Filtern
Dokumenttyp
- Zeitschriftenartikel (18)
- Posterpräsentation (7)
- Vortrag (3)
- Sonstiges (1)
Sprache
- Englisch (17)
- Deutsch (11)
- Mehrsprachig (1)
Schlagworte
- Silver nanoparticles (5)
- Nanoparticles (4)
- Nanoparticle (3)
- Oxidative stress (3)
- Protein carbonyls (3)
- Cellular internalization (2)
- ICP-MS (2)
- Laser-SNMS (2)
- Nanosilver (2)
- Neurons (2)
- Reference material (2)
- SAXS (2)
- Small-angle X-ray scattering (2)
- 2D gel electrophoresis (1)
- Absolute dose (1)
- Ag/peptide@SiO2 nanostructures (1)
- Antibody (1)
- Bio-Interfaces (1)
- Bioimaging (1)
- Bundesoberbehörden (1)
- Calcium (1)
- Carbohydrates (1)
- Cell (1)
- Chiral nanoparticles (1)
- Comparison measurement (1)
- Confocal Raman microscopy (1)
- Core shell (1)
- Core-shell structures (1)
- Dynamic light scattering (1)
- Ecotoxicity (1)
- Einzelzellanalyse (1)
- Exposure (1)
- FIB/SEM slice and view (1)
- Fluorophore (1)
- Forschungsstrategie (1)
- Hybrid materials (1)
- Imaging (1)
- Innovative Werkstoffe (1)
- Instrumentation (1)
- Isoelectric point (1)
- LA-ICP-MS based immunoassays (1)
- Laser ablation ICP-MS (1)
- Life sciences (1)
- Lipidomics (1)
- Macrophage (1)
- Mass cytometry (1)
- N-acetyl cysteine (1)
- Nano (1)
- Nanomaterial suspension (1)
- Nanomaterialien (1)
- Nanomaterials (1)
- Nanotoxicity (1)
- Nanotoxicology (1)
- Neurotoxicology (1)
- Peptide coating (1)
- Peptide-templated materials (1)
- Phagocytosis (1)
- Protein association (1)
- ROS (1)
- SC-ICP-MS (1)
- Silbernanopartikel (1)
- Silver (1)
- Silver nanoparticle (1)
- Single Cell Analysis (1)
- Single particle ICP-MS (1)
- Standard operation procedure (1)
- Standardization (1)
- TOF-SIMS (1)
- Three-dimensional depth profiling (1)
- ToF-SIMS (1)
- Toxicity (1)
Organisationseinheit der BAM
Eingeladener Vortrag
- nein (3)
Biomimetic synthesis of chiral erbium-doped silver/peptide/silica core-shell nanoparticles (ESPN)
(2011)
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 Er2O3 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.
In the body, nanoparticles can be systemically distributed and then may affect secondary target organs, such as the central nervous system (CNS). Putative adverse effects on the CNS are rarely investigated to date. Here, we used a mixed primary cell model consisting mainly of neurons and astrocytes and a minor proportion of oligodendrocytes to analyze the effects of well-characterized 20 and 40 nm silver nanoparticles (SNP). Similar gold nanoparticles served as control and proved inert for all endpoints tested. SNP induced a strong size-dependent cytotoxicity. Additionally, in the low concentration range (up to 10 µg/ml of SNP), the further differentiated cultures were more sensitive to SNP treatment. For detailed studies, we used low/medium dose concentrations (up to 20 µg/ml) and found strong oxidative stress responses. Reactive oxygen species (ROS) were detected along with the formation of protein carbonyls and the induction of heme oxygenase-1. We observed an acute calcium response, which clearly preceded oxidative stress responses. ROS formation was reduced by antioxidants, whereas the calcium response could not be alleviated by antioxidants. Finally, we looked into the responses of neurons and astrocytes separately. Astrocytes were much more vulnerable to SNP treatment compared with neurons. Consistently, SNP were mainly taken up by astrocytes and not by neurons. Immunofluorescence studies of mixed cell cultures indicated stronger effects on astrocyte morphology. Altogether, we can demonstrate strong effects of SNP associated with calcium dysregulation and ROS formation in primary neural cells, which were detectable already at moderate dosages.
