基于多因子复合导电丝膜的神经轴突导向生长及其延伸中的协同作用机理

导电性神经修复材料如何促进神经轴突的生长是当前的挑战之一。本项目首先用位聚合技术在聚乳酸-胶原复合平行丝表面包覆聚谷氨酸(PGlu)掺杂的聚吡咯(PPy)导电层；再采用多肽缩合技术在PGlu分子链上结合神经生长因子(NGF)、神经导向因子(Netrin3)而使之带正电荷；然后用层-层包覆(LBL)技术在其表面分别静电组装上精胺(负电荷)和GSK-3β酶、Rho-GTP蛋白(正电荷)，并在微电场作用下研究其结合四种蛋白的控制释放。将其与PC12或大鼠神经海马等细胞共培养，并将用全自动细胞膜片钳与原子力显微技术结合，系统地研究这种复合丝层的组装结构、电导性、微电场作用等因素对神经轴突的导向生长的影响，以及这些因素对轴突延伸的协同作用过程。最后用数字仿真技术构建这种复合材料与神经轴突延伸的多元相关数学模型，提出其促进神经轴突生长的协同作用机理。这将为开发临床用神经损伤修复材料打下理论基础。

How the conductive neural regeneration materials improving the directional-growth of neuraxon has remained a challenge. In this project, the conductive poly(glutamic acid)-doped polypyrole layer can be formed on the surface of the composite fibers of poly(latic acid) and collagen via in-situ polymerization. Then neural growth factor (NGF) and axon guidance factor (Netrin3) with positive charges would be conjugated onto PGlu chains through peptide condensation technique, on which then the spermine with negative charges and GSK-3β enzyme/RHo-GTP protein with positive charges could be assemblied by layer-by-layer technique,respectively. Furthermore, four proteins-release from the assemblied composite films will controlled by micro-electrical field. Through co-culture of neural cells (PC12 or rat hippocampal cells) with the composite film, the effects of their assemblied structure, electrically-conducting, micro electrical field on the guidance growth of neuraxon and the coordinated process of neural directional elongation will be systematically studied via the combination techniche of AFM and automated cell patch-clamp. Finally, a digital model of the multiariable relation between the composite neural material and axon elongation could be fibricated through a simulation technology, and coordinated mechanism of this material improving the axon elongation will be proposed.