製備電活性聚脲/奈米碳管複合材料偵測維生素C及電活性高分子基材對於神經幹細胞之應用探討

Preparation and application of electroactive polyurea/carbon nanotube composites for detection of ascorbic acid and electroactive polymer for neural stem cell growth

葉律真(Lu-Chen Yeh)

指導教授 ： 葉瑞銘

中原大學/理學院/化學研究所/博士(2014年)

https://doi.org/10.6840/cycu201400464

摘要

本研究以氧化偶合法合成主鏈上具有苯胺五聚體之電活性聚脲，以FTIR、Mass和NMR做苯胺寡聚體結構上之鑑定，利用UV-vis即時監控加入氧化劑後的電活性聚脲之氧化情形，CV量測其電活性，並將電活性聚脲首次應用於感測器之電極表面修飾材料，偵測維生素C，可得偵測極限為6.1μM；此外為使電活性聚脲具有較高之導電特性，降低在感測器上之偵測極限，本文使用Friedel-Crafts acylation reaction之方式改質奈米碳管，使碳管表面帶有胺基官能基，並利用氧化偶合反應合成電活性聚脲/奈米碳管複合材料，經由實驗結果得知，加入奈米碳管後，偵測極限可降低至3.5μM。
另一部分研究，以氧化聚合法製備一系列電活性高分子:聚苯胺之衍生物-聚鄰甲氧基苯胺(POMA)與其奈米碳管複合材料和磺酸化聚苯胺。首先在實驗室先前研究已經證實POMA具有生物相容性，並藉由靜電紡絲技術製備三維生物支架，探討其作為神經幹細胞之貼附、增生與分化之成效。結果顯示，POMA可提供神經幹細胞良好之生長環境，且在加入分化藥劑後，細胞傾向分化為神經元與星狀膠細胞，且有74%的細胞具有電感性鈣離子通道之功能性；而為使三維支架基材提高導電度，選擇添加入胺基化奈米碳管，提升其在POMA間之分散性，並嘗試施加電壓刺激，研究結果顯示，此複合材料仍須經由酸摻雜，才可使施加之電壓導通；最後合成磺酸化聚苯胺，以UV-vis和CV證實此高分子具有化學氧化與電活性，利用其自身摻雜特性，以此高分子為基材自製電刺激裝置，以體外電刺激方式促進神經幹細胞分化之能力，並將此材料應用於組織工程上。

關鍵字

電活性高分子；感測器；神經幹細胞

並列摘要

First, the electrochemical oxidation of ascorbic acid (vitamin C, AA) on the surface of carbon paste electrode (CPE) modified with electroactive polyurea (EPU) was studied by using cyclic voltammetry in this studies. EPU, with aniline-pentamer-based in the main chain, was synthesized from oligoaniline and p-phenylenediamine by oxidative coupling polymerization. The well-defined molecular structure of the oligoaniline was confirmed by FTIR, Mass, and 1H NMR spectroscopy. The in situ chemical oxidation of the reduced form of soluble, EPU in N-methyl-2-pyrrolidone was monitored by UV–visible (UV-vis) absorption spectra. Moreover, the electroactivity of the EPU was evaluated by performing electrochemical cyclic voltammetry (CV) studies. On the other hand, we also prepared amino-functionalized multiwall carbon nanotube/electroactive polyurea (AF-MWCNT/EPU) by oxidative coupling polymerization. We utilized carbon paste mixed with EPU or AF-MWCNT/EPU as an EPU carbon paste electrode or AF-MWCNT/EPU carbon paste electrode (EPU CPE or AF-MWCNT/EPU CPE) to detect ascorbic acid. The result exhibited that the detection limit of AF-MWCNT/EPU CPE was 3.5 μM which is lower than EPU CPE (6.1 μM). According to the result, the AF-MWCNT/EPU-CPE shows great sensitivity and repeatability for determination of AA.
Second, we synthesis a searis of electroactive polymer, poly(o-methoxyaniline) (POMA), POMA/Carbon nanotube composites, sulfonated polyaniline, by oxidative polymerization, and used them to apply in the growth of neural stem cells (NSCs). The previous study evidenced POMA is a biocompatibility material in our group. Therefore, we prepared the neat electrospun poly(o-methoxyaniline) (POMA) fibers to disscuss the ability of POMA fibers for attachment, proliferation, and differentiation. These results indicate that POMA not only improved NSC growth, but also enhanced differentiation of NSCs into the neurons and astrocytes. There are 74% of the fully differentiated neurons has intracellular Ca2+ response when treating with high conc. KCl. Besides, we fabricated the POMA/CNT composites in order to enhance the conductivity of POMA and apply the direct current to these composites. However, there is a broken circuit without acid doping of POMA. In the last section, sulfonated polyanilin (SPAN) was synthesized by oxidative polymerization of aniline and metaniline acid. The character of chemical oxidation of SPAN was monitoring by UV-vis and the electroactivity of the SPAN was evaluated by CV. The sulfonated polyaniline is capable of self-doping. We fabricated SPAN-based electrical stimulation device. We hope that the organic material may find utility in electrical stimulation of NSCs for differentiation and can be a potential substrate for the development of NSCs for tissue engineering and neuroscience research applications.

並列關鍵字

electroactive polymer；sensor；Neural stem cell

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