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  - Graf, Philipp
A1  - Mantion, Alexandre
A1  - Haase, Andrea
A1  - Thuenemann, Andreas F.
A1  - Masic, Admir
A1  - Meier, Wolfgang P.
A1  - Luch, Andreas
A1  - Taubert, Andreas
T1  - Silicification of peptide-coated silver nanoparticles-A biomimetic soft chemistry approach toward chiral hybrid core-shell materials
JF  - ACS nano
N2  - Silica and silver nanoparticles are relevant materials for new applications in optics, medicine, and analytical chemistry. We have previously reported the synthesis of pH responsive, peptide-templated, chiral silver nanoparticles. The current report shows that peptide-stabilized nanoparticles can easily be coated with a silica shell by exploiting the ability of the peptide coating to hydrolyze silica precursors such as TEOS or TMOS. The resulting silica layer protects the nanoparticles from chemical etching, allows their inclusion in other materials, and renders them biocompatible. Using electron and atomic force microscopy, we show that the silica shell thickness and the particle aggregation can be controlled simply by the reaction time. Small-angle X ray scattering confirms the Ag/peptide@silica core-shell structure. UV-vis and circular dichroism spectroscopy prove the conservation of the silver nanoparticle chirality upon silicification. Biological tests show that the biocompatibility in simple bacterial systems is significantly improved once a silica layer is deposited on the silver particles.
KW  - peptide-templated materials
KW  - silver nanoparticles
KW  - chiral nanoparticles
KW  - Ag/peptide@SiO(2) nanostructures
KW  - core-shell structures
Y1  - 2011
U6  - https://doi.org/10.1021/nn102969p
SN  - 1936-0851
VL  - 5
IS  - 2
SP  - 820
EP  - 833
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Mantion, Alexandre
A1  - Graf, Philipp
A1  - Florea, Ileana
A1  - Haase, Andrea
A1  - Thuenemann, Andreas F.
A1  - Masic, Admir
A1  - Ersen, Ovidiu
A1  - Rabu, Pierre
A1  - Meier, Wolfgang P.
A1  - Luch, Andreas
A1  - Taubert, Andreas
T1  - Biomimetic synthesis of chiral erbium-doped silver/peptide/silica core-shell nanoparticles (ESPN)
JF  - Nanoscale
N2  - Peptide-modified silver nanoparticles have been coated with an erbium-doped silica layer using a method inspired by silica biomineralization. Electron microscopy and small-angle X-ray scattering confirm the presence of an Ag/peptide core and silica shell. The erbium is present as small Er(2)O(3) particles in and on the silica shell. Raman, IR, UV-Vis, and circular dichroism spectroscopies show that the peptide is still present after shell formation and the nanoparticles conserve a chiral plasmon resonance. Magnetic measurements find a paramagnetic behavior. In vitro tests using a macrophage cell line model show that the resulting multicomponent nanoparticles have a low toxicity for macrophages, even on partial dissolution of the silica shell.
Y1  - 2011
U6  - https://doi.org/10.1039/c1nr10930h
SN  - 2040-3364
VL  - 3
IS  - 12
SP  - 5168
EP  - 5179
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  -