Silica nanoparticles for intracellular protein delivery: A novel synthesis approach using green fluorescent protein

In this study, a novel approach for preparation of green fluorescent protein (GFP)-doped silica nanoparticles with a narrow size distribution is presented. GFP was chosen as a model protein due to its autofluorescence. Protein-doped nanoparticles have a high application potential in the field of intracellular protein delivery. In addition, fluorescently labelled particles can be used for bioimaging. The size of these protein-doped nanoparticles was adjusted from 15 to 35 nm using a multistep synthesis process, comprising the particle core synthesis followed by shell regrowth steps. GFP was selectively incorporated into the silica matrix of either the core or the shell or both by a one-pot reaction. The obtained nanoparticles were characterised by determination of particle size, hydrodynamic diameter, ζ-potential, fluorescence and quantum yield. The measurements showed that the fluorescence of GFP was maintained during particle synthesis. Cellular uptake experiments demonstrated that the GFP-doped nanoparticles can be used as stable and effective fluorescent probes. The study reveals the potential of the chosen approach for incorporation of functional biological macromolecules into silica nanoparticles, which opens novel application fields like intracellular protein delivery

Popularization of health in public television: the case of RTVE in 2016

La televisión es el principal medio al que los ciudadanos están expuestos para informarse sobre temas de ciencia y tecnología (FECYT, 2015). El servicio pú- blico radiotelevisivo es el ente, que, por ley, debe atender a las necesidades de información, cultura, educación y entretenimiento de la ciudadanía. Esta investigación tiene como objetivo conocer el tratamiento informativo y audiovisual de los programas especializados en salud de RTVE. La muestra cuenta con aquellos emitidos en 2016: La mañana (incluye Saber Vivir), Centro Médico, Esto es Vida y El Ojo Clínico. La metodología empleada es el estudio de caso: se elabora una triangulación a partir de una exploración descriptivo-analítica de los programas seleccionados, un cuestionario sobre la recepción informativa de los mismos y un análisis de contenido de una serie de episodios y, a su vez, de los tweets emitidos por sus respectivas cuentas durante el último mes. Las variables miden aspectos del tratamiento informativo y audiovisual de los programas, así como la funcionalidad, el tratamiento informativo de los tuits y el contenido extra que aportan. Los resultados presentan como rasgo común la conducción de la información a través de fuentes personales. Asimismo, destaca El Ojo Clínico y Esto es Vida por su tratamiento divulgativo, tanto en pantalla como en Twitter.Citizens inform themselves about science and technology mainly through television (FECYT, 2015) and the public broadcasting service is the entity that by law must offer the information, culture, education and entertainment that citizens need. This research aims to know the informative and audiovisual treatment of RTVE’s specialized health programs. The sample consists of the programmes broadcasted in 2016: La mañana (includes Saber Vivir), Centro Médico, Esto es Vida and El Ojo Clínico. A case study methodology will be implemented, a triangulation of methods is applied: a descriptive-analytical exploration of the selected programs, a content analysis of some episodes and of a sample of official tweets issued by the tv programmes accounts and a questionnaire on the informative reception by the audience. The variables analyse aspects of the informative and audiovisual treatment of the tv programmes, as well as tweet’s aims and reporting style. An overall result is the common usage of personal information as scientific sources. El Ojo Clínico and Esto es Vida need to be highlighted for their positive informative reporting, both on screen and on Twitter

Stereochemically Pure Si‐Chiral Aminochlorosilanes

Silicon-based compounds with stereochemical information and convertible functional units are valuable building blocks in synthetic chemistry. Si-stereogenic aminochlorosilanes are built up by Si−N bond formation between an achiral dichlorosilane and a chiral enantiomerically pure primary amine. Both diastereomers could be isolated as stereochemically pure single-crystals by fractional crystallization and were analyzed by X-ray crystallography. Defined intermolecular interaction patterns were identified illustrating the role of N−H⋅⋅⋅π, C−H⋅⋅⋅π, and N−H⋅⋅⋅Cl contacts in the molecular crystalline packing arrangements. Stepwise functionalization of the silicon−chlorine and silicon−amine functions was carried out, demonstrating their potential for use as a chiral synthesis precursors. Via optically pure aminomethoxysilanes, enantiomerically enriched methoxysilanols, chloromethoxysilanes, and methoxysilanethiols were synthesized. The stereospecificity of the transformations was monitored. The (R)-BINOL-PSSLi method for determining the enantiomeric purity was found to be the tool of choice for acid-sensitive silanols and silanethiols

