AgCl-doped CdSe quantum dots with near-IR photoluminescence

• Pavel A. Kotin,
• Sergey S. Bubenov,
• Natalia E. Mordvinova and
• Sergey G. Dorofeev

Beilstein J. Nanotechnol. 2017, 8, 1156–1166, doi:10.3762/bjnano.8.117

• unequivocally to the absence of a significant contribution of Ag2Se to the PL spectra. Also, we assume that Ag2Se NPs could be formed in our case, but they were separated from our samples in the post-synthetic stage due to their low colloidal stability [31]. Conclusion In our work we investigated CdSe–AgCl

Dispersion of single-wall carbon nanotubes with supramolecular Congo red – properties of the complexes and mechanism of the interaction

• Anna Jagusiak,
• Barbara Piekarska,
• Tomasz Pańczyk,
• Małgorzata Jemioła-Rzemińska,
• Elżbieta Bielańska,
• Barbara Stopa,
• Grzegorz Zemanek,
• Janina Rybarska,
• Irena Roterman and
• Leszek Konieczny

Beilstein J. Nanotechnol. 2017, 8, 636–648, doi:10.3762/bjnano.8.68

• further experiments. SWNT–CR complexes obtained in the method described above retained their colloidal stability for at least 3 months (stored at 4 °C or at room temperature). The amount of CR bound by SWNTs was determined spectrophotometrically based on the amount of CR in the eluate as compared to the

• /SWNT ratios. Macroscopic images of complexes filtered on PTFE membrane and suspended in pH 7.4 0.05 M Tris/HCl buffer. (A) 1 mL of 2 mg/mL CR added to 1 mg of SWNTs – the complex retained its colloidal stability for up to 3 months; (B) 1 mL of 5 mg/mL CR added to 1 mg of SWNTs – the gel-like, time

Uptake of the proteins HTRA1 and HTRA2 by cells mediated by calcium phosphate nanoparticles

• Olga Rotan,
• Katharina N. Severin,
• Simon Pöpsel,
• Alexander Peetsch,
• Melisa Merdanovic,
• Michael Ehrmann and
• Matthias Epple

Beilstein J. Nanotechnol. 2017, 8, 381–393, doi:10.3762/bjnano.8.40

• substitution 0.7; 2 mg mL−1) or aqueous polyethyleneimine solution (PEI; Sigma-Aldrich, Mw = 25 kDa; 2 mg mL−1), respectively, to achieve the colloidal stability of the nanoparticle dispersion. These particles were used either as-prepared (denoted as CaP/CMC and CaP/PEI) or further loaded with proteins. For

• (Table 2). All nanoparticles had a hydrodynamic diameter between 250 and 350 nm. The zeta potential reflects the corresponding charge of the polyelectrolyte polymer used for the stabilization (CMC: negative charge, PEI: positive charge) that indicates the colloidal stability of the nanoparticles in

Nanoscale isoindigo-carriers: self-assembly and tunable properties

• Tatiana N. Pashirova,
• Andrei V. Bogdanov,
• Lenar I. Musin,
• Julia K. Voronina,
• Irek R. Nizameev,
• Marsil K. Kadirov,
• Vladimir F. Mironov,
• Lucia Ya. Zakharova,
• Shamil K. Latypov and
• Oleg G. Sinyashin

Beilstein J. Nanotechnol. 2017, 8, 313–324, doi:10.3762/bjnano.8.34

• room temperature (for more than 80 days). The zeta potentials of SIPs from 2d, 2e, 2f, 2h are about −34, −28, −30, −39 mV, respectively (Table S1, Figure S1, Supporting Information File 1). To characterize the colloidal stability of the compounds under study in the presence of electrolytes, the

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

• colloidal stability; hydrophobic or hydrophilic thiol-based ligands have been deeply exploited [14][15]. Among others, 2-diethylaminoethanethiol hydrochloride (DEA) has been used as a stabilizing thiol for gold nanoparticles used for the immobilization of lipase [16]. Among others, hydrothermal and

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

• -potential values were very negative, indicating excellent long-term colloidal stability. Antibacterial activity was observed against both microorganisms for the four AgNP formulations, but the ps-ablated nanoparticles were shown to more effectively inhibit the growth of both microorganisms. Moreover, LiCl

• obtained by laser ablation [32]. In order to study the long-term colloidal stability and the electrical characteristics of the NP surface, the zeta potential was measured. The obtained values are reported in Table 1. Apart from the AgNPsLiClps sample, all samples exhibited a bimodal distribution of the

