Uptake and intracellular accumulation of diamond nanoparticles – a metabolic and cytotoxic study

• Antonín Brož,
• Lucie Bačáková,
• Pavla Štenclová,
• Alexander Kromka and
• Štěpán Potocký

Beilstein J. Nanotechnol. 2017, 8, 1649–1657, doi:10.3762/bjnano.8.165

• ][27], particle size reduction [22] and surface oxidation (i.e., the surface is covered by defined starting functional groups). The cytotoxicity of NDs depends on their origin (i.e., DNDs or HPHT NDs), their size (distribution), their tendency to form aggregates (surface charge), the presence of

• their zeta potential, which influences the aggregation or the selection of adhered proteins from the culture medium. The as-received DNDs have a strongly positive zeta potential of ≈40 mV, while oxidation reverses it to approximately −40 mV [41]. The cell surface charge is influenced by the actual

• biochemical composition of the cytoplasmic membrane and the state of the cell. It is an important biophysical parameter influencing the interaction with the cell surroundings. The cell surface charge (zeta potential) of human cells was between −20 and −30 mV caused by the presence of nonionogenic groups

The effect of the electrical double layer on hydrodynamic lubrication: a non-monotonic trend with increasing zeta potential

• Dalei Jing,
• Yunlu Pan and
• Xiaoming Wang

Beilstein J. Nanotechnol. 2017, 8, 1515–1522, doi:10.3762/bjnano.8.152

• of charged frictional pair–lubricant interface and the resulting electrical double layer (EDL) within the lubricant have been recognized and studied [5][6][7][8][9][10][11][12][13]. The generation of surface charge at the frictional pair–lubricant interface is wide, especially for the frictional

• lubrication theory have a history dating back to hundreds of years, the role of surface-charge-induced EDL on the lubrication is a relatively new field. This role was first considered for the study of thin film lubrication by Bike and Prieve [6]. Following them, Zhang and Umehara [7] introduced the effect of

• the EDL on modifying the conventional Reynolds equation, analyzing the hydrodynamic lubrication. They found that the minimum lubricant film thickness increased with the increasing absolute value of zeta potential (an important parameter of EDL to manifest the surface charge at the solid–liquid

Development of polycationic amphiphilic cyclodextrin nanoparticles for anticancer drug delivery

• Gamze Varan,
• Juan M. Benito,
• Carmen Ortiz Mellet and
• Erem Bilensoy

Beilstein J. Nanotechnol. 2017, 8, 1457–1468, doi:10.3762/bjnano.8.145

• derivatives provide suitable nanometer-sized drug delivery systems for safe and efficient intravenous paclitaxel delivery for chemotherapy. In the light of these studies, it can be said that amphiphilic cyclodextrin nanoparticles of different surface charge can be considered as a promising alternative for

• several factors that influence the particle size, particle distribution, surface charge, homogeneity and shape of nanometer-sized drug delivery systems. These factors have a subsequent influence on the biodistribution and the fate of the nanomedicine in the body [27]. In this case, the formulation

• of the polymer/polysaccharide used to prepare the nanoparticles. Therefore, in order to determine the effect of surface charge on drug loading capacity of nanoparticles, PCX was chosen as a model anticancer drug frequently used in chemotherapy for patients with breast cancer. The encapsulation

Cationic PEGylated polycaprolactone nanoparticles carrying post-operation docetaxel for glioma treatment

• Cem Varan and
• Erem Bilensoy

Beilstein J. Nanotechnol. 2017, 8, 1446–1456, doi:10.3762/bjnano.8.144

• than 100 nm and a net positive surface charge to facilitate cellular internalization of drug-loaded nanoparticles. Hydroxypropyl cellulose films were prepared to incorporate these nanoparticle dispersions to complete the implantable drug delivery system. Results: The diameter of core–shell

• nanoparticles were in the range of 70–270 nm, depending on the preparation technique, polymer type and coating. Moreover, the chitosan coating significantly altered the surface charge of the nanoparticles to net positive values of +30 to +50 mV. The model drug docetaxel was successfully loaded into all

