Mihalchik Amy L, Ding Weiqiang, Porter Dale W, McLoughlin Colleen, Schwegler-Berry Diane, Sisler Jennifer D, Stefaniak Aleksandr B, Snyder-Talkington Brandi N, Cruz-Silva Rodolfo, Terrones Mauricio, Tsuruoka Shuji, Endo Morinobu, Castranova Vincent, Qian Yong
Pharmaceutical and Pharmacological Sciences, West Virginia University School of Pharmacy, Morgantown, WV 26505, United States; Pathology and Physiology Research Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, United States.
Shared Research Facilities, West Virginia University, Morgantown, WV 26505, United States.
Toxicology. 2015 Jul 3;333:25-36. doi: 10.1016/j.tox.2015.03.008. Epub 2015 Mar 20.
Nitrogen-doped multi-walled carbon nanotubes (ND-MWCNTs) are modified multi-walled carbon nanotubes (MWCNTs) with enhanced electrical properties that are used in a variety of applications, including fuel cells and sensors; however, the mode of toxic action of ND-MWCNT has yet to be fully elucidated. In the present study, we compared the interaction of ND-MWCNT or pristine MWCNT-7 with human small airway epithelial cells (SAEC) and evaluated their subsequent bioactive effects. Transmission electron microscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, and X-ray diffraction suggested the presence of N-containing defects in the lattice of the nanotube. The ND-MWCNTs were determined to be 93.3% carbon, 3.8% oxygen, and 2.9% nitrogen. A dose-response cell proliferation assay showed that low doses of ND-MWCNT (1.2μg/ml) or MWCNT-7 (0.12μg/ml) increased cellular proliferation, while the highest dose of 120μg/ml of either material decreased proliferation. ND-MWCNT and MWCNT-7 appeared to interact with SAEC at 6h and were internalized by 24h. ROS were elevated at 6 and 24h in ND-MWCNT exposed cells, but only at 6h in MWCNT-7 exposed cells. Significant alterations to the cell cycle were observed in SAEC exposed to either 1.2μg/ml of ND-MWCNT or MWCNT-7 in a time and material-dependent manner, possibly suggesting potential damage or alterations to cell cycle machinery. Our results indicate that ND-MWCNT induce effects in SAEC over a time and dose-related manner which differ from MWCNT-7. Therefore, the physicochemical characteristics of the materials appear to alter their biological effects.
氮掺杂多壁碳纳米管（ND-MWCNTs）是经过改性的多壁碳纳米管（MWCNTs），其电学性能得到增强，可用于包括燃料电池和传感器在内的多种应用；然而，ND-MWCNT的毒性作用模式尚未完全阐明。在本研究中，我们比较了ND-MWCNT或原始MWCNT-7与人小气道上皮细胞（SAEC）的相互作用，并评估了它们随后的生物活性效应。透射电子显微镜、X射线光电子能谱、拉曼光谱和X射线衍射表明纳米管晶格中存在含氮缺陷。测定ND-MWCNTs含93.3%的碳、3.8%的氧和2.9%的氮。剂量反应细胞增殖试验表明，低剂量的ND-MWCNT（1.2μg/ml）或MWCNT-7（0.12μg/ml）可促进细胞增殖，而两种材料的最高剂量120μg/ml则会抑制增殖。ND-MWCNT和MWCNT-7在6小时时似乎与SAEC相互作用，并在24小时时被内化。暴露于ND-MWCNT的细胞在6小时和24小时时活性氧水平升高，但暴露于MWCNT-7的细胞仅在第6小时升高。在暴露于1.2μg/ml的ND-MWCNT或MWCNT-7的SAEC中，观察到细胞周期有明显变化，且具有时间和材料依赖性，这可能表明细胞周期机制受到潜在损伤或改变。我们的结果表明，ND-MWCNT在SAEC中随时间和剂量产生的效应与MWCNT-7不同。因此，材料的物理化学特性似乎会改变它们的生物学效应。