• . 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

• biocompatibility. This study is aimed to evaluate the effects of surface coating on colloidal stability and behavior of AgNPs and SPIONs in modelled biological environments using dynamic and electrophoretic light scattering techniques, as well as transmission electron microscopy to visualize the behavior of the NP

• 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

• of metallic NP transformation. Our results highlight the importance of physicochemical characterization and stability evaluation of metallic NPs in a variety of biological systems including as many NP properties as possible. Keywords: biological fluids; colloidal stability; maghemite; nanoparticles

Silica-coated upconversion lanthanide nanoparticles: The effect of crystal design on morphology, structure and optical properties

• Uliana Kostiv,
• Miroslav Šlouf,
• Hana Macková,
• Alexander Zhigunov,
• Hana Engstová,
• Katarína Smolková,
• Petr Ježek and
• Daniel Horák

Beilstein J. Nanotechnol. 2015, 6, 2290–2299, doi:10.3762/bjnano.6.235

• . Surface modification of the particles using silica precursors enhanced colloidal stability and facilitated the transfer of the crystals in aqueous media. Experimental Materials Sodium and yttrium(III) trifluoroacetate, ytterbium(III) chloride hexahydrate, erbium(III) chloride hexahydrate, oleylamine (OM

Synthesis, characterization and in vitro effects of 7 nm alloyed silver–gold nanoparticles

• Simon Ristig,
• Svitlana Chernousova,
• Wolfgang Meyer-Zaika and
• Matthias Epple

Beilstein J. Nanotechnol. 2015, 6, 1212–1220, doi:10.3762/bjnano.6.124

• nanoparticles [31], leads to a considerably faster reduction rate than citrate alone and also increases the colloidal stability of the resulting nanoparticles. We demonstrate the versatility of this synthetic route for the generation of alloyed nanoparticles using the silver/gold ratio as a size control over

• presented herein is well suited for the generation of monodisperse, bimetallic, Ag/Au nanoparticles of different molar compositions. The particles can be coated with a polymer shell (e.g., PVP) for enhanced colloidal stability in aqueous medium. The characterization of the nanoparticles using complementary

Protein corona – from molecular adsorption to physiological complexity

• Lennart Treuel,
• Dominic Docter,
• Michael Maskos and
• Roland H. Stauber

Beilstein J. Nanotechnol. 2015, 6, 857–873, doi:10.3762/bjnano.6.88

• corona formation for both, the particle, and the protein. We review consequences of corona formation for colloidal stability and discuss the role of functional groups and NP surface functionalities in shaping NP–protein interactions. We also elaborate the recent advances demonstrating the strong

• predict. More detailed investigations under specific conditions of biological systems are needed to allow for a more educated assessment. A further very important aspect of corona formation is its impact on colloidal stability: Under physiological conditions, many NPs lose their original stabilization due

• current achievements and remaining gaps. Review Colloidal stability and the corona Many NPs are found to aggregate in media that contain electrolytes in high concentrations [74][100][101][102][103]. To prevent NPs from agglomeration upon collision with one another, they are usually stabilized in solution

Influence of gold, silver and gold–silver alloy nanoparticles on germ cell function and embryo development

• Ulrike Taylor,
• Daniela Tiedemann,
• Christoph Rehbock,
• Wilfried A. Kues,
• Stephan Barcikowski and
• Detlef Rath

Beilstein J. Nanotechnol. 2015, 6, 651–664, doi:10.3762/bjnano.6.66

• (<3 nm) [91][92][93][94]. In case of the latter it was shown that surface functionalisation had an additional influence on the severity and the characteristica of the observed toxicity [93][94]. Another interesting point raised was the impact of colloidal stability in the final exposure medium on the

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

• to guarantee optimum colloidal stability). Two time points were chosen: 0 (at 25 °C) and after 4 h incubation at 37 °C, representing the starting and end point of particle incubation. DLS analyses were performed using a Microtrac NANO-flex (with a 180° backscattering setup). As it involves the least

• (containing 2 mmol/L sodium bromide to guarantee optimum colloidal stability). Two time points were chosen: 0 and 4 h, representing the starting and end point of particle incubation. Acknowledgements The experimental work described herein was carried out by Lisa Feiden under supervision of Dr. Jennifer Y

Biological responses to nanoscale particles

• Reinhard Zellner

Beilstein J. Nanotechnol. 2015, 6, 380–382, doi:10.3762/bjnano.6.37

• studies of nanoparticles) that the surface area seems to be one of the properties that causes a severe biological response, other properties such as solubility, hydrophobicity, surface functionalization, surface charge, colloidal stability and nanoparticle morphology have been suggested to be of equal

