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 -