多壁碳纳米管-神经生长因子复合物的制备及生物活性测定

为探讨采用羧基化多壁碳纳米管（MWCNTs—COOH）非共价接枝神经生长因子（NGF）制备碳纳米管神经生长因子（MWCNTsNGF）复合物，考察复合物的生物活性。采用透射电子显微镜（TEM）表征MWCNTs—NGF复合物的微观形貌，酶联免疫吸附法（ELISA法）测定MWCNTs—NGF复合物载带NGF的量，MTT法测定了MWCNTs—NGF复合物的对嗜铬细胞瘤细胞（PCI2细胞）的毒性，PCI2细胞培养法评价复合物的生物活性，TEM表征复合物与细胞的分布情况。结果：TEM图像表明NGF连接到了MWCNT上，EI．ISA法测得MWCNTsNGF复合物载带NGF的量为797．63pg／mg，MWCNTs—NGF复合物对PCI2细胞有一定的毒性，生物活性试验表明NGF浓度相同的情况下，MwCNTs—NGF复合物组PCI2细胞的分化率明显高于NGF组。TEM图像表明碳纳米管能进入细胞。结论：碳纳米管能载带NGF进入细胞，使NGF能更好的表达生物活性。

Preparation and Bioassay of Multi-Walled Carbon Nanotubes-Nerve Growth Factor Complex

Objective：To prepare complex of carbon nanotubes nerve growth factor （MWCNTs-NGF） through the method of non-eovalently grafting, and investigate the bioactivity of the complexes. Methods： We characterized the morphology of the MWCNTs-NGF complex using transmission electron microscopy（TEM）,determined the amount of NGF that MWCNTs NGF complex carried with the method of enzyme-linked immunosorhent assay（ELISA）, evaluated the cytotoxicity of the complexes by the method of MTT, evaluated the biological activity of the MWCNTs NGF complex through cultured pheochromocytoma cells （PC12 cells）, and characterized the distribution of the complex with the cells using TEM. Results：TEM images showed that NGF was connected to the MWCNTs,the result of ELISA measured the amount of NGF that MWCNTs-NGF complex carried was 797.63pg . mg, MTT tests showed that the MWCNTs-NGF complex have some toxicity on PC12 cells, biological ac tivity tests showed that the differentiation of MWCNTs NGF complex group on PC12 cells was significantly higher than the NGF group in the case of the same concentration of NGF, and TEM images showed that carbon nanotubes could enter cells. Conclusion：Carhon nanotubes can carry NGF protein into the cells and help to promote nerve cell growth.