The effect of surface charge on nonspecific uptake and cytotoxicity of CdSe/ZnS core/shell quantum dots

• Vladimir V. Breus,
• Anna Pietuch,
• Marco Tarantola,
• Thomas Basché and
• Andreas Janshoff

Beilstein J. Nanotechnol. 2015, 6, 281–292, doi:10.3762/bjnano.6.26

• DPA–QDs show minimal aggregation due to the low pKa value (4.73) of the DHLA carboxylic group [32] and the colloidal stability over a wide pH range of the zwitterionic coating, respectively [33]. In order to clarify whether the CA–QDs and DHLA–QDs affect the cells differently due to their surface

• immediate toxicity caused by QDs. For negatively charged DHLA–QDs and zwitterionic DPA–QDs, the decrease in the cellular impedance was the most pronounced, reduced to 50% of the initial value. 50 nM solutions of CA–QDs and MPA–QDs (for which limited colloidal stability was expected) both had the smallest

Mammalian cell growth on gold nanoparticle-decorated substrates is influenced by the nanoparticle coating

• Christina Rosman,
• Sebastien Pierrat,
• Marco Tarantola,
• David Schneider,
• Eva Sunnick,
• Andreas Janshoff and
• Carsten Sönnichsen

Beilstein J. Nanotechnol. 2014, 5, 2479–2488, doi:10.3762/bjnano.5.257

• with the negatively charged membrane [21][22], and to the sedimentation behavior of the particles which is related to their colloidal stability under physiological conditions [33]. The uptake was likely caused by non-specific endocytosis or macropinocytosis. Therefore, we expected an even stronger

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

• . This is to prevent osmotic tension of the vesicle membrane at the beginning of an experiment. The colloidal stability of the particles under these conditions was confirmed by dynamic light scattering (DLS). Figure 9 describes the easy experimental procedure. Due to the slight density difference between

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

• synthesis of monodisperse, well-defined hetero-nanostructures requires non-hydrolytic reaction conditions, as established for the isotropic analogues. Therefore, it is necessary to exchange the hydrophobic surface functionalization of the nanoparticles by hydrophilic ligands to secure colloidal stability in

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

• potential and the excellent colloidal stability of the DHLA-coated NPs. Zwitterionic surfaces, however, are famous for their hydrophobicity, protein adsorption resistance and anti-fouling properties, which strongly argues against a destabilizing effect of DPA-QDs [51]. Of note is that our measured ΔRH value

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

• responsible for the colloidal stability of the dispersion. Generally, the absolute value of the zeta potential decreases under conditions of high salinity, which are predominant in cell culture medium. For example, for NexSil20, a zeta potential value of −20 mV is found. However, under conditions of

• reveal a decrease in colloidal stability of the samples after quaternization. Zeta potential measurements show a rather constant value of approximately +30 mV in 5 mM NaBr for all three samples indicating that, at least under low salt conditions, the degree of quaternization does not influence the charge

• of the particles. PEG@POS-NH2: With the introduction of PEG, the mechanism of colloidal stabilization is changed towards steric stabilization and colloidal stability is expected to increase. However, the DLS measurement of the resulting sample PEG@POS-NH2 revealed a hydrodynamic radius of 41.5 nm and

Influence of surface-modified maghemite nanoparticles on in vitro survival of human stem cells

• Michal Babič,
• Daniel Horák,
• Lyubov L. Lukash,
• Tetiana A. Ruban,
• Yurii N. Kolomiets,
• Svitlana P. Shpylova and
• Oksana A. Grypych

Beilstein J. Nanotechnol. 2014, 5, 1732–1737, doi:10.3762/bjnano.5.183

• ][25]. In particular, PDMAAm-coated γ-Fe2O3 nanoparticles exhibited a long-term colloidal stability even after more than six months of storage. All types of γ-Fe2O3 nanoparticles displayed superparamagnetic behavior [29], which is characterized by a strong response to a magnetic field and zero remanent

• magnetization. This is proven by the quick separation of such particles in a magnetic field and the easy redispersion by Brownian motion into a liquid medium after removing the magnet. It is obvious that the colloidal stability of the particles is a prerequisite to their biomedical applications. Thanks to the

Current state of laser synthesis of metal and alloy nanoparticles as ligand-free reference materials for nano-toxicological assays

• Christoph Rehbock,
• Jurij Jakobi,
• Lisa Gamrad,
• Selina van der Meer,
• Daniela Tiedemann,
• Ulrike Taylor,
• Wilfried Kues,
• Detlef Rath and
• Stephan Barcikowski

