Conducting Biomaterials for Nerve Regeneration

描述（申请人提供）：在美国，每年有超过一百万人遭受严重的周围神经损伤，每年进行20，000例手术来修复受损的周围神经。神经引导通道（NGC）是用于桥接切断的周围神经的大间隙的中空导管。目前NGC的材料有许多缺点，经常妨碍它们的使用或导致程序失败。因此，需要新的生物材料，积极促进神经再生的改进NGC的制造。 导电生物材料是令人感兴趣的，因为它们可以用于将电刺激传递到响应细胞，如成骨细胞、内皮细胞和神经元。聚吡咯（PPy）是一种无细胞毒性的导电聚合物，已被证明有利于大鼠受损周围神经的再生。由于PPy是一种半导体，它可以用于向培养的细胞提供电刺激，加速它们的生长，迁移和增殖。不幸的是，PPy是不可生物降解的，并且由PPy制成的NGC必须在愈合后从体内移除，需要第二次手术并导致额外的部位发病率。此外，PPy与大多数导电聚合物一样，是不溶和不熔的，并且具有差的机械性能。因此，很难将其加工成必要的形式。总之，这些特性限制了PPy在组织工程中的实际应用。 该项目的目标是制造一种可生物降解的PPy形式，可以从溶液中加工，并测试其作为切断神经再生支持的特性。在I期项目期间，TDA成功制备了一种基于PPy的生物材料，该材料具有导电性，可以从溶液中加工，并在体外支持神经元生长。

DESCRIPTION (provided by applicant): In the U.S. more than one million people suffer serious peripheral nerve injuries every year and 20,000 procedures are carried out annually to repair severed peripherals nerves. Nerve guidance channels (NGCs) are hollow conduits used to bridge large gaps of severed peripheral nerves. Current NGC's materials have many drawbacks that often preclude their use or cause failure of the procedure. Therefore, new biomaterials that actively promote nerve regeneration are needed for the fabrication of improved NGCs. Electrically conducting biomaterials are of interest because they can be used to deliver electrical stimulation to responsive cells like osteoblasts, endothelial cells, and neurons. Polypyrrole (PPy) is an electrically conducting polymer that is not cytotoxic and has been demonstrated to favor the regeneration of damaged peripheral nerves in rats. Because PPy is a semiconductor, it can be used to deliver electric stimuli to cultured cells, accelerating their growth, migration and proliferation. Unfortunately PPy is not biodegradable, and NGCs made of PPy must be removed from the body upon healing, requiring a second surgery and causing additional site morbidity. Moreover, PPy, like most conducting polymers, is insoluble and infusible, and has poor mechanical properties. Therefore, it is very difficult to process it into the necessary form. Together, these properties limit the practical applications of PPy in tissue engineering. The objective of this project is to make a biodegradable form of PPy that can be processed from solution, and to test its properties as a support for the regeneration of severed nerves. During the Phase I project TDA successfully prepared a PPy-based biomaterials that are electrically conducting, can be processed from solution and support well neuron growth in vitro.