TY  - JOUR
A1  - Haase, Andrea
A1  - Arlinghaus, Heinrich F.
A1  - Tentschert, Jutta
A1  - Jungnickel, Harald
A1  - Graf, Philipp
A1  - Mantion, Alexandre
A1  - Draude, Felix
A1  - Galla, Sebastian
A1  - Plendl, Johanna
A1  - Goetz, Mario E.
A1  - Masic, Admir
A1  - Meier, Wolfgang P.
A1  - Thuenemann, Andreas F.
A1  - Taubert, Andreas
A1  - Luch, Andreas
T1  - Application of Laser Postionization Secondary Neutral Mass Spectrometry/Time-of-Flight Secondary Ion Mass Spectrometry in Nanotoxicology: Visualization of Nanosilver in Human Macrophages and Cellular Responses
JF  - ACS nano
N2  - 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.
KW  - nanosilver
KW  - Laser-SNMS
KW  - TOF-SIMS
KW  - confocal Raman microscopy
KW  - oxidative stress
KW  - protein carbonyls
Y1  - 2011
U6  - https://doi.org/10.1021/nn200163w
SN  - 1936-0851
VL  - 5
IS  - 4
SP  - 3059
EP  - 3068
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Draude, Felix
A1  - Körsgen, Martin
A1  - Pelster, Andreas
A1  - Schwerdtle, Tanja
A1  - Müthing, Johannes
A1  - Arlinghaus, Heinrich F.
T1  - Characterization of freeze-fractured epithelial plasma membranes on nanometer scale with ToF-SIMS
JF  - Analytical & bioanalytical chemistry
N2  - Time-of-flight secondary ion mass spectrometry (ToF-SIMS) was used to characterize the freeze-fracturing process of human epithelial PANC-1 and UROtsa cells. For this purpose, phosphatidylcholine, sphingomyelin, phosphatidylethanolamine, and phosphatidylserine standard samples were investigated to find specific signals with both high specificity and signal intensity. The results were used to investigate single cells of subconfluent cell layers prepared with a special silicon wafer sandwich preparation technique. This freeze-fracturing technique strips cell membranes off the cells, isolating them on opposing silicon wafer substrates. Criteria were found for defining regions with stripped off cell membranes and, on the opposing wafer, complementary regions with the remaining cells. Measured ethanolamine/choline and serine/choline ratios in these regions clearly showed that in the freeze-fracturing process, the lipid bilayer of the plasma membrane is split along its central zone. Accordingly, only the outer lipid monolayer is stripped off the cell, while the inner lipid monolayer remains attached to the cell on the opposing wafer, thus allowing detailed analysis of a single lipid monolayer. Furthermore, it could be shown that using different washing procedures did not influence the transmembrane lipid distribution. Under optimized preparation conditions, it became feasible to detect lipids with a lateral resolution of approximately 100 nm. The data indicate that ToF-SIMS would be a very useful technique to study with very high lateral resolution changes in lipid composition caused, for example, by lipid storage diseases or pharmaceuticals that interfere with the lipid metabolism.
KW  - ToF-SIMS imaging
KW  - Life science
KW  - Lipid
KW  - Freeze-fracturing
KW  - Membrane
KW  - Transmembrane asymmetry
Y1  - 2015
U6  - https://doi.org/10.1007/s00216-014-8334-2
SN  - 1618-2642
SN  - 1618-2650
VL  - 407
IS  - 8
SP  - 2203
EP  - 2211
PB  - Springer
CY  - Heidelberg
ER  -