Structure and mechanism of the formation of core–shell nanoparticles obtained through a one-step gas-phase synthesis by electron beam evaporation

• Andrey V. Nomoev,
• Sergey P. Bardakhanov,
• Makoto Schreiber,
• Dashima G. Bazarova,
• Nikolai A. Romanov,
• Boris B. Baldanov,
• Bair R. Radnaev and
• Viacheslav V. Syzrantsev

Beilstein J. Nanotechnol. 2015, 6, 874–880, doi:10.3762/bjnano.6.89

• TEM micrograph of the synthesized Cu@silica nanoparticles is shown in Figure 1a. The average particle size was 119 ± 73 nm. A higher magnification image of the shell and core structure is shown in Figure 1b. In Figure 1b, it can clearly be seen that the shell structure is amorphous and much less dense

• .) spectrometer (130 eV energy resolution, 1 nm spatial resolution). To perform the measurements, the core–shell nanopowders were diluted in ethanol, subjected to ultrasonic dispersion, and precipitated onto a carbon film fixed to a copper grid. TEM micrograph of the Cu@silica nanoparticles. a) Overview, b

Pulmonary surfactant augments cytotoxicity of silica nanoparticles: Studies on an in vitro air–blood barrier model

• Jennifer Y. Kasper,
• Lisa Feiden,
• Maria I. Hermanns,
• Christoph Bantz,
• Michael Maskos,
• Ronald E. Unger and
• C. James Kirkpatrick

Beilstein J. Nanotechnol. 2015, 6, 517–528, doi:10.3762/bjnano.6.54

• . Thus, a prior interaction of NPs with pulmonary surfactant components will occur. In the present study we explored the impact of pulmonary surfactant on the cytotoxic potential of amorphous silica nanoparticles (aSNPs) using in vitro mono- and complex coculture models of the air–blood barrier

• culture period. Keywords: air–blood barrier; cytotoxicity; inflammatory response; pulmonary surfactant; silica nanoparticles; Introduction Biological barriers of the human body which directly interface the external environment have, besides their actual physiological function, the vital task of

• , phosphatidylglycerols) and up to 10% fatty acids, cholesterol and the crucial surfactant proteins A, B, C and D [5]. Subsequently, the immersion of NPs in the surfactant lining leads to a coating with surfactant components such as lipids or proteins [6]. It has already been shown for amorphous silica nanoparticles

Comparative evaluation of the impact on endothelial cells induced by different nanoparticle structures and functionalization

• Lisa Landgraf,
• Ines Müller,
• Peter Ernst,
• Miriam Schäfer,
• Christina Rosman,
• Isabel Schick,
• Oskar Köhler,
• Hartmut Oehring,
• Vladimir V. Breus,
• Thomas Basché,
• Carsten Sönnichsen,
• Wolfgang Tremel and
• Ingrid Hilger

Beilstein J. Nanotechnol. 2015, 6, 300–312, doi:10.3762/bjnano.6.28

• probably led to a higher uptake rate. Interestingly, Chen et al. observed a charge-dependent localization of mesoporous silica nanoparticles with positively charged particles in the cytosol and negatively charged ones in acidic endosomes [54]. Not only the surface coating but also the nanoparticle material

Overview about the localization of nanoparticles in tissue and cellular context by different imaging techniques

• Anja Ostrowski,
• Daniel Nordmeyer,
• Alexander Boreham,
• Cornelia Holzhausen,
• Lars Mundhenk,
• Christina Graf,
• Martina C. Meinke,
• Annika Vogt,
• Sabrina Hadam,
• Jürgen Lademann,
• Eckart Rühl,
• Ulrike Alexiev and
• Achim D. Gruber

Beilstein J. Nanotechnol. 2015, 6, 263–280, doi:10.3762/bjnano.6.25

• models following exposure with silica nanoparticles (SiO2-NP) [12][13][14]. Inorganic SiO2-NP hold great potential for several biomedical applications, including the selective targeting of cancer cells as well as drug or gene delivery systems due to their favorable biocompatibility and modification

• isothiocyanate (FITC) and indocarbocyanine. Several classes of NP have been localized after addition of such tags, including silica nanoparticles (SiO2-NP, Figure 3a) [28][75][79][80][81] and dPGS [82]. Inorganic SiO2-NP hold great potential for several biomedical applications, including the selective targeting

