Laboratory of Chromatin Biology, Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S.A.S. Nagar, Mohali 160 062, Punjab, India.
Food Chem Toxicol. 2013 Jan;51:1-14. doi: 10.1016/j.fct.2012.08.044. Epub 2012 Aug 30.
Silver nanoparticles (AgNPs) are one of the most commercially viable nanotechnological products, nevertheless; safety issues are raised regarding the use of such nanoparticles due to unintentional health and environmental impacts. In the present study, AgNPs were synthesized by chemically reducing silver nitrate alternatively with sodium borohydride, tannic acid, ascorbic acid and sodium citrate. AgNPs synthesized by reduction with tannic acid (TSNPs) and sodium borohydride (BSNPs) exhibited highest and lowest surface potential respectively. Therefore these two types of AgNPs were selected for their toxicity assessment in cellular environment. We treated skin epithelial A431, lung epithelial A549 and murine macrophages RAW264.7 cells with AgNPs over a range of doses (5-100μg/ml). Toxicity was evaluated by measuring changes in cellular morphology, ROS generation, metabolic activity and expression of various stress markers. Interestingly, TSNPs exhibited a higher negative zeta-potential and also higher toxicity. Higher toxicity of TSNPs was attested by dose-dependent increase in cellular disruption and ROS generation. BSNPs showed cytotoxic effect up to the concentration of 50μg/ml and thereafter the cytotoxic effect attenuated. TSNPs induced a dose dependent increase in the expression of stress markers pp38, TNF-α and HSP-70. Our report proposes that cytotoxicity of AgNPs changes with surface potential of nanoparticles and cells type.
银纳米粒子（AgNPs）是最具商业可行性的纳米技术产品之一，然而，由于这些纳米粒子对健康和环境的潜在影响，其使用引发了安全问题。在本研究中，AgNPs 通过化学还原法分别用硼氢化钠、没食子酸、抗坏血酸和柠檬酸钠还原硝酸银合成。用没食子酸还原得到的 AgNPs（TSNPs）和用硼氢化钠还原得到的 AgNPs（BSNPs）的表面电势最高和最低。因此，选择这两种类型的 AgNPs 进行细胞环境中的毒性评估。我们用不同剂量（5-100μg/ml）的 AgNPs 处理皮肤上皮细胞 A431、肺上皮细胞 A549 和鼠源巨噬细胞 RAW264.7。通过测量细胞形态变化、ROS 生成、代谢活性和各种应激标志物的表达来评估毒性。有趣的是，TSNPs 具有更高的负 zeta 电位，毒性也更高。TSNPs 的更高毒性通过细胞破坏和 ROS 生成的剂量依赖性增加得到证实。BSNPs 在 50μg/ml 浓度以下表现出细胞毒性作用，此后细胞毒性作用减弱。TSNPs 诱导应激标志物 pp38、TNF-α 和 HSP-70 的表达呈剂量依赖性增加。我们的报告表明，AgNPs 的细胞毒性随纳米粒子的表面电势和细胞类型而变化。
