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

• by the manufacturer micromod GmbH). aSNP–NH2 retained a negative “netto” surface charge according to their zeta potential, although it is supposed to display a positive charge on the basis of the amino-groups. This phenomenon was already described by Tenzer et al., who concluded that according to the

• zeta potential the functionalization of similar aSNPs with amino groups was not saturated so as to mask negative charge of the surface silanols [38]. In terms of chemistry aSNP–NH2 and –COOH have remaining silanol groups to a similar extent. Since aSNP–COOH (with a similar amount of free silanol groups

• compared to aSNP–NH2) did not cause a toxic effect at 100 µg/mL this indicates that amino groups may also be able to interact with lung surfactant and hereby augment cytotoxicity. With respect to possible mechanisms, the interaction of the silanol groups of aSNP–plain with lung surfactant might initiate

Synthesis of boron nitride nanotubes and their applications

• Saban Kalay,
• Zehra Yilmaz,
• Ozlem Sen,
• Melis Emanet,
• Emine Kazanc and
• Mustafa Çulha

Beilstein J. Nanotechnol. 2015, 6, 84–102, doi:10.3762/bjnano.6.9

• amino groups and its use as a good dispersion agent [79]. The BNNTs were first coated with PLL and then with quantum dots (QDs) to observe the cellular uptake of PLL–BNNTs in C2C12 mouse myoblast cells. To observe the energy dependence of the uptake mechanism of the PLL–BNNTs, sodium azide was used to

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

• [15][16][17][18][19][20] including iridium complexes [21]. The presence of amino groups after the attachment of APS to silica can be used for an alternative approach to NP similar to our MPD-labelled NP by reaction with perylenetetracarboxylic acid monoanhydrides [22], or for the reaction of other

Functionalized polystyrene nanoparticles as a platform for studying bio–nano interactions

• Cornelia Loos,
• Tatiana Syrovets,
• Anna Musyanovych,
• Volker Mailänder,
• Katharina Landfester,
• G. Ulrich Nienhaus and
• Thomas Simmet

Beilstein J. Nanotechnol. 2014, 5, 2403–2412, doi:10.3762/bjnano.5.250

• used superparamagnetic iron oxide nanoparticles. Keywords: amino groups; apoptosis; carboxyl groups; cell proliferation; leukemia cell lines; macrophages; mTOR; polystyrene nanoparticles; Review Applications of polystyrene Polystyrene, one of the most extensively used types of plastic [1], is an

• show signs of apoptosis at this time point [41]. These data are in agreement with the previously proposed ‘‘proton-sponge’’ hypothesis, which refers to a continuous activation of the lysosomal proton pump, lysosomal swelling and rupture by particles carrying amino groups on their surface [20][41][50

• ][51]. Similarly, amino-terminated dendrimers have been shown to induce holes in biological membranes [52][53]. Interestingly, the degree of toxicity of such particles is proportional to the amount of amino groups on the particle surface [54] and is inversely dependent on the particle size: smaller

Nanoparticle interactions with live cells: Quantitative fluorescence microscopy of nanoparticle size effects

• Li Shang,
• Karin Nienhaus,
• Xiue Jiang,
• Linxiao Yang,
• Katharina Landfester,
• Volker Mailänder,
• Thomas Simmet and
• G. Ulrich Nienhaus

Beilstein J. Nanotechnol. 2014, 5, 2388–2397, doi:10.3762/bjnano.5.248

• essentially the same size and surface charge, namely plain, CTMA-stabilized PS+ NPs and amino-functionalized PS NPs (NPS NPs) carrying about 6,000 amino groups on their surfaces (Table 1) [33]. This study was further extended to include the effect of surface carboxyl groups on the interaction of anionic NPs

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

• functionalization of silica particles with amino groups in order to turn the surface potential of the particles from initially negative to highly positive did not significantly affect cellular uptake rates in whole-tissue experiments. However, immortalized human keratinocytes (HaCaT, Human Adult Low Calcium High

• heavily aggregated but still taken up into cells in large numbers. However, N-(6-aminohexyl)-aminopropyltrimethoxysilane (AHAPS)-functionalized particles, which had also a highly positive zeta-potential due to the amino groups but did not aggregate in cell culture media were also found in large numbers in

