TY - JOUR A1 - Graf, P. A1 - Mantion, Alexandre A1 - Haase, A. A1 - Thünemann, Andreas A1 - Masic, A. A1 - Meier, W. A1 - Luch, A. A1 - Taubert, A. T1 - Silicification of peptide-coated silver nanoparticles - a biomimetic soft chemistry approach toward chiral hybrid core-shell materials 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@SiO2 nanostructures KW - Core-shell structures PY - 2011 U6 - https://doi.org/10.1021/nn102969p SN - 1936-0851 VL - 5 IS - 2 SP - 820 EP - 833 PB - ACS Publ. CY - Washington, DC, USA AN - OPUS4-23207 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Haase, A. A1 - Tentschert, J. A1 - Jungnickel, H. A1 - Graf, P. A1 - Mantion, Alexandre A1 - Draude, F. A1 - Plendl, J. A1 - Goetz, M.E. A1 - Galla, S. A1 - Masic, A. A1 - Thünemann, Andreas A1 - Taubert, A. A1 - Arlinghaus, H. F. A1 - Luch, A. T1 - Toxicity of silver nanoparticles in human macrophages: uptake, intracellular distribution and cellular responses N2 - Silver nanoparticles (SNP) are among the most commercialized nanoparticles worldwide. They can be found in many diverse products, mostly because of their antibacterial properties. Despite its widespread use only little data on possible adverse health effects exist. It is difficult to compare biological data from different studies due to the great variety in sizes, coatings or shapes of the particles. Here, we applied a novel synthesis approach to obtain SNP, which are covalently stabilized by a small peptide. This enables a tight control of both size and shape. We applied these SNP in two different sizes of 20 or 40 nm (Ag20Pep and Ag40Pep) and analyzed responses of THP-1-derived human macrophages. Similar gold nanoparticles with the same coating (Au20Pep) were used for comparison and found to be non-toxic. We assessed the cytotoxicity of particles and confirmed their cellular uptake via transmission electron microscopy and confocal Raman microscopy. Importantly a majority of the SNP could be detected as individual particles spread throughout the cells. Furthermore we studied several types of oxidative stress related responses such as induction of heme oxygenase I or formation of protein carbonyls. In summary, our data demonstrate that even low doses of SNP exerted adverse effects in human macrophages. KW - Silver nanoparticles KW - Neurotoxicology KW - Protein carbonyls KW - ROS PY - 2011 U6 - https://doi.org/10.1088/1742-6596/304/1/012030 SN - 1742-6588 SN - 1742-6596 VL - 304 SP - 012030-1 - 012030-14 PB - IOP Publ. CY - Bristol, UK AN - OPUS4-24035 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Haase, A. A1 - Rott, S. A1 - Mantion, Alexandre A1 - Graf, P. A1 - Plendl, J. A1 - Thünemann, Andreas A1 - Meier, W.P. A1 - Taubert, A. A1 - Luch, A. A1 - Reiser, G T1 - Effects of silver nanoparticles on primary mixed neural cell cultures: uptake, oxidative stress and acute calcium responses N2 - 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. KW - Silver nanoparticles KW - Neurons KW - Oxidative stress KW - Protein carbonyls KW - Calcium KW - Reference material KW - Nanoparticle KW - Small-angle X-ray scattering KW - SAXS PY - 2012 U6 - https://doi.org/10.1093/toxsci/kfs003 SN - 1096-6080 SN - 1096-0929 VL - 126 IS - 2 SP - 457 EP - 468 PB - Oxford University Press CY - Oxford AN - OPUS4-25633 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tentschert, J. A1 - Draude, F. A1 - Jungnickel, H. A1 - Haase, A. A1 - Mantion, Alexandre A1 - Galla, S. A1 - Thünemann, Andreas A1 - Taubert, A. A1 - Luch, A. A1 - Arlinghaus, H. F. T1 - TOF-SIMS analysis of cell membrane changes in functional impaired human macrophages upon nanosilver treatment N2 - 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. KW - Silver nanoparticles KW - Lipidomics KW - N-acetyl cysteine KW - Phagocytosis KW - Oxidative stress KW - Reference material PY - 2013 U6 - https://doi.org/10.1002/sia.5155 SN - 0142-2421 SN - 1096-9918 VL - 45 IS - 1 SP - 483 EP - 485 PB - Wiley CY - Chichester AN - OPUS4-27586 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Haase, A. A1 - Mantion, Alexandre A1 - Graf, P. A1 - Plendl, J. A1 - Thünemann, Andreas A1 - Meier, W. A1 - Taubert, A. A1 - Luch, A. T1 - A novel type of silver nanoparticles and their advantages in toxicity testing in cell culture systems N2 - 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. KW - Silver nanoparticles KW - Peptide coating KW - Nanotoxicity PY - 2012 U6 - https://doi.org/10.1007/s00204-012-0836-0 SN - 0340-5761 SN - 1432-0738 VL - 86 IS - 7 SP - 1089 EP - 1098 PB - Springer CY - Berlin ; Heidelberg [u.a.] AN - OPUS4-26269 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -