Micropatterned polypyrrole: A combination of electrical and topographical characteristics for the stimulation of cells
Micropatterned polypyrrole: A combination of electrical and topographical characteristics for the stimulation of cells
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DOI：
10.1002/adfm.200600669
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发表时间：
2007-07-09
影响因子：
19
通讯作者：
Schmidt, Christine E.
中科院分区：
文献类型：
--
作者：
Gomez, Natalia;Lee, Jae Y.;Schmidt, Christine E.
聚吡咯(PPy)等导电聚合物是神经工程中重要的生物材料，包括神经探针、神经导管、组织和神经再生支架等。这些聚合物的表面修饰除了导电性之外，还可以为神经接口引入其他有价值的特性，如地形特征和化学生物活性。在这里，报道了PPy的图案化，以创建细胞的地形线索。特别地，利用电子束光刻和电聚合技术制作了1 PM和2 PM宽的PPy微通道。对控制PPy微图案化的参数进行了系统的分析，发现微沟道深度、粗糙度和形貌高度依赖于电子束写入电流、聚合电流、PPy/掺杂浓度和聚合时间。在这种修饰材料上，培养在图案化PPy上的胚胎海马神经元极化(即定义一个轴突)更快，与培养在未修饰PPy上的细胞相比，有轴突的细胞数量增加了一倍。这些地形特征对轴突方向也有影响，但对轴突总长度没有显著影响。这是第一次研究用于生物应用的小尺寸受控PPy图案化(即小于5 PM)，这表明了不断扩展的微电子材料和技术与生物医学领域的相关性。
Electrically conducting polymers such as polypyrrole (PPy) are important biomaterials in neural engineering applications, including neural probes, nerve conduits, and scaffolds for tissue and nerve regeneration. Surface modification of these polymers can introduce other valuable characteristics for neural interfacing in addition to electrical conductivity, such as topographical features and chemical bioactivity. Here, the patterning of PPy to create topographical cues for cells is reported. In particular, 1 and 2 pm wide PPy microchannels are fabricated using electron-beam (e-beam) lithography and electropolymerization. A systematic analysis of parameters controlling PPy micropatterning is performed, and finds that microchannel depth, roughness, and morphology are highly dependent on the e-beam writing current, polymerization current, PPy/dopant concentrations, and the polymerization time. Embryonic hippocampal neurons cultured on patterned PPy polarize (i.e., defined an axon) faster on this modified material, with a twofold increase in the number of cells with axons compared to cells cultured on unmodified PPy. These topographical features also have an effect on axon orientation but do not have a significant effect on overall axon length. This is the first investigation that studies controlled PPy patterning with small dimensions (i.e., less than 5 pm) for biological applications, which demonstrates the relevance of expanding microelectronic materials and techniques to the biomedical field.