• particles (which have neutral or near-neutral surface charge) are more prone to escape from the MPS. Cationic nanoparticles can also condense nucleic acid (DNA, RNA) or proteins to form polyplexes for intracellular gene/drug delivery. In this context, chitosan (CS) is used as a positively charged coating

Evaluation of quantum dot conjugated antibodies for immunofluorescent labelling of cellular targets

• Jennifer E. Francis,
• David Mason and
• Raphaël Lévy

Beilstein J. Nanotechnol. 2017, 8, 1238–1249, doi:10.3762/bjnano.8.125

• between Qdots and functional antibodies, the overall surface charge of Qdot-Ab conjugates, and whether there is a presence of a protein corona. The labelling ratio of Qdots to antibodies present within commercially available Qdot-Ab conjugates has been previously evaluated, where the non-specific

• orientation in which the IgG molecules bind to Qdots cannot be controlled [37]. The binding affinity of Qdot-Abs can also be affected by the surface charge they possess. For instance, positively charged Qdots are taken up by cells more readily than negatively charged or zwitterionic Qdots, which suppress

Needs and challenges for assessing the environmental impacts of engineered nanomaterials (ENMs)

• Michelle Romero-Franco,
• Hilary A. Godwin,
• Muhammad Bilal and
• Yoram Cohen

Beilstein J. Nanotechnol. 2017, 8, 989–1014, doi:10.3762/bjnano.8.101

• composition, surface coating, molecular structure, crystal structure, physical, form/shape, particle size, size distribution and surface area, agglomeration state, particle density, ENM bulk density, porosity, dispersibility, solubility in water and biologically relevant fluids, surface charge, and surface

Scaling law to determine peak forces in tapping-mode AFM experiments on finite elastic soft matter systems

• Horacio V. Guzman

Beilstein J. Nanotechnol. 2017, 8, 968–974, doi:10.3762/bjnano.8.98

• has been deduced. Such deduction has been based in the previous works by the author [15]. The fact of reducing the electrostatic interactions of the surface charge depends strongly on the ionic strength and pH values of the liquid [32]. Thus, immersing the surface sample and the probe into a liquid

Near-field surface plasmon field enhancement induced by rippled surfaces

• Mario D’Acunto,
• Francesco Fuso,
• Ruggero Micheletto,
• Makoto Naruse,
• Francesco Tantussi and
• Maria Allegrini

Beilstein J. Nanotechnol. 2017, 8, 956–967, doi:10.3762/bjnano.8.97

• . Our approach follows the so-called surface integral equations (SIEs) [34][35] approach. Initially, we implemented the SIEs based on the boundary element method (BEM), where ad-hoc integral equations for the surface charge and current density must be considered [36]. A second approach was based on a

• represented in Figure 4. Another critical factor that affects the localized hot spots is the polarization [13]. Since the plasmon resonance depends on the restoring force resulting from a noncompensated surface charge, this force depends ultimately on the shape of the topography profile and polarization, i.e

α-((4-Cyanobenzoyl)oxy)-ω-methyl poly(ethylene glycol): a new stabilizer for silver nanoparticles

• Jana Lutze,
• Miguel A. Bañares,
• Marcos Pita,
• Andrea Haase,
• Andreas Luch and
• Andreas Taubert

Beilstein J. Nanotechnol. 2017, 8, 627–635, doi:10.3762/bjnano.8.67

• produces a negatively charged carboxylate (from 4-cyanobenzoic acid attached to the SNP surface) and a neutral alcohol (from the free PEG chains released from the surface). The –OH group does not affect the surface charge at pH 12 but the higher number of negative charges from the cleaved benzoic acid

Gas sensing properties of MWCNT layers electrochemically decorated with Au and Pd nanoparticles

• Elena Dilonardo,
• Michele Penza,
• Marco Alvisi,
• Riccardo Rossi,
• Gennaro Cassano,
• Cinzia Di Franco,
• Francesco Palmisano,
• Luisa Torsi and
• Nicola Cioffi