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

• introducing amino-groups at the surface [108][109]. The resulting positively charged nanoparticles are known to be taken up more efficiently in in vitro cultures [110][111], whereby amine-functionalized silica-particles enable covalent conjugation of dyes, biomolecules, such as sugars, antibodies, and

Liquid-phase exfoliated graphene: functionalization, characterization, and applications

• Mildred Quintana,
• Jesús Iván Tapia and
• Maurizio Prato

Beilstein J. Nanotechnol. 2014, 5, 2328–2338, doi:10.3762/bjnano.5.242

• cycloaddition, performed on graphene by employing an aldehyde and an α-amino acid as precursors, attacks both graphene faces and edges. This reactivity was observed by introducing protonated terminal amino groups that selectively bind gold nanorods allowing the recognition of the reactive sites by low

Nanoencapsulation of ultra-small superparamagnetic particles of iron oxide into human serum albumin nanoparticles

• Matthias G. Wacker,
• Mahmut Altinok,
• Stephan Urfels and
• Johann Bauer

Beilstein J. Nanotechnol. 2014, 5, 2259–2266, doi:10.3762/bjnano.5.235

• observations in TEM HSA nanoparticles were chemically stabilized by using the theoretical amount of glutaraldehyde corresponding to a crosslinking of 100% of the 60 amino groups in the HSA molecule. By this, HSA nanoparticles with transparent appearance (grey) in the TEM were generated. Iron core particles of

• ethanol at a rate of 1.5 mL/min under permanent stirring (550 rpm). Afterwards, a volume of aqueous glutaraldehyde solution 8% [v/v] corresponding to between 100% and 600% of stoichiometric crosslinking of the amino groups in 50 mg HSA was added to stabilize the resulting protein nanoparticles. Particles

• USPIO HSA hybrid particles with an USPIO load of 30 µg/mg and crosslinked with a volume of glutaraldehyde corresponding to a 100% of the amino groups of the HSA molecule were used. All samples were applied to copper grids with a carbon-coated Pioloform film and dried overnight at room temperature. The

Influence of stabilising agents and pH on the size of SnO₂ nanoparticles

• Olga Rac,
• Patrycja Suchorska-Woźniak,
• Marta Fiedot and
• Helena Teterycz

Beilstein J. Nanotechnol. 2014, 5, 2192–2201, doi:10.3762/bjnano.5.228

• be present in the form of molecules with different degrees of branching and molecular weight varying over a wide range. With regard to structure, in its linear form, it contains secondary amino groups, and in its branched form, primary, secondary and tertiary amino groups are present [22]. PEI is a

Biopolymer colloids for controlling and templating inorganic synthesis

• Laura C. Preiss,
• Katharina Landfester and
• Rafael Muñoz-Espí

Beilstein J. Nanotechnol. 2014, 5, 2129–2138, doi:10.3762/bjnano.5.222

• templates: Biomacromolecules contain often functional groups (such as phosphates in DNA or carboxylic and amino groups in proteins) that are able to complex metal ions and act as nucleation centers for the growth of metal or mineral nanoparticles. The use of molecular templates as a support for inorganic

Modification of a single-molecule AFM probe with highly defined surface functionality

• Fei Long,
• Bin Cao,
• Ashok Khanal,
• Shiyue Fang and
• Reza Shahbazian-Yassar

Beilstein J. Nanotechnol. 2014, 5, 2122–2128, doi:10.3762/bjnano.5.221

• 1.1–1.5, respectively, for the silicon probe, and 95 ± 64 pN, 111 ± 33 pN, and 3.5–4.4, respectively, for the Au-coated probe. Both probes had similar values of Fi, showing the same nature of the specific hydrogen bond interaction between the carboxylic acid groups on the probe and amino groups on the

• . The PEG molecules on the glass surface had different lateral distances to the tip, and the terminal amino groups had an equal probability to interact with the carboxylic groups on the probe. Therefore, a uniform distribution was expected in the histogram of the probe–sample separation at which

• from Thermo Scientific. All other chemicals including isopropanol are of reagent grade from Sigma-Aldrich. AFM experiments were carried out on a Bruker Dimension ICON AFM system. Preparation of AFM probes Amino-functionalization of Si probes: Si probes were functionalized with amino groups according to

Sequence-dependent electrical response of ssDNA-decorated carbon nanotube, field-effect transistors to dopamine

