IMPROVED NERVE REGENERATION THROUGH PIEZOELECTRIC VINYLIDENEFLUORIDE-TRIFLUOROETHYLENE COPOLYMER GUIDANCE CHANNELS
IMPROVED NERVE REGENERATION THROUGH PIEZOELECTRIC VINYLIDENEFLUORIDE-TRIFLUOROETHYLENE COPOLYMER GUIDANCE CHANNELS
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DOI：
10.1016/0142-9612(91)90029-a
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发表时间：
1991-10-01
期刊：
影响因子：
14
通讯作者：
AEBISCHER, P
中科院分区：
文献类型：
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作者：
FINE, EG;VALENTINI, RF;AEBISCHER, P
机械应变时产生电荷的压电材料可以用来刺激神经损伤后的轴突再生。管状神经引导通道由偏氟乙烯-三氟乙烯共聚物通过熔融挤出工艺挤出而成。与偏氟乙烯均聚物不同，该共聚物不需要机械拉伸来获得含有偶极的晶体结构，从而能够制造复杂的压电器件。选定的管子在高压电晕极化装置中进行压电处理。用差示扫描量热法研究了极化引起的晶体结构变化。与未极化样品相比，极化样品在居里温度下表现出尖锐的吸热峰和较大的转变热，表明晶体的有序性和尺寸增加。利用与电荷放大器和示波器相连接的激光监测偏转系统来表征极化管的压电输出。极化管对轻微的机械变形产生了显著的电压。电输出的大小与极化极性无关。未极化的管子没有电输出。用正极、负极和未极化的偏氟乙烯-三氟乙烯共聚物管修复成年大鼠坐骨神经横断后10 mm的缺损区。植入4wk后，在正极通道再生的神经的有髓轴突数量明显多于在无极通道再生的神经。负极化通道含有中等数量的有髓轴突。我们的结论是，与化学上相同的未极化的管相比，具有压电活性的偏氟乙烯-三氟乙烯共聚物管显著地促进了神经再生，并且用于制备压电材料的电晕极化过程的极性可能在确定生物反应中发挥作用。
Piezoelectric materials generating electrical charges in response to mechanical strain may be used to stimulate axonal regeneration following nerve injury. Tubular nerve guidance channels were extruded from a vinylidenefluoride-trifluoroethylene copolymer using a melt-extrusion process. Unlike vinylidenefluoride homopolymer, the copolymer does not need mechanical stretching to achieve a dipole-containing crystal structure, enabling the fabrication of complex piezoelectric devices. Selected tubes were rendered piezoelectric in a high voltage corona poling apparatus. Crystal structure changes induced by poling were evaluated with differential scanning calorimetry. In contrast to unpoled samples, poled ones displayed a sharp endothermic peak and a greater heat of transition at the Curie temperature, indicative of an increase in crystal order and size. The piezoelectric output of poled tubes was characterized using a laser-monitored deflection system interfaced with a charge amplifier and oscilloscope. Poled tubes generated significant voltages in response to slight mechanical deformations. The magnitude of electrical output was independent of the poling polarity. Unpoled tubes showed no electrical output. Positive, negative and unpoled vinylidenefluoride-trifluoroethylene copolymer tubes were used to repair a 10 mm gap in transected sciatic nerves of adult rats. Nerves regenerated in positively poled channels had a significantly greater number of myelinated axons than those regenerated in unpoled channels 4 wk post-implantation. Negatively poled channels contained an intermediate number of myelinated axons. We concluded that piezoelectrically active vinylidenefluoride-trifluoroethylene copolymer tubes significantly enhance nerve regeneration as compared to chemically identical, unpoled tubes and that the polarity of the corona poling procedure used to fabricate piezoelectric materials may play a role in determining biological responses.