Phillips C L, Yah C S, Iyuke S E, Pillay V, Rumbold K, Choonara Y
School of Chemical and Metallurgical Engineering, University of the Witwatersrand, Johannesburg, P/Bag 3, Wits 2050, South Africa.
Department of Pharmacy and Pharmacology, School of Therapeutic Sciences, University of the Witwatersrand, 7 York Road, Parktown, 2193 Johannesburg, South Africa.
Afr Health Sci. 2013 Dec;13(4):947-54. doi: 10.4314/ahs.v13i4.13.
The applications of oxidized carbon nanotubes (o-CNTs) have shown potentials in novel drug delivery including the brain which is usually a challenge. This underscores the importance to study its potential toxic effect in animals. Despite being a promising tool for biomedical applications little is known about the safety of drugs in treating brain diseases. The toxicity of oxidized multi-walled carbon nanotubes (o-MWCNTs) are of utmost concern and in most in-vitro studies conducted so far are on dendritic cell (DC) lines with limited data on PC12 cell lines.
We focused on the effect of o-MWCNTs in PC12 cells in vitro: a common model cell for neurotoxicity.
The pristine multi-walled carbon nanotubes (p-MWCNTs) were produced by the swirled floating catalytic chemical vapour deposition method (SFCCVD). The p-MWCNTs were then oxidized using purified H2SO4/HNO3 (3:1v/v) and 30% HNO3 acids to produce o-MWCNTs. The Brunauer-Emmett-Teller (BET), transmission electron microscopy (TEM), Scanning electron microscopy (SEM), thermogravimetric analyser (TGA) and Raman spectroscopy techniques were used to characterize the MWCNTs. The PC12 cells were cultured in RPMI medium containing concentrations of o-MWCNTs ranging from 50 to 200 µg/ml.
The o-MWCNTs demonstrated slight cytotoxicity at short time period to PC12 neuronal cells whilst at longer time period, no significant (p > 0.05) toxicity was observed due to cell recovery.
In conclusion, the o-MWCNTs did not affect the growth rate and viability of the PC12 cells due to lack of considerable toxicity in the cells during the observed time period but further investigations are required to determine cell recovery mechanism.
氧化碳纳米管（o-CNTs）的应用在新型药物递送方面展现出潜力，包括向通常颇具挑战的脑部递送药物。这凸显了研究其在动物体内潜在毒性作用的重要性。尽管氧化多壁碳纳米管（o-MWCNTs）是生物医学应用的一种有前景的工具，但对于治疗脑部疾病药物的安全性知之甚少。氧化多壁碳纳米管（o-MWCNTs）的毒性备受关注，且迄今为止大多数体外研究针对的是树突状细胞（DC）系，而关于PC12细胞系的数据有限。
我们聚焦于o-MWCNTs对PC12细胞的体外影响，PC12细胞是神经毒性研究中常用的模型细胞。
通过漩涡流动催化化学气相沉积法（SFCCVD）制备原始多壁碳纳米管（p-MWCNTs）。然后使用纯化的硫酸/硝酸（3:1 v/v）和30%硝酸对p-MWCNTs进行氧化，以制备o-MWCNTs。采用布鲁诺尔-埃米特-泰勒（BET）法、透射电子显微镜（TEM）、扫描电子显微镜（SEM）、热重分析仪（TGA）和拉曼光谱技术对多壁碳纳米管进行表征。将PC12细胞培养于含有浓度范围为50至200μg/ml的o-MWCNTs的RPMI培养基中。
o-MWCNTs在短时间内对PC12神经元细胞表现出轻微细胞毒性，而在较长时间内，由于细胞恢复，未观察到显著（p>0.05）毒性。
总之，在观察期间，o-MWCNTs对PC12细胞的生长速率和活力没有影响，因为细胞中缺乏相当大的毒性，但需要进一步研究以确定细胞恢复机制。