Beilstein J. Nanotechnol. 2017, 8, 592–603, doi:10.3762/bjnano.8.64

• 12 ± 2 nm and 5.0 ± 0.5 nm, respectively, as reported in the TEM images in Figure 1. The net positive surface charge of colloidal metal NPs, given by the quaternary ammonium surfactant [36][37], was used to functionalize the surface of the MWCNTs by electrophoresis. The lipophilic interactions

Template-controlled piezoactivity of ZnO thin films grown via a bioinspired approach

• Nina J. Blumenstein,
• Fabian Streb,
• Stefan Walheim,
• Thomas Schimmel,
• Zaklina Burghard and
• Joachim Bill

Beilstein J. Nanotechnol. 2017, 8, 296–303, doi:10.3762/bjnano.8.32

• indicates that the sulfonate functionality leads to a highly polar surface of the template, whereas the carboxylate is less negatively charged. However, it has to be taken into account that the deposition experiments take place in methanol. The solvent influences the effective surface charge of the

• ions as can be seen from the pKa values reported by Rived et al. [43]. Therefore, it is probable that the surface charge of the used templates is lower in methanol than it could be expected from zeta potential measurements in water. Nevertheless, the polarity of the two templates is high enough to

• templates. The negative surface charge of the sulfonate-functional groups of the PEL (−115 mV [40]) is high enough to homogeneously attract the dipolar ZnO particles from solution. The result is a closed film even at low numbers of deposition cycles. In contrast, the negative charge density of the

Effect of Anderson localization on light emission from gold nanoparticle aggregates

• Mohamed H. Abdellatif,
• Marco Salerno,
• Gaser N. Abdelrasoul,
• Ioannis Liakos,
• Alice Scarpellini,
• Sergio Marras and
• Alberto Diaspro

Beilstein J. Nanotechnol. 2016, 7, 2013–2022, doi:10.3762/bjnano.7.192

• neutralize the surface charge, having an energy of 7 eV and a filament current of 2.6 A. The C1s was charge corrected to 285.0 eV. XPS spectra for the AuNPs drop-cast on a) quartz and b) glass. SEM images (50,000× magnification) of AuNPs on different substrates of a) glass, b) quartz. PL of AuNPs drop cast

Intercalation and structural aspects of macroRAFT agents into MgAl layered double hydroxides

• Dessislava Kostadinova,
• Ana Cenacchi Pereira,
• Muriel Lansalot,
• Franck D’Agosto,
• Elodie Bourgeat-Lami,
• Fabrice Leroux,
• Christine Taviot-Guého,
• Sylvian Cadars and
• Vanessa Prevot

Beilstein J. Nanotechnol. 2016, 7, 2000–2012, doi:10.3762/bjnano.7.191

• a basal spacing of 0.85 nm, a net shift of the 00l harmonic reflections to lower values of 2θ below 20° was observed for the LDH-macroRAFT compounds, which is consistent with the replacement of nitrate ions by larger anionic species ensuring the layer surface charge neutralization. For PAA49-CTPPA

Functionalized platinum nanoparticles with surface charge trigged by pH: synthesis, characterization and stability studies

• Giovanna Testa,
• Laura Fontana,
• Iole Venditti and
• Ilaria Fratoddi

Beilstein J. Nanotechnol. 2016, 7, 1822–1828, doi:10.3762/bjnano.7.175

• bond on the PtNP surface. The DLS characterization demonstrated the long-term stability of the colloidal system up to three months and the possibility to tune the aggregation phenomenon of the PtNPs by varying the pH due to modulation of the metal surface charge. Experimental Instrumentation UV–vis

Nano- and microstructured materials for in vitro studies of the physiology of vascular cells

• Alexandra M. Greiner,
• Adria Sales,
• Hao Chen,
• Sarah A. Biela,
• Dieter Kaufmann and
• Ralf Kemkemer

Beilstein J. Nanotechnol. 2016, 7, 1620–1641, doi:10.3762/bjnano.7.155

• functionalization. It will be beyond the scope of this review to give a detailed account; only a few examples can be depicted. One simple and often used way to functionalize a surface non-specifically with molecules is by simple physisorption, often after enhancing the surface charge of hardly adhesive surfaces