Silver nanoparticles (SNPs) are among the most commercialized nanoparticles because of their antibacterial effects. Besides being employed, e.g. as a coating material for sterile surfaces in household articles and appliances, the particles are also used in a broad range of medical applications. Their antibacterial properties make SNPs especially useful for wound disinfection or as a coating material for prostheses and surgical instruments. Because of their optical characteristics, the particles are of increasing interest in biodetection as well. Despite the widespread use of SNPs, there is little knowledge of their toxicity. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) and laser post-ionization secondary neutral mass spectrometry (Laser-SNMS) were used to investigate the effects of SNPs on human macrophages derived from THP-1 cells in vitro. For this purpose, macrophages were exposed to SNPs. The SNP concentration ranges were chosen with regard to functional impairments of the macrophages. To optimize the analysis of the macrophages, a special silicon wafer sandwich preparation technique was employed; ToF-SIMS was employed to characterize fragments originating from macrophage cell membranes. With the use of this optimized sample preparation method, the SNP-exposed macrophages were analyzed with ToF-SIMS and with Laser-SNMS. With Laser-SNMS, the three-dimensional distribution of SNPs in cells could be readily detected with very high efficiency, sensitivity, and submicron lateral resolution. We found an accumulation of SNPs directly beneath the cell membrane in a nanoparticular state as well as agglomerations of SNPs inside the cells.
Silver nanoparticles (SNP) are among the most commercialized nanoparticles. Here, we show that peptide-coated SNP cause functional impairment of human macrophages. A dose-dependent inhibition of phagocytosis is observed after nanoparticle treatment, and pretreatment of cells with N-acetyl cysteine (NAC) can counteract the phagocytosis disturbances caused by SNP.
Using the surface-sensitive mode of time-of-flight secondary ion mass spectrometry, in combination with multivariate statistical methods, we studied the composition of cell membranes in human macrophages upon exposure to SNP with and without NAC preconditioning. This method revealed characteristic changes in the lipid pattern of the cellular membrane outer leaflet in those cells challenged by SNP. Statistical analyses resulted in 19 characteristic ions, which can be used to distinguish between NAC pretreated and untreated macrophages. The present study discusses the assignments of surface cell membrane phospholipids for the identified ions and the resulting changes in the phospholipid pattern of treated cells. We conclude that the adverse effects in human macrophages caused by SNP can be partially reversed through NAC administration. Some alterations, however, remained.
Silver nanoparticles (SNPs) are among the
most commercialized nanoparticles worldwide. Often SNP
are used because of their antibacterial properties. Besides
that they possess unique optic and catalytic features,
making them highly interesting for the creation of novel
and advanced functional materials. Despite its widespread
use only little data exist in terms of possible adverse effects
of SNP on human health. Conventional synthesis routes
usually yield products of varying quality and property. It
thus may become puzzling to compare biological data from
different studies due to the great variety in sizes, coatings
or shapes of the particles applied. Here, we applied a novel
synthesis approach to obtain SNP of well-defined colloidal
and structural properties. Being stabilized by a covalently
linked small peptide, these particles are nicely homogenous,
with narrow size distribution, and form monodisperse
suspensions in aqueous solutions. We applied these peptide-
coated SNP in two different sizes of 20 or 40 nm
(Ag20Pep and Ag40Pep) and analyzed responses of THP-
1-derived human macrophages while being exposed against
these particles. Gold nanoparticles of similar size and
coating (Au20Pep) were used for comparison. The cytotoxicity
of particles was assessed by WST-1 and LDH
assays, and the uptake into the cells was confirmed via
transmission electron microscopy. In summary, our data
demonstrate that this novel type of SNP is well suited to
serve as model system for nanoparticles to be tested in
toxicological studies in vitro.