• Hari Krishna Salila Vijayalal Mohan,
• Jianing An and
• Lianxi Zheng

Beilstein J. Nanotechnol. 2014, 5, 2113–2121, doi:10.3762/bjnano.5.220

• transistor parameters for DA detection compared to bases G and A [41]. Another possibility capable of enhancing the response of ssDNA-containing bases G and A to DA is the unbound interaction known as the edge-to-face NH–π interaction [37][42]. This occurs between the hydrogen of the amino groups of these

Effects of surface functionalization on the adsorption of human serum albumin onto nanoparticles – a fluorescence correlation spectroscopy study

• Pauline Maffre,
• Stefan Brandholt,
• Karin Nienhaus,
• Li Shang,
• Wolfgang J. Parak and
• G. Ulrich Nienhaus

Beilstein J. Nanotechnol. 2014, 5, 2036–2047, doi:10.3762/bjnano.5.212

• DPA amino groups on the QD. This is a most interesting finding in the light of the protein adsorption resistance and non-fouling properties that are usually attributed to zwitterionic surfaces [51]. Our data would suggest that these properties may derive from binding a single layer of proteins, which

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

• ]. They consist of linear oligo-propyleneimine chains attached to putrescine or spermine [5][6]. Biosilica-associated LCPAs occur either as free molecules [1][4] or covalently attached to the ε-amino groups of certain lysine-residues [7][8] in highly post-translationally modified peptides, so-called

In vitro and in vivo interactions of selected nanoparticles with rodent serum proteins and their consequences in biokinetics

• Wolfgang G. Kreyling,
• Stefanie Fertsch-Gapp,
• Martin Schäffler,
• Blair D. Johnston,
• Nadine Haberl,
• Christian Pfeiffer,
• Jörg Diendorf,
• Carsten Schleh,
• Stephanie Hirn,
• Manuela Semmler-Behnke,
• Matthias Epple and
• Wolfgang J. Parak

Beilstein J. Nanotechnol. 2014, 5, 1699–1711, doi:10.3762/bjnano.5.180

• ; details are given in [5]. We chose nano-sized and submicrometer-sized carbon black versus 50 nm monodisperse polystyrene NP with surface modifications of either carboxyl groups (negative charge), or amino groups (positive charge) or plain surface (neutral charge) as measured by their zeta potential and

• three routes: intratracheal instillation into the lungs, intravenous injection into blood and intra-esophageal instillation into the gastro-intestinal tract. The AuNP were synthesized and surface-modified not only with small ionic ligands such as sulfonated triphenylphosphine, amino groups, or carboxyl

• supernatant after BSA separation from the 50 nm Polystyrene (PS) NP–protein complexes (PS-Plain: neutral charge, PS-COOH: negative charge by carboxyl groups, PS-NH2: positive charge by amino groups) depending on the NP dose; the error bars show the standard deviation). Each line represents the linear

Near-field photochemical and radiation-induced chemical fabrication of nanopatterns of a self-assembled silane monolayer

• Ulrich C. Fischer,
• Carsten Hentschel,
• Florian Fontein,
• Linda Stegemann,
• Christiane Hoeppener,
• Harald Fuchs and
• Stefanie Hoeppener

Beilstein J. Nanotechnol. 2014, 5, 1441–1449, doi:10.3762/bjnano.5.156

• plasma or UV–ozone processing [26]. In process 2, oxygen-plasma induced nanostructuring, an oxygen plasma leads primarily to the chemical destruction of the amino groups of an (3-aminopropyl)triethoxysilane (APTES) SAM. For this process the close contact between mask and the very thin SAM substrate is

• mixture of a radiation-induced chemical and a near-field photochemical process. In this case, the formation of the highly reactive ozone species and photochemical reactions result in a destruction of the amino groups of an APTES SAM. Common basis for all three structuring strategies is a metallic mask

• binding of the fluorescein tags to the amino groups of the APTES SAM. A fluorescence image of the 1.2 µm nanopattern was found (Figure 3b). Clearly the hexagonally aligned triangular fluorescence pattern is observed. Additional experiments included the labeling of the fabricated chemical nanopatterns with

Energy transfer in complexes of water-soluble quantum dots and chlorin e6 molecules in different environments

• Irina V. Martynenko,
• Anna O. Orlova,
• Vladimir G. Maslov,
• Alexander V. Baranov,
• Anatoly V. Fedorov and
• Mikhail Artemyev