Viability and proliferation of endothelial cells upon exposure to GaN nanoparticles

• Tudor Braniste,
• Ion Tiginyanu,
• Tibor Horvath,
• Simion Raevschi,
• Serghei Cebotari,
• Marco Lux,
• Axel Haverich and
• Andres Hilfiker

Beilstein J. Nanotechnol. 2016, 7, 1330–1337, doi:10.3762/bjnano.7.124

• living cells and different types of nanoparticles of specific shape, surface charge, and chemical composition [4]. For example, elongated, rod-like gold (Au) nanoparticles affect the viability of endothelial cells more than spherical ones, which have better biocompatibility [5]. However, multiwalled

On the pathway of cellular uptake: new insight into the interaction between the cell membrane and very small nanoparticles

• Claudia Messerschmidt,
• Daniel Hofmann,
• Anja Kroeger,
• Katharina Landfester,
• Volker Mailänder and
• Ingo Lieberwirth

Beilstein J. Nanotechnol. 2016, 7, 1296–1311, doi:10.3762/bjnano.7.121

• specific cellular endocytic mechanisms depending on the material, surface charge or size of the applied nanoparticle [32][33]. So far, less is known about the modes of uptake mediated by physical properties of nanoparticles in the diameter range below 25 nm. With our morphological observations we clearly

Straightforward and robust synthesis of monodisperse surface-functionalized gold nanoclusters

• Silvia Varela-Aramburu,
• Richard Wirth,
• Chian-Hui Lai,
• Guillermo Orts-Gil and
• Peter H. Seeberger

Beilstein J. Nanotechnol. 2016, 7, 1278–1283, doi:10.3762/bjnano.7.118

• polydisperse nanoclusters in terms of both size and shape (data not shown). The absorbance profile of THPC-NCs did not show a plasmon band after the synthesis. However, after three days, a plasmon band appeared, revealing particle aggregation. The surface charge did not change upon dialysis for any sample as

Improved biocompatibility and efficient labeling of neural stem cells with poly(L-lysine)-coated maghemite nanoparticles

• Igor M. Pongrac,
• Marina Dobrivojević,
• Lada Brkić Ahmed,
• Michal Babič,
• Miroslav Šlouf,
• Daniel Horák and
• Srećko Gajović

Beilstein J. Nanotechnol. 2016, 7, 926–936, doi:10.3762/bjnano.7.84

• , Great Britain). The agglomeration properties and the surface charge properties of PLL-γ-Fe2O3 nanoparticles in biological cell culture medium with and without addition of common serum protein were previously described [26]. The crystal structure of both types of nanoparticles was investigated using the

Tight junction between endothelial cells: the interaction between nanoparticles and blood vessels

• Yue Zhang and
• Wan-Xi Yang

Beilstein J. Nanotechnol. 2016, 7, 675–684, doi:10.3762/bjnano.7.60

• exposure to NPs (polystyrene nanoparticles, quantum dots, single-wall carbon nanotubes) results in the disruption of the alveolar epithelial barrier, the extent of which also depends on the composition, shape and surface charge of the NPs [31]. Carbon nanotubes also show their capacity to penetrate the

Antibacterial activity of silver nanoparticles obtained by pulsed laser ablation in pure water and in chloride solution

• Brunella Perito,
• Emilia Giorgetti,
• Paolo Marsili and
• Maurizio Muniz-Miranda

Beilstein J. Nanotechnol. 2016, 7, 465–473, doi:10.3762/bjnano.7.40

• months, we repeated the same tests previously performed with fresh samples. The MIC values were confirmed, indicating good stability of the antimicrobial properties. As previously reported in the literature, AgNPs toxicity depends on various factors, such as size, surface charge, shape, and capping agent

• . In the current study, all our colloids fall in this size range, thus supporting the observed antimicrobial activity. Beyond size effects, surface charge is considered an important parameter for AgNP activity and colloidal stability. The zeta-potential values of our colloids were always very negative

Surface coating affects behavior of metallic nanoparticles in a biological environment

