Chapman Christopher A R, Wang Ling, Chen Hao, Garrison Joshua, Lein Pamela J, Seker Erkin
Department of Biomedical Engineering, University of California, Davis, Davis, CA 95616, USA.
Department of Electrical and Computer Engineering, University of California, Davis, Davis, CA 95616, USA.
Adv Funct Mater. 2017 Jan 19;27(3). doi: 10.1002/adfm.201604631. Epub 2016 Dec 12.
Nanostructured neural interface coatings have significantly enhanced recording fidelity in both implantable and in vitro devices. As such, nano-porous gold (np-Au) has shown promise as a multifunctional neural interface coating due, in part, to its ability to promote nanostructure-mediated reduction in astrocytic surface coverage while not affecting neuronal coverage. The goal of this study is to provide insight into the mechanisms by which the np-Au nanostructure drives the differential response of neurons versus astrocytes in an in vitro model. Utilizing microfabricated libraries that display varying feature sizes of np-Au, it is demonstrated that np-Au influ-ences neural cell coverage through modulating focal adhesion formation in a feature size-dependent manner. The results here show that surfaces with small (≈30 nm) features control astrocyte spreading through inhibition of focal adhesion formation, while surfaces with large (≈170 nm and greater) features control astrocyte spreading through other mechanotransduction mechanisms. This cellular response combined with lower electrical impedance of np-Au electrodes significantly enhances the fidelity and stability of electrophysiological recordings from cortical neuronglia co-cultures relative to smooth gold electrodes. Finally, by leveraging the effect of nanostructure on neuronal versus glial cell attachment, the use of laser-based nanostructure modulation is demonstrated for selectively patterning neurons with micrometer spatial resolution.
纳米结构的神经接口涂层显著提高了可植入设备和体外设备的记录保真度。因此，纳米多孔金（np-Au）已显示出作为多功能神经接口涂层的潜力，部分原因在于它能够促进纳米结构介导的星形胶质细胞表面覆盖率降低，同时不影响神经元覆盖率。本研究的目的是深入了解np-Au纳米结构在体外模型中驱动神经元与星形胶质细胞产生不同反应的机制。利用展示不同np-Au特征尺寸的微纳加工库，研究表明np-Au通过以特征尺寸依赖的方式调节粘着斑形成来影响神经细胞覆盖率。此处结果表明，具有小（≈30 nm）特征的表面通过抑制粘着斑形成来控制星形胶质细胞的铺展，而具有大（≈170 nm及更大）特征的表面则通过其他机械转导机制控制星形胶质细胞的铺展。这种细胞反应与np-Au电极较低的电阻抗相结合，相对于光滑金电极，显著提高了皮质神经元-神经胶质细胞共培养物电生理记录的保真度和稳定性。最后，通过利用纳米结构对神经元与神经胶质细胞附着的影响，展示了基于激光的纳米结构调制用于以微米空间分辨率选择性地对神经元进行图案化。
