German Federal Institute for Risk Assessment (BfR), Department of Product Safety, Thielallee 88-92, 14195 Berlin, Germany.
ACS Nano. 2011 Apr 26;5(4):3059-68. doi: 10.1021/nn200163w. Epub 2011 Apr 2.
Silver nanoparticles (SNP) are the subject of worldwide commercialization because of their antimicrobial effects. Yet only little data on their mode of action exist. Further, only few techniques allow for visualization and quantification of unlabeled nanoparticles inside cells. To study SNP of different sizes and coatings within human macrophages, we introduce a novel laser postionization secondary neutral mass spectrometry (Laser-SNMS) approach and prove this method superior to the widely applied confocal Raman and transmission electron microscopy. With time-of-flight secondary ion mass spectrometry (TOF-SIMS) we further demonstrate characteristic fingerprints in the lipid pattern of the cellular membrane indicative of oxidative stress and membrane fluidity changes. Increases of protein carbonyl and heme oxygenase-1 levels in treated cells confirm the presence of oxidative stress biochemically. Intriguingly, affected phagocytosis reveals as highly sensitive end point of SNP-mediated adversity in macrophages. The cellular responses monitored are hierarchically linked, but follow individual kinetics and are partially reversible.
由于具有抗菌作用，纳米银颗粒（SNP）成为了全球商业化的研究对象。然而，关于其作用模式的资料却很少。此外，只有少数技术可以在不进行标记的情况下可视化和定量分析细胞内的纳米颗粒。为了研究不同大小和涂层的 SNP 在人巨噬细胞中的作用，我们引入了一种新的激光后电离二次中性质谱（Laser-SNMS）方法，并证明该方法优于广泛应用的共聚焦拉曼和透射电子显微镜。通过飞行时间二次离子质谱（TOF-SIMS），我们进一步证明了细胞膜中脂质模式的特征指纹，表明存在氧化应激和膜流动性变化。处理细胞中蛋白质羰基和血红素加氧酶-1 水平的增加证实了生物化学上存在氧化应激。有趣的是，受影响的吞噬作用揭示了 SNP 介导的巨噬细胞逆境的高度敏感终点。所监测的细胞反应是层次化关联的，但遵循个体动力学且部分是可逆的。