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Silica Nanoparticles for Intracellular Protein Delivery: a Novel Synthesis Approach Using Green Fluorescent Protein

In this study, a novel approach for preparation of green fluorescent protein (GFP)-doped silica nanoparticles with a narrow size distribution is presented. GFP was chosen as a model protein due to its autofluorescence. Protein-doped nanoparticles have a high application potential in the field of intracellular protein delivery. In addition, fluorescently labelled particles can be used for bioimaging. The size of these protein-doped nanoparticles was adjusted from 15 to 35 nm using a multistep synthesis process, comprising the particle core synthesis followed by shell regrowth steps. GFP was selectively incorporated into the silica matrix of either the core or the shell or both by a one-pot reaction. The obtained nanoparticles were characterised by determination of particle size, hydrodynamic diameter, ζ-potential, fluorescence and quantum yield. The measurements showed that the fluorescence of GFP was maintained during particle synthesis. Cellular uptake experiments demonstrated that the GFP-doped nanoparticles can be used as stable and effective fluorescent probes. The study reveals the potential of the chosen approach for incorporation of functional biological macromolecules into silica nanoparticles, which opens novel application fields like intracellular protein delivery

Non-Canonical Activation of the Epidermal Growth Factor Receptor by Carbon Nanoparticles

The epidermal growth factor receptor (EGFR) is an abundant membrane protein, which is essential for regulating many cellular processes including cell proliferation. In our earlier studies, we observed an activation of the EGFR and subsequent signaling events after the exposure of epithelial cells to carbon nanoparticles. In the current study, we describe molecular mechanisms that allow for discriminating carbon nanoparticle-specific from ligand-dependent receptor activation. Caveolin-1 is a key player that co-localizes with the EGFR upon receptor activation by carbon nanoparticles. This specific process mediated by nanoparticle-induced reactive oxygen species and the accumulation of ceramides in the plasma membrane is not triggered when cells are exposed to non-nano carbon particles or the physiological ligand EGF. The role of caveolae formation was demonstrated by the induction of higher order structures of caveolin-1 and by the inhibition of caveolae formation. Using an in vivo model with genetically modified mice lacking caveolin-1, it was possible to demonstrate that carbon nanoparticles in vivo trigger EGFR downstream signaling cascades via caveolin-1. The identified molecular mechanisms are, therefore, of toxicological relevance for inhaled nanoparticles. However, nanoparticles that are intentionally applied to humans might cause side effects depending on this phenomenon

Non-Canonical Activation of the Epidermal Growth Factor Receptor by Carbon Nanoparticles

The epidermal growth factor receptor (EGFR) is an abundant membrane protein, which is essential for regulating many cellular processes including cell proliferation. In our earlier studies, we observed an activation of the EGFR and subsequent signaling events after the exposure of epithelial cells to carbon nanoparticles. In the current study, we describe molecular mechanisms that allow for discriminating carbon nanoparticle-specific from ligand-dependent receptor activation. Caveolin-1 is a key player that co-localizes with the EGFR upon receptor activation by carbon nanoparticles. This specific process mediated by nanoparticle-induced reactive oxygen species and the accumulation of ceramides in the plasma membrane is not triggered when cells are exposed to non-nano carbon particles or the physiological ligand EGF. The role of caveolae formation was demonstrated by the induction of higher order structures of caveolin-1 and by the inhibition of caveolae formation. Using an in vivo model with genetically modified mice lacking caveolin-1, it was possible to demonstrate that carbon nanoparticles in vivo trigger EGFR downstream signaling cascades via caveolin-1. The identified molecular mechanisms are, therefore, of toxicological relevance for inhaled nanoparticles. However, nanoparticles that are intentionally applied to humans might cause side effects depending on this phenomenon

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Additional file 8: Figure S8. of Silica Nanoparticles for Intracellular Protein Delivery: a Novel Synthesis Approach Using Green Fluorescent Protein

AUC spectra of the GFP modified silica nanoparticles (CFS1FS2F) and unlabelled silica nanoparticles mixed with GFP (CUS1US2U). Same amounts of particles and GFP were used. In all spectra, the absorption was plotted against the radial position (cm). To detect the sedimentation velocity of silica nanoparticles, a wavelength of 261 nm was chosen, whereas a wavelength of 488 nm was used for the GFP detection. In A and B the sedimentation of GFP-labelled particles is shown and in C and D the sedimentation of unlabelled silica nanoparticles with additional added GFP. (TIFF 8201 kb