Department of Chemical Engineering, The University of Texas at Austin, 1 University Station, MC C0400, Austin, TX 78712, USA.
Department of Biomedical Engineering, The University of Texas at Austin, 1 University Station, MC C0800, Austin, TX 78712, USA.
Acta Biomater. 2014 Jun;10(6):2423-33. doi: 10.1016/j.actbio.2014.01.030. Epub 2014 Feb 8.
Current injury models suggest that Schwann cell (SC) migration and guidance are necessary for successful regeneration and synaptic reconnection after peripheral nerve injury. The ability of conducting polymers such as polypyrrole (PPy) to exhibit chemical, contact and electrical stimuli for cells has led to much interest in their use for neural conduits. Despite this interest, there has been very little research on the effect that electrical stimulation (ES) using PPy has on SC behavior. Here we investigate the mechanism by which SCs interact with PPy in the presence of an electric field. Additionally, we explored the effect that the adsorption of different serum proteins on PPy upon the application of an electric field has on SC migration. The results indicate an increase in average displacement of the SC with ES, resulting in a net anodic migration. Moreover, indirect effects of protein adsorption due to the oxidation of the film upon the application of ES were shown to have a larger effect on migration speed than on migration directionality. These results suggest that SC migration speed is governed by an integrin- or receptor-mediated mechanism, whereas SC migration directionality is governed by electrically mediated phenomena. These data will prove invaluable in optimizing conducting polymers for their different biomedical applications such as nerve repair.
目前的损伤模型表明，施万细胞（Schwann cell，SC）的迁移和导向对于周围神经损伤后成功的再生和突触再连接是必要的。导电聚合物如聚吡咯（polypyrrole，PPy）能够对细胞表现出化学、接触和电刺激，这引起了人们对其作为神经导管的应用的极大兴趣。尽管有这种兴趣，但关于使用 PPy 进行电刺激（electrical stimulation，ES）对 SC 行为的影响的研究却很少。在这里，我们研究了 SC 在电场存在下与 PPy 相互作用的机制。此外，我们还探讨了在施加电场时不同血清蛋白在 PPy 上的吸附对 SC 迁移的影响。结果表明，随着 ES 的施加，SC 的平均位移增加，导致净阳极迁移。此外，由于 ES 施加时薄膜的氧化，间接的蛋白质吸附作用对迁移速度的影响大于对迁移方向性的影响。这些结果表明，SC 的迁移速度由整合素或受体介导的机制控制，而 SC 的迁移方向性则由电介导的现象控制。这些数据将在优化导电聚合物用于神经修复等不同的生物医学应用方面提供非常有价值的信息。
