型神经导管。 方法：比重瓶法测量4种神经导管的孔隙率；微机控制万能材料试验机上拉抻至导管10%破坏测试拉伸性能；扭转强力测试仪上扭转90°测试扭转性能；神经导管浸入磷酸盐缓冲液中，置于培养箱定期取出，冷冻干燥后称质量测量其降解性能；径向压缩仪上进行径向压缩实验。 主要观察指标：神经导管的孔隙率，抗变形能力。 结果：黏合平行纱编织型神经导管内层为黏合聚乙丙交酯平行纱，截面特征为管中管结构；蓬松平行纱编织型神经导管内层为蓬松聚乙丙交酯平行纱，截面特征为内层支架结构；甲壳素编织型神经导管内层为甲壳素无纺布，截面特征为管中管结构。4种神经导管的孔隙率相当，都在80%左右，均能满足神经导管中细胞生长的要求；新型编织型神经导管的拉伸性能、抗扭转能力较单层导管有一定的提高，在降解过程中，新型编织型神经导管的压缩性能损失率较小。 结论：新型编织神经导管的双层结构，使得外管壁具有较好的通透性。与原有的单层神经导管比较，有较好的力学性能。

Fabrication and performance of new-type braided nerve conduits

BACKGROUND: Previous monolayer braided nerve conduits lack the scaffold structure for cell adhesion and nerve growth, which are not beneficial to the growth of the nerve towards the distal end. OBJECTIVE: By improving the textile technology, to produce three kinds of new-type braided nerve conduits with poly(glycolide-co-L-lactide)s (PLGA) biodegradable fibers, and to compare mechanical properties, structural characteristics, porosities and in vitro degradation properties between the new-type braided nerve conduit and monolayer nerve conduit. DESIGN, TIME AND SETTING: A control observational experiment was performed in the Biomedical Research Center of Donghua University from November 2007 to September 2008. MATERIALS: Monolayer braided nerve conduits were prepared by PLGA Yarns. Agglutinate parallel yarn braided nerve conduits, fluffy parallel yarn braided nerve conduits and chitin braided nerve conduits were prepared. Their external wells were braided by PLGA yarns, and internal wells were braided by PLGA yarns and chitin nonwoven fabric, respectively. METHODS: The porosities of the four kinds of nerve conduits were measured by using the pycnometer method. Their tensile properties were detected by a microcomputer controlled electrical universal testing machine when the conduits strained to 10% damage. Their torsional properties were detected by a torsion testing machine when the conduits twisted 90 degree. The nerve conduits were immersed in PBS liquor, placed into the in incubators. After freeze-drying for a week, the mass of nerve conduits was weighed and degradation properties were measured. The diameter-compression test was performed by YG061 compression instrument. MAIN OUTCOME MEASURES: The porosities and anti-deformation capacities of the four kinds of nerve conduits. RESULTS: The internal layer of agglutinate parallel yarn braided nerve conduit was agglutinate PLGA parallel yarns, and the section feature was pipe-in-pipe structure. The internal layer of fluffy parallel yarn braided nerve conduits was fluffy PLGA parallel yarns, and the section feature was bracket structure. The internal layer of chitin braided nerve conduits was chitin nonwoven fabric, and the section feature was pipe-in-pipe structure. There was no significant difference in porosities among the four kinds of nerve conduits, and all of them were approximately 80%. All kinds of the nerve conduits could meet the requirement of cells growth. The tensile properties and anti torsional properties of the three kinds of novel braided nerve conduits were better than those of the monolayer braided nerve conduits, and the loss ratio of compressive property of the novel braided nerve conduits was less than that of the monolayer braided nerve conduit in course of degradation. CONCLUSION: New-type braided nerve conduits have a two-layer structure, which makes the external well has good permeability. Compared with monolayer braided nerve conduit, they have better mechanical properties.