• Darija Domazet Jurašin,
• Marija Ćurlin,
• Ivona Capjak,
• Tea Crnković,
• Marija Lovrić,
• Michal Babič,
• Daniel Horák,
• Ivana Vinković Vrček and
• Srećko Gajović

Beilstein J. Nanotechnol. 2016, 7, 246–262, doi:10.3762/bjnano.7.23

• regardless of their chemical composition, surface structure and surface charge. In addition, an assessment of AgNP and SPION behavior in real biological fluids, rat whole blood (WhBl) and blood plasma (BlPl), revealed that the composition of a biological medium is crucial for the colloidal stability and type

• uptake and toxicity of metallic NPs [41][42], whereas differences in surface coatings influence cytotoxicity and surface charge [43]. However, it is still unclear how different surface coatings affect the interaction of NPs with biological environments and the formation of the protein corona. Because

• with a slightly negative surface charge. Agglomeration behavior of different AgNPs and SPIONs in biological media The DLS and ELS methods were used to quantify the agglomeration of differently coated AgNPs and SPIONs in DMEM, a model biological media (BM), while TEM provided a visual presentation of

Characterisation of thin films of graphene–surfactant composites produced through a novel semi-automated method

• Nik J. Walch,
• Alexei Nabok,
• Frank Davis and
• Séamus P. J. Higson

Beilstein J. Nanotechnol. 2016, 7, 209–219, doi:10.3762/bjnano.7.19

• significant cause of this was poor adhesion of the first graphene layer to hydrophilic substrates. This could be improved in future work through the use of substrates with surface modifications that either enhance the surface charge or make the surface more hydrophobic. Much better results were obtained using

Chemical bath deposition of textured and compact zinc oxide thin films on vinyl-terminated polystyrene brushes

• Nina J. Blumenstein,
• Caroline G. Hofmeister,
• Peter Lindemann,
• Cheng Huang,
• Johannes Baier,
• Andreas Leineweber,
• Stefan Walheim,
• Christof Wöll,
• Thomas Schimmel and
• Joachim Bill

Beilstein J. Nanotechnol. 2016, 7, 102–110, doi:10.3762/bjnano.7.12

• [36] as organic templates are known, which can modify the surface charge on the substrates for ZnO precipitation under moderate conditions. Based on these studies, we investigated the ZnO film formation on silicon wafers modified with vinyl-terminated polystyrene (PS) brushes. Those brushes consist of

• point (IEP), measured in water, of the plasma-cleaned SiOx surface and the PS brushes is 1.5 (extrapolated) and 6.3, respectively (Figure 2). At pH 9 of the reaction solution, the ζ-potential of the Si wafer is much lower (ca. −100 mV) than that of the brushes (ca. −50 mV). This means that the surface

• charge of the SiOx is highly negative whereas under the same conditions, the PS brush is much less negatively charged. It is noteworthy that the reaction takes place in methanol instead of water. For mixtures of water and alcohol it is known, that the ζ-potential is decreasing with higher alcohol content

pH-Triggered release from surface-modified poly(lactic-co-glycolic acid) nanoparticles

• Manuel Häuser,
• Klaus Langer and
• Monika Schönhoff

Beilstein J. Nanotechnol. 2015, 6, 2504–2512, doi:10.3762/bjnano.6.260

• compensation, required to compensate the charge density of the terminating layer, determines the surface charge density of the subsequently adsorbing layer. Thus, an adsorbing charge-diluted chain requires a larger amount of mass, yielding thicker films [21][38]. At pH 3, PAA is weakly charged, and therefore

• directly correlated to the pH of PAA during adsorption. In case of the titration curves obtained for PAA adsorbed at pH 5 and pH 7, respectively, a decrease of surface potential is observed after reaching its maximum value (see Figure 2). This can be attributed to surface charge compensation effects

• . Successive adsorption of PDADMAC as a cationic compound was accomplished, illustrating the importance to choose adsorption conditions allowing an overcompensation of the nanoparticle surface charge. Furthermore, adsorbed PDADMAC was successfully released after application of an appropriate pH-stimulus