Beilstein J. Nanotechnol. 2014, 5, 1523–1541, doi:10.3762/bjnano.5.165

• anionic surface moieties [42]. The most probable explanation is that positively charged gold surfaces attract water molecules, oxygen and carbon dioxide, forming a pH-dependent equilibrium of Au–OH/Au–O− and Au–CO3− groups [44][45]. Generally, these surface charges lead to a good colloidal stability due

• interfere with toxicity assays. Even though the addition of ions is generally believed to compromise colloidal stability due to a reduction of the Debye length, previous studies reported an anion specific stabilization and destabilization of laser generated gold nanoparticles [44]. Furthermore, size control

• , reference nanoparticles may be considered ideal hard spheres whose colloidal stability is entirely driven by electrostatic effects, which may be well characterized by their electrophoretic mobility (zeta-potential) [103]. Under these conditions, colloidal stability is basically influenced by three

In vitro interaction of colloidal nanoparticles with mammalian cells: What have we learned thus far?

• Moritz Nazarenus,
• Qian Zhang,
• Mahmoud G. Soliman,
• Pablo del Pino,
• Beatriz Pelaz,
• Susana Carregal-Romero,
• Joanna Rejman,
• Barbara Rothen-Rutishauser,
• Martin J. D. Clift,
• Reinhard Zellner,
• G. Ulrich Nienhaus,
• James B. Delehanty,
• Igor L. Medintz and
• Wolfgang J. Parak

Beilstein J. Nanotechnol. 2014, 5, 1477–1490, doi:10.3762/bjnano.5.161

• number of fundamental principles exist, which are outlined in this review. Keywords: colloidal stability; intracellular particle distribution; nanoparticles; protein corona; toxicity of nanoparticles; Introduction There is a multitude of reports about the interaction of colloidal nanoparticles (NPs

• physicochemical properties of the NPs can be found. One, however, has to be aware that many physicochemical properties of NPs, such as size, shape, charge, and colloidal stability are highly entangled [14]. The physicochemical properties are not intrinsically associated with the NPs, but result from the

• interaction of the NPs with the surrounding particular medium [87]. The colloidal stability is presumably the most influential parameter. NPs with low colloidal stability will agglomerate and thus, originally "small" NPs will transform into agglomerates, resulting in large particles presented to the cells (cf

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

• were measured in water, the colloidal stability is expected to be best when the surface-charge-stabilized silica particles are dispersed in water containing low concentrations of salt. Nevertheless, all presented particles show hydrodynamic diameters in the range of the primary particle size also in

• to link individual or multiple particle parameters, such as geometry, pore size or surface functionalization to the observed nanobiological effects. The negative zeta potential, hydrodynamic diameter and colloidal stability of the ASP dispersions were obtained in water, salt-containing buffer, and

Characterization and photocatalytic study of tantalum oxide nanoparticles prepared by the hydrolysis of tantalum oxo-ethoxide Ta₈(μ₃-O)₂(μ-O)₈(μ-OEt)₆(OEt)₁₄

• Subia Ambreen,
• N D Pandey,
• Peter Mayer and
• Ashutosh Pandey

Beilstein J. Nanotechnol. 2014, 5, 1082–1090, doi:10.3762/bjnano.5.121

• manner that their hydrophobic surfaces point toward the solvent and render colloidal stability and uniformity of the particles in organic solvents [23]. The TOPO coated particles suspended in chloroform were precipitated by adding excess methanol followed by centrifuging at 2000 rpm and re-dispersed in

Nanodiamond-DGEA peptide conjugates for enhanced delivery of doxorubicin to prostate cancer

• Amanee D Salaam,
• Patrick Hwang,
• Roberus McIntosh,
• Hadiyah N Green,
• Ho-Wook Jun and
• Derrick Dean

Beilstein J. Nanotechnol. 2014, 5, 937–945, doi:10.3762/bjnano.5.107

• size and zeta potential are particularly important for drug delivery applications as they give representations of size limitations and potential colloidal stability issues of a system. NDs permeate the cell membrane by endocytosis [20][36][37]. Through this pathway, NDs can effectively deliver drugs

• measurements, but the size of the ND-DGEA+DOX system was within the optimal range for drug delivery (<100 nm). The zeta potential indicated that the colloidal stability decreased with each modification of the NDs. At a prepared concentration of 200 µg/mL, the zeta potentials for pure NDs, ND-DGEA, and ND-DGEA