• for the detection of mixed QD populations with a single excitatory wavelength [86]. Furthermore, the impact of toxic ions released by QD on biological matter has been minimized by embedding QD into silica nanoparticles [88] without influencing the optical properties [89]. Unlike fluorescent dyes that

Intake of silica nanoparticles by giant lipid vesicles: influence of particle size and thermodynamic membrane state

• Florian G. Strobl,
• Florian Seitz,
• Christoph Westerhausen,
• Armin Reller,
• Adriano A. Torrano,
• Christoph Bräuchle,
• Achim Wixforth and
• Matthias F. Schneider

Beilstein J. Nanotechnol. 2014, 5, 2468–2478, doi:10.3762/bjnano.5.256

• present experiments on a massive uptake of silica nanoparticles by giant unilamellar lipid vesicles (GUVs). We find that this uptake process depends on the size of the particles as well as on the thermodynamic state of the lipid membrane. Our findings are discussed in the light of several theoretical

• attention so far is the mutual interplay of the adsorption behavior of nanoparticles and the phase state of membranes. In [29], for example, it was shown that the phase transition temperature of lipid membranes changes upon the interaction with silica nanoparticles. Our own research group recently found a

• about the interaction of silica nanoparticles in contact with giant unilamellar phospholipid vesicles (GUVs). In this simple system, all major steps of a particle uptake, as depicted in Figure 1 are found. It will be shown that this behavior is clearly dependent on the particle size and the phase state

Synthesis and characterization of fluorescence-labelled silica core-shell and noble metal-decorated ceria nanoparticles

• Rudolf Herrmann,
• Markus Rennhak and
• Armin Reller

Beilstein J. Nanotechnol. 2014, 5, 2413–2423, doi:10.3762/bjnano.5.251

• biological and medicinal investigations, and this was indeed confirmed in parallel toxicity studies with labelled and unlabelled silica [10][11] and titania [1] NP. Silica nanoparticles with a fluorescent polyorganosiloxane core Although the amount of fluorescent dye on the surface of the silica NP described

Interaction of dermatologically relevant nanoparticles with skin cells and skin

• Annika Vogt,
• Fiorenza Rancan,
• Sebastian Ahlberg,
• Berouz Nazemi,
• Chun Sik Choe,
• Maxim E. Darvin,
• Sabrina Hadam,
• Ulrike Blume-Peytavi,
• Kateryna Loza,
• Jörg Diendorf,
• Matthias Epple,
• Christina Graf,
• Eckart Rühl,
• Martina C. Meinke and
• Jürgen Lademann

Beilstein J. Nanotechnol. 2014, 5, 2363–2373, doi:10.3762/bjnano.5.245

• TEM images of HaCaT cells (obtained after incubation for 24 h with 25 µg/mL AgNP) AgNP are accumulated in endosomes (b–d). Uptake of fluorescent silica nanoparticles with variable size and surface functionalization by HaCaT cells. Different type of particles were prepared (a–d) with a size of 42 (a,c

Inorganic Janus particles for biomedical applications

• Isabel Schick,
• Steffen Lorenz,
• Dominik Gehrig,
• Stefan Tenzer,
• Wiebke Storck,
• Karl Fischer,
• Dennis Strand,
• Frédéric Laquai and
• Wolfgang Tremel

Beilstein J. Nanotechnol. 2014, 5, 2346–2362, doi:10.3762/bjnano.5.244

• the protein corona of silica nanoparticles. Moreover, no size-dependent particle-protein binding effect was observed while studying nanoparticles with a diameter of 125 nm, 20 nm, and 8 nm [114]. Introducing the anisotropy of Janus particles as another variable to the formation/analysis of the protein

Electrostatic interplay: The interaction triangle of polyamines, silicic acid, and phosphate studied through turbidity measurements, silicomolybdic acid test, and ²⁹Si NMR spectroscopy

• Anne Jantschke,
• Katrin Spinde and
• Eike Brunner

Beilstein J. Nanotechnol. 2014, 5, 2026–2035, doi:10.3762/bjnano.5.211

• of 5–7, more than 95% of the initial silicic acid are present in the form of insoluble silica. This is the result of the silica polycondensation reaction, which transforms soluble silica species into insoluble silica species, i.e., higher oligomers or silica nanoparticles. Such insoluble silica

