Huang Yi-Cheng, Huang Yi-You, Huang Chun-Chieh, Liu Hwa-Chang
Institute of Biomedical Engineering, College of Engineering, College of Medicine, National Taiwan University, Taipei, Republic of China.
J Biomed Mater Res B Appl Biomater. 2005 Jul;74(1):659-64. doi: 10.1002/jbm.b.30267.
We have developed a method for nerve tissue regeneration using longitudinally oriented channels within biodegradable polymers created by a combined lyophilizing and wire-heating process. This type of cell-adhesive scaffold provides increased area to support and guide extending axons subsequent to nerve injury. Utilizing Ni-Cr wires as mandrels to create channels in scaffold increased safety, effectiveness, and reproducibility. The scaffolds tested were made from different biodegradable polymers, chitosan and poly(D,L-lactide-co-glycolide) (PLGA), because of their availability, ease of processing, low inflammatory response, and approval by the FDA. According to our experimental results, the high permeability and the characteristic porous structure of chitosan proved to be a better material for nerve guidance than PLGA. The scanning electron micrographs revealed that the scaffolds were consistent along the longitudinal axis with channels being distributed evenly throughout the scaffolds. There was no evidence to suggest merging or splitting of individual channels. The diameter of the channels was about 100 mum, similar to the 115 micromameter of the Ni-Cr wire. Regulating the size and quantity of the Ni-Cr wires allow us to control the number and the diameter of the channels. Furthermore, the neutralizing processes significantly influenced the porous structure of chitosan scaffolds. Using weak base (NaHCO(3) 1M) to neutralize chitosan scaffolds made the porous structure more uniform. The innovative method of using Ni-Cr wires as mandrels could be easily tailored to other polymer and solvent systems. The high permeability and the characteristic porous structure of chitosan made it a superior material for nerve tissue engineering. These scaffolds could be useful for guiding regeneration of the peripheral nerve or spinal cord after a transection injury.
我们开发了一种用于神经组织再生的方法，该方法利用通过冻干和线加热相结合的过程在可生物降解聚合物中形成的纵向通道。这种类型的细胞粘附支架为神经损伤后支持和引导轴突延伸提供了更大的面积。利用镍铬丝作为芯轴在支架中创建通道提高了安全性、有效性和可重复性。所测试的支架由不同的可生物降解聚合物壳聚糖和聚（D，L-丙交酯-共-乙交酯）（PLGA）制成，因为它们易于获得、易于加工、炎症反应低且已获得美国食品药品监督管理局（FDA）的批准。根据我们的实验结果，壳聚糖的高渗透性和特有的多孔结构被证明是比PLGA更好的神经引导材料。扫描电子显微镜照片显示，支架沿纵轴一致，通道均匀分布在整个支架中。没有证据表明单个通道会合并或分裂。通道的直径约为100微米，与镍铬丝的115微米相似。调节镍铬丝的尺寸和数量使我们能够控制通道的数量和直径。此外，中和过程显著影响壳聚糖支架的多孔结构。使用弱碱（1M碳酸氢钠）中和壳聚糖支架使多孔结构更加均匀。使用镍铬丝作为芯轴的创新方法可以很容易地应用于其他聚合物和溶剂体系。壳聚糖的高渗透性和特有的多孔结构使其成为神经组织工程的优质材料。这些支架可用于引导横断损伤后周围神经或脊髓的再生。
