The effect of high outflow permeability in asymmetric poly(DL-lactic acid-co-glycolic acid) conduits for peripheral nerve regeneration
The effect of high outflow permeability in asymmetric poly(DL-lactic acid-co-glycolic acid) conduits for peripheral nerve regeneration
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DOI：
10.1016/j.biomaterials.2005.07.003
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发表时间：
2006-10-01
期刊：
影响因子：
14
通讯作者：
Hsu, SH
中科院分区：
文献类型：
--
作者：
Chang, CJ;Hsu, SH
本研究试图利用不对称聚（DL-乳酸-乙醇酸）（PLGA）神经导管的高流出率来加速周围神经再生。采用浸没沉淀法制备了单体比例为85/15的不对称PLGA神经导管作为可能的材料。在本研究中，将心轴浸入 20%（wt/wt）的 PLGA/1,4-二恶烷溶液中，并在非溶剂浴中沉淀，然后冷冻干燥。使用不同浓度的异丙醇（95%、40%和20%）作为沉淀浴，其中很容易形成非不对称（95%）和不对称（40%和20%）导管。外层由大孔隙组成，内层由相互连接的微孔组成的不对称神经导管具有流出速率大于流入速率的特征。将不对称导管植入大鼠右侧10毫米坐骨神经缺损处。自体移植物、硅胶和非对称 PLGA 导管作为对照组和对比组。手术后4周和6周收获所有组的植入移植物标本用于组织学分析。不对称PLGA导管在整个再生过程中保持稳定的支撑结构并抑制外源细胞侵袭。在第 4 周和第 6 周时，与硅胶组和非不对称组相比，不对称 PLGA 导管在植入移植物的中导管和远端神经部位具有统计上更多的再生轴突数量。有趣的是，在轴突数量方面，4 周时不对称组的结果优于非不对称组 6 周时的结果。根据渗透性结果，导管壁的不对称结构似乎增强了早期内部发炎伤口废物引流堵塞的清除，这可能提高了周围神经再生的功效。这种不对称结构将来可以充分用作周围神经再生的最佳神经导管。 (c) 2005 Elsevier Ltd. 保留所有权利。
This study attempted to accelerate the peripheral nerve regeneration, using the high Outflow rate of asymmetric poly(DL-lactic acid-co-glycolic acid) (PLGA) nerve conduits. Asymmetric PLGA nerve conduits of monomer ratio 85/15 were prepared by immersion-precipitation method to serve as possible materials. In this study, mandrels were immersed into a 20% (wt/wt) of PLGA/1,4-dioxane solution and precipitated in a non-solvent bath followed by freeze-drying. Different concentrations of isopropyl alcohol (95%, 40% and 20%) were used as precipitation baths where non-asymmetric (95%) and asymmetric (40% and 20%) conduits could easily form. The asymmetric nerve conduits that consisted of macrovoids on the outer layer, and interconnected micropores in the inner sublayer, possessed characters of larger outflow rate than inflow rate. The asymmetric conduits were implanted to 10 mm right sciatic nerve defects in rats. Autografts, silicone and non-asymmetric PLGA conduits were performed as the control and the contrast groups. Implanted graft specimens of all groups were harvested for histological analysis at 4 and 6 weeks following Surgery. The asymmetric PLGA conduits maintained a stable supporting structure and inhibited exogenous cells invasion during entire regeneration process. Asymmetric PLGA conduits were found to have statistically greater number of regenerated axons at the midconduit and distal nerve site of implanted grafts, as compared to the silicone and non-asymmetric groups at 4 and 6 weeks. Of interest was that the results of 4 weeks in asymmetric groups were better than the non-asymmetric groups at 6 weeks in number of axons. According to the results of permeability, the asymmetric structure in the conduit wall seemed to enhance the removal of the blockage of the waste drain from the inner inflamed wound in the early stage, which may have improved the efficacy of the peripheral nerve regeneration. The asymmetric structure could be adequately employed in the future as optimal nerve conduits in peripheral nerve regeneration. (c) 2005 Elsevier Ltd. All rights reserved.