• charged for pH > 9.8. Hence, purely electrostatic interactions between the polyamine and monosilicic acid cannot be expected. In contrast to monosilicic acid, higher silicic acid oligomers/silica nanoparticles exhibit lower pKa values. For fumed silica, two different types of silanol groups are reported

• with pKa values of ca. 8 and 4.5 [46][47]. It can therefore be assumed that, in the relevant pH range of 5–7, the silica nanoparticles exhibit a negative surface charge. Electrostatic interactions will, therefore, occur between the positively charged polyamine and negatively charged higher silicic acid

A reproducible number-based sizing method for pigment-grade titanium dioxide

• Ralf Theissmann,
• Manfred Kluwig and
• Thomas Koch

Beilstein J. Nanotechnol. 2014, 5, 1815–1822, doi:10.3762/bjnano.5.192

• of forthcoming national and international regulations concerning the classification of nanomaterials. Scientific efforts towards standardized number-based sizing methods have so far been concentrated on model systems, such as spherical gold or silica nanoparticles. However, for industrial particulate

The surface properties of nanoparticles determine the agglomeration state and the size of the particles under physiological conditions

• Christoph Bantz,
• Olga Koshkina,
• Thomas Lang,
• Hans-Joachim Galla,
• C. James Kirkpatrick,
• Roland H. Stauber and
• Michael Maskos

Beilstein J. Nanotechnol. 2014, 5, 1774–1786, doi:10.3762/bjnano.5.188

• characterization of two SiO2-based nanomaterials: silica nanoparticles that are electrostatically stabilized by negative surface charges and poly(organosiloxane) nanoparticles that were modified to carry positive charges and/or a polymer shell. We demonstrate a combination of carefully chosen characterization

• . Hence, they are highly suitable for tailored biomedical applications, for example, as drug carrier systems, as agents in hyperthermia, or as contrast agents for magnetic resonance imaging (MRI) [52][53]. Silica nanoparticles: As most of the common crystalline SiO2 particles are not in the nanometer-size

• region, we will focus on amorphous silica nanoparticles (aSNPs) in the following section. Based on their preparation procedure, aSNPs can be divided into three main subclasses [54]: 1. Silica sols (also called “colloidal silica”) are manufactured on the industrial scale by acidification of waterglass

Precise quantification of silica and ceria nanoparticle uptake revealed by 3D fluorescence microscopy

• Adriano A. Torrano and
• Christoph Bräuchle

Beilstein J. Nanotechnol. 2014, 5, 1616–1624, doi:10.3762/bjnano.5.173

• combines the advantages of confocal fluorescence microscopy with fast and precise semi-automatic image analysis. In this work we present how this method was applied to investigate the impact of 310 nm silica nanoparticles on human vascular endothelial cells (HUVEC) in comparison to a cancer cell line

• derived from the cervix carcinoma (HeLa). The absolute number of intracellular silica nanoparticles within the first 24 h was determined and shown to be cell type-dependent. As a second case study, Particle_in_Cell-3D was used to assess the uptake kinetics of 8 nm and 30 nm ceria nanoparticles interacting

• unusual uptake behavior could be cell division. Keywords: ceria nanoparticles; fluorescence microscopy; image analysis; nanotoxicology; silica nanoparticles; Introduction Measuring the interaction between nanoparticles and cells is a mandatory step for the investigation of nanoparticles designed for

Silica nanoparticles are less toxic to human lung cells when deposited at the air–liquid interface compared to conventional submerged exposure

• Alicja Panas,
• Andreas Comouth,
• Harald Saathoff,
• Thomas Leisner,
• Marco Al-Rawi,
• Michael Simon,
• Gunnar Seemann,
• Olaf Dössel,
• Sonja Mülhopt,
• Hanns-Rudolf Paur,
• Susanne Fritsch-Decker,
• Carsten Weiss and
• Silvia Diabaté

Beilstein J. Nanotechnol. 2014, 5, 1590–1602, doi:10.3762/bjnano.5.171

• higher by a factor of more than 20 compared to the unmodified VITROCELL deposition system. We studied two different amorphous silica nanoparticles (particles produced by flame synthesis and particles produced in suspension by the Stöber method). Aerosols with well-defined particle sizes and

