title: Interaction of differently functionalized fluorescent silica nanoparticles with neural stem- and tissue-type cells.
abstract: Engineered amorphous silica nanoparticles (SiO2 NPs), due to simple and low cost production, are increasingly used in commercial products and produced on an industrial scale. Despite the potential benefits, there is a concern that exposure to certain types of SiO2 NPs may lead to adverse health effects. As some NPs can cross the blood--brain barrier and may, in addition, reach the central nervous system through the nasal epithelium, this study addresses the responses of different neural tissue-type cells including neural stem cells, neurons, astrocytes and microglia cells to increasing doses of 50 nm fluorescent core/shell SiO2 NPs with different [-NH2, -SH and polyvinylpyrrolidone (PVP)] surface chemistry. The SiO2 NPs are characterized using a variety of physicochemical methods. Assays of cytotoxicity and cellular metabolism indicates that SiO2 NPs cause cell death only at high particle doses, except PVP-coated SiO2 NPs which do not harm cells even at very high concentrations. All SiO2 NPs, except those coated with PVP, form large agglomerates in physiological solutions and adsorb a variety of proteins. Except PVP-NPs, all SiO2 NPs adhere strongly to cell surfaces, but internalization differs depending on neural cell type. Neural stem cells and astrocytes internalize plain SiO2, SiO2-NH2 and SiO2-SH NPs, while neurons do not take up any NPs. The data indicates that the PVP coat, by lowering the particle-biomolecular component interactions, reduces the biological effects of SiO2 NPs on the investigated neural cells.
authors.affiliation: Bayer Technology Services GmbH , Leverkusen , Germany .
authors.forename: Emilia
authors.initials: E
authors.lastname: Izak-Nau
authors.forename: Kata
authors.initials: K
authors.lastname: Kenesei
authors.forename: Kumarasamy
authors.initials: K
authors.lastname: Murali
authors.forename: Matthias
authors.initials: M
authors.lastname: Voetz
authors.forename: Stefanie
authors.initials: S
authors.lastname: Eiden
authors.forename: Victor F
authors.initials: VF
authors.lastname: Puntes
authors.forename: Albert
authors.initials: A
authors.lastname: Duschl
authors.forename: Emilia
authors.initials: E
authors.lastname: Madarász
mesh_terms: D002460:Cell Line; D005456:Fluorescent Dyes / Q000737:chemistry*; D006801:Humans; D008854:Microscopy, Electron; D053758:Nanoparticles; D058953:Neural Stem Cells / Q000166:cytology*; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D005456:Fluorescent Dyes; D012822:Silicon Dioxide
keywords: Fluorescence spectrum analysis; neural cell types; silica NP; toxicity; uptake