Beilstein J. Nanotechnol. 2013, 4, 895–902, doi:10.3762/bjnano.4.101

• -terminated polyethylene glycol (PEG-OH)thiol and amino-terminated polyethylene glycol (PEG-NH2)thiol with a ratio of 3 to 1. This enables to obtain stable colloidal solutions of quantum dots. Then the covalent binding of the QD surface amino groups with the Ce6 carboxyl functional groups using EDAC as a

• the membrane and those of the Ce6. We replaced the carboxyl groups on the pore walls by amino groups with EDAC similar as described in [12]. This made it possible to create membranes with positive charges on the pore walls and to embed Ce6 molecules into membranes. Estimations of the FRET efficiency

Selective surface modification of lithographic silicon oxide nanostructures by organofunctional silanes

• Thomas Baumgärtel,
• Christian von Borczyskowski and
• Harald Graaf

Beilstein J. Nanotechnol. 2013, 4, 218–226, doi:10.3762/bjnano.4.22

• this may be a hint that either the APTES monolayer is not closed on a nanoscopic scale or the molecules in the monolayer are not well-ordered. The latter would lead to a rather low density of surface amino groups [39] that are available for reaction with the functional group of FITC. However, the next

• -neighbor distance between two adjacent surface amino groups must be below the AFM tip diameter (≈30 nm) as no distinct height steps or islands could be observed in the AFM images. A resolution of the density of bound molecules may be possible by using novel techniques such as the measurement of AFM

Directed deposition of silicon nanowires using neopentasilane as precursor and gold as catalyst

• Britta Kämpken,
• Verena Wulf,
• Norbert Auner,
• Marcel Winhold,
• Michael Huth,
• Daniel Rhinow and
• Andreas Terfort

Beilstein J. Nanotechnol. 2012, 3, 535–545, doi:10.3762/bjnano.3.62

• nanoparticles with a size of 60 nm were synthesized by following standard protocols [42] and deposited from solution onto Si[111] substrates. For this, the native oxide layer of the silicon wafers was modified by a monolayer of 3-aminopropyl-terminated siloxane [43], the amino groups of which are able to

FTIR nanobiosensors for Escherichia coli detection

• Stefania Mura,
• Gianfranco Greppi,
• Maria Laura Marongiu,
• Pier Paolo Roggero,
• Sandeep P. Ravindranath,
• Lisa J. Mauer,
• Nicoletta Schibeci,
• Francesco Perria,
• Massimo Piccinini,
• Plinio Innocenzi and
• Joseph Irudayaraj

Beilstein J. Nanotechnol. 2012, 3, 485–492, doi:10.3762/bjnano.3.55

• our group [26]. Film functionalization The optimization of the functionalization with amino-groups was obtained by immersing the calcined films in a solution 0.2 M of APTES in toluene for 24 h at 25 °C. The amino grafted films were carefully washed with toluene over several washing cycles and finally

• antibodies due to the formation of an imine. Here, the terminal amino groups of APTES were changed to aldehydic groups that, in the following step, were covalently coupled with the amino groups of the antibody. The APTES–GA linking is shown in Figure 2b, in which the bands due to the formation of imines in

Influence of water on the properties of an Au/Mpy/Pd metal/molecule/metal junction

• Jan Kučera and
• Axel Groß

Beilstein J. Nanotechnol. 2011, 2, 384–393, doi:10.3762/bjnano.2.44

• molecules, periodic density functional theory (DFT) calculations of the bare Au/ATP/Pd junction, assuming a () structure of the ATP molecules, were able to reproduce the experimentally observed downshift of the Pd DOS reasonably well [2][12] under the assumption that the amino groups of the ATP molecules

Microfluidic anodization of aluminum films for the fabrication of nanoporous lipid bilayer support structures

• Jaydeep Bhattacharya,
• Alexandre Kisner,
• Andreas Offenhäusser and
• Bernhard Wolfrum

Beilstein J. Nanotechnol. 2011, 2, 104–109, doi:10.3762/bjnano.2.12

• . Vesicle rupture is probably aided via electrostatic interactions of the negative phosphate of the zwitterionic POPC-heads with the protonated amino groups from the APTES molecules immobilized on the surface [42]. In principle, one could also expect coverage of the inside pore walls, as has been observed