• dependent on the exposure method. Keywords: aerosol; air–liquid interface; dose; silica nanoparticles; toxicity; Introduction Amorphous SiO2 nanoparticles (NPs) are regarded as only little pathogenic. However, it has been shown that the inhalation of silica NPs induces transient inflammation in rats [1][2

The protein corona protects against size- and dose-dependent toxicity of amorphous silica nanoparticles

• Dominic Docter,
• Christoph Bantz,
• Dana Westmeier,
• Hajo J. Galla,
• Qiangbin Wang,
• James C. Kirkpatrick,
• Peter Nielsen,
• Michael Maskos and
• Roland H. Stauber

Beilstein J. Nanotechnol. 2014, 5, 1380–1392, doi:10.3762/bjnano.5.151

• be resolved. Moreover, proteins associate with NP in physiological fluids, forming the protein corona potentially transforming the biological identity of the particle and thus, adding an additional level of complexity for the bio–nano responses. Here, we employed amorphous silica nanoparticles (ASP

• still not yet resolved [22]. Consequently, the presented study investigated the potential toxic effects of different amorphous silica NP (ASP), focusing on particle size and the relevance of the protein corona. Results Characterization of amorphous silica nanoparticles (ASP) A comprehensive

• , the GI tract also contains additional biobarriers, such as mucous matrices and other biomolecules. Thus, future studies need to consider experimentally this layer of additional complexity to resolve the mechanisms and (patho)biological effects of silica nanoparticles in vitro and in vivo. Generally

Organic and inorganic–organic thin film structures by molecular layer deposition: A review

• Pia Sundberg and
• Maarit Karppinen

Beilstein J. Nanotechnol. 2014, 5, 1104–1136, doi:10.3762/bjnano.5.123

• using 1,4-diisothiocyanatobenzene and ED as the precursors (Table 8). The deposition temperature in these experiments was kept at 50 °C and the films were grown on silicon and silica nanoparticles. The obtained growth rates were 1.9 and 2.8 Å per cycle, respectively. These values are modest when

Biocalcite, a multifunctional inorganic polymer: Building block for calcareous sponge spicules and bioseed for the synthesis of calcium phosphate-based bone

• Xiaohong Wang,
• Heinz C. Schröder and
• Werner E. G. Müller

Beilstein J. Nanotechnol. 2014, 5, 610–621, doi:10.3762/bjnano.5.72

• 2:1, while in S. domuncula the molar ratio amounts to 4:1. Soon after the expression of the silicateins and after the first formation of silica nanoparticles, the silicatein-interacting proteins, the silintaphins, are read out (Figure 1A). Until now two silintaphins, silintaphin-1 [12] and

Structural, optical and photocatalytic properties of flower-like ZnO nanostructures prepared by a facile wet chemical method

• Sini Kuriakose,
• Neha Bhardwaj,
• Jaspal Singh,
• Biswarup Satpati and
• Satyabrata Mohapatra

Beilstein J. Nanotechnol. 2013, 4, 763–770, doi:10.3762/bjnano.4.87

• ] by the tape casting method. These ZnO plates showed a good photocatalytic activity for azo dyes that depended on their surface area. Shen et al. [34] have shown that depositing ZnO on silica nanoparticles is a simple and effective method to prepare photocatalysts that could degrade 90% methylene blue

Effect of spherical Au nanoparticles on nanofriction and wear reduction in dry and liquid environments

• Dave Maharaj and
• Bharat Bhushan

Beilstein J. Nanotechnol. 2012, 3, 759–772, doi:10.3762/bjnano.3.85

• include, but are not limited to, their use in targeted drug delivery and chemical sensors in the identification of oil, removal of contaminants and enhanced oil recovery (EOR). Au, iron oxide, polymer and silica nanoparticles have been studied in targeted drug delivery [3][4][5][6][7][8]. In cancer

Pore structure and surface area of silica SBA-15: influence of washing and scale-up

• Jörg P. Thielemann,
• Frank Girgsdies,
• Robert Schlögl and
• Christian Hess

Beilstein J. Nanotechnol. 2011, 2, 110–118, doi:10.3762/bjnano.2.13

• Silica (PHTS), which is a material analogous to SBA-15, synthesized at different TEOS/Pluronic 123 ratios, the occurrence of pore narrowing and blocking by silica nanoparticles inside the pores [25][32][33][34]. Tian et al. polymerized N-isopropylacrylamide inside the SBA-15 structure and explained their