Henss Anja, Otto Svenja-K, Schaepe Kaija, Pauksch Linda, Lips Katrin S, Rohnke Marcus
Institute for Physical Chemistry, Justus Liebig University Giessen, Giessen 35392, Germany.
Laboratory of Experimental Trauma Surgery, Justus Liebig University Giessen, Giessen 35392, Germany.
Biointerphases. 2018 Feb 28;13(3):03B410. doi: 10.1116/1.5015957.
Within this study, the authors use human mesenchymal stem cells incubated with silver nanoparticles (AgNPs) as a model system to systematically investigate the advantages and drawbacks of the fast imaging delayed extraction mode for two-dimensional and three-dimensional (3D) analyses at the cellular level. The authors compare the delayed extraction mode with commonly employed measurement modes in terms of mass and lateral resolution, intensity, and dose density. Using the delayed extraction mode for single cell analysis, a high mass resolution up to 4000 at m/z = 184.08 combined with a lateral resolution up to 360 nm is achieved. Furthermore, the authors perform 3D analyses with Ar-clusters (10 keV) and O (500 eV) as sputter species, combined with Bi and delayed extraction for analysis. Cell compartments like the nucleus are visualized in 3D, whereas no realistic 3D reconstruction of intracellular AgNP is possible due to the different sputter rates of inorganic and organic cell materials. Furthermore, the authors show that the sputter yield of Ag increases with the decreasing Ar-cluster size, which might be an approach to converge the different sputter rates.
在本研究中，作者使用与银纳米颗粒（AgNPs）孵育的人间充质干细胞作为模型系统，系统地研究快速成像延迟提取模式在细胞水平二维和三维（3D）分析中的优缺点。作者在质量和横向分辨率、强度和剂量密度方面，将延迟提取模式与常用的测量模式进行了比较。使用延迟提取模式进行单细胞分析，在m/z = 184.08时可实现高达4000的高质量分辨率，同时横向分辨率高达360 nm。此外，作者使用Ar簇（10 keV）和O（500 eV）作为溅射物种进行3D分析，并结合Bi和延迟提取进行分析。细胞核等细胞区室以3D形式可视化，然而，由于无机和有机细胞材料的溅射速率不同，无法对细胞内AgNP进行实际的3D重建。此外，作者表明，Ag的溅射产率随着Ar簇尺寸的减小而增加，这可能是一种使不同溅射速率趋于一致的方法。
