共价功能化对单壁碳纳米管产生DNA损伤和活性氧的影响研究 |
摘要点击 2283 全文点击 1455 投稿时间:2011-11-29 修订日期:2012-01-12 |
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中文关键词 单壁碳纳米管 共价功能化 DNA损伤 NADH ROS |
英文关键词 single-walled carbon nanotubes (SWNTs) covalent functionalization DNA cleavage NADH ROS |
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中文摘要 |
以质粒DNA评价法表征了不同程度共价功能化单壁碳纳米管(SWNTs)的生物毒性,并在近红外-可见光光谱、拉曼光谱和活性氧(ROS)表征的基础上研究了共价功能化对其物理结构和化学活性的影响. 结果表明,共价功能化增强了碳纳米管对质粒DNA的损伤程度,3种不同类型的碳纳米管对DNA损伤的强度为羧基功能化SWNTs (SWNT-COOH)>聚乙二醇功能化SWNTs (SWNT-PEG)>非共价功能化SWNTs (uSWNTs). 随着共价功能化程度的加深,碳纳米管表面石墨晶格的sp2 结构受损程度逐渐增高,以致使其反应活性增大. 共价功能化后SWNTs可作为电子转移中间体将NADH中的电子转移至O2并生成ROS从而对DNA造成损伤. |
英文摘要 |
Biotoxicity of selected covalent functionalizaed single-walled carbon nanotubes (SWNTs) was investigated by plasmid DNA cleavage assay. The effect of covalent functionalization on the physical structural and chemical activity of SWNTs was also studied by Vis-NIR spectroscopy, Raman spectroscopy and ROS assay. The DNA cleavage intensity was promoted by covalent functionalization, and the intensity of DNA damage caused by the three types of carbon nanotubes in a descending order was found to be carboxylated SWNTs (SWNT-COOH)>polyethyleneglycol-lated SWNTs (SWNT-PEG)>uncovalent functionalized SWNTs (uSWNTs). SWNTs were efficient intermediate to trigger electron transfer from electron donor to O2 in dark condition which lead to superoxide radical (O2·-) formation. The electron transfer intensity caused by selected SWNTs was also SWNT-COOH>SWNT-PEG>SWNTs. The reason is that defect sites which changed from sp2-hybridized carbon atom on the side wall of carbon nanotubes were more reactive than the perfect ones. |