Long-term stability and scale-up of noncovalently bound gold nanoparticle-siRNA suspensions

• Anna V. Epanchintseva,
• Julia E. Poletaeva,
• Dmitrii V. Pyshnyi,
• Elena I. Ryabchikova and
• Inna A. Pyshnaya

Beilstein J. Nanotechnol. 2019, 10, 2568–2578, doi:10.3762/bjnano.10.248

• degradation of molecules, attachment of extra molecules from the incubation medium, and irreversible aggregation of the particles. Previous studies concerning vehicles for TNAs describe their therapeutic effect but not their stability and storage conditions [12][13][14][20][21]. The storage problem of the

• buffers with different pH values by analyzing the optical absorption spectra in the range of 400–800 nm (Figure 2). We did not observe a wide peak in the range of 650–700 nm, which would indicate nanoparticle aggregation. This peak appeared only in the case of mixing of the AuNP-siRNA suspension with the

• nanoconstructions of TNA and metal nanoparticles is not covered in the literature, and began the study of this issue starting with a short period of 24 h. We focused on studying the main signs of preparation spoiling, aggregation of AuNP-siRNA and disruption of siRNA molecules (loss of duplex integrity). The

Advanced hybrid nanomaterials

• Andreas Taubert,
• Fabrice Leroux,
• Pierre Rabu and
• Verónica de Zea Bermudez

Beilstein J. Nanotechnol. 2019, 10, 2563–2567, doi:10.3762/bjnano.10.247

• yield diverse materials, which were found to depend on the P/Ti atom ratio [20]. The ratio was found to determine the particle size and the aggregation state and thereby could strongly tune the porosity of the resulting materials. Colloidal chemistry with patchy silica nanoparticles was employed to

• SAXS” to identify and characterize subtle interparticle interactions [24]. This study shows that fast in situ synchrotron SAXS provides an understanding of lysozyme deformation molecules during aggregation. All these contributions indicate a marked interest of current research in hybrid materials for

Bombesin receptor-targeted liposomes for enhanced delivery to lung cancer cells

• Mohammad J. Akbar,
• Pâmela C. Lukasewicz Ferreira,
• Melania Giorgetti,
• Leanne Stokes and
• Christopher J. Morris

Beilstein J. Nanotechnol. 2019, 10, 2553–2562, doi:10.3762/bjnano.10.246

• that are sufficiently resistant to aggregation in body fluids such as blood. The stability of control and targeted liposomes was examined after exposure to 10% heat-inactivated FBS for 24 or 72 h at different temperatures (Figure 3c,d). There were noticeable increased in liposome size and PDI as a

Small protein sequences can induce cellular uptake of complex nanohybrids

• Jan-Philip Merkl,
• Malak Safi,
• Christian Schmidtke,
• Fadi Aldeek,
• Johannes Ostermann,
• Tatiana Domitrovic,
• Sebastian Gärtner,
• John E. Johnson,
• Horst Weller and
• Hedi Mattoussi

Beilstein J. Nanotechnol. 2019, 10, 2477–2482, doi:10.3762/bjnano.10.238

• stability and tumour accumulation of curcumin [17]. Overall, there is a consensus that using colloidally stable nanoparticles is crucial for understanding and controlling cellular uptake, because materials that are prone to aggregation show higher non-specific interactions with biological fluids and cell

• stability studies in culture media were first carried out. We found no sign of aggregation build up for at least 5 hours, as verified using dynamic light scattering measurements, where mono-modal autocorrelation function along with a single intensity vs hydrodynamic size peak (i.e., Laplace transform

pH-Controlled fluorescence switching in water-dispersed polymer brushes grafted to modified boron nitride nanotubes for cellular imaging

• Saban Kalay,
• Yurij Stetsyshyn,
• Volodymyr Donchak,
• Khrystyna Harhay,
• Ostap Lishchynskyi,
• Halyna Ohar,
• Yuriy Panchenko,
• Stanislav Voronov and
• Mustafa Çulha

Beilstein J. Nanotechnol. 2019, 10, 2428–2439, doi:10.3762/bjnano.10.233

• aggregation of poly(acrylic acid) due to hydrophobic interactions was shown [54]. At neutral or basic pH, the hydrodynamic diameter of the poly(acrylic acid) macromolecules was significantly decreased, indicating the disruption of intermolecular aggregates [54]. Cellular imaging using P(AA-co-FA

Air oxidation of sulfur mustard gas simulants using a pyrene-based metal–organic framework photocatalyst

• Ghada Ayoub,
• Mihails Arhangelskis,
• Xuan Zhang,
• Florencia Son,
• Timur Islamoglu,
• Tomislav Friščić and
• Omar K. Farha

Beilstein J. Nanotechnol. 2019, 10, 2422–2427, doi:10.3762/bjnano.10.232

• the catalytic activity of Py-DCA, most likely due to the heterogeneous nature of the MOF, which assembles the pyrene linkers periodically within a robust three-dimensional framework, preventing their deactivation through aggregation. In all cases the 1O2 acted as a highly selective oxidant for the

Coating of upconversion nanoparticles with silica nanoshells of 5–250 nm thickness

• Cynthia Kembuan,
• Maysoon Saleh,
• Bastian Rühle,
• Ute Resch-Genger and
• Christina Graf

Beilstein J. Nanotechnol. 2019, 10, 2410–2421, doi:10.3762/bjnano.10.231

• thicknesses of about 40–50 nm, followed by the growth of a thick silica layer by continuously adding TEOS in a Stöber-like growth step. Thereby, particle aggregation, which can occur during a Stöber-like growth process, and the formation of NPs from the shell material can be elegantly prevented, and

• indicate low colloidal stability of the particles, which is also supported by the high PDI values suggesting partial aggregation (Table 1). Repeated centrifugation and redispersion in ethanol were carried out in an attempt to improve the colloidal stability by removing the remaining surfactant from the

The role of Ag⁺, Ca²⁺, Pb²⁺ and Al³⁺ adions in the SERS turn-on effect of anionic analytes

• Stefania D. Iancu,
• Andrei Stefancu,
• Vlad Moisoiu,
• Loredana F. Leopold and
• Nicolae Leopold

Beilstein J. Nanotechnol. 2019, 10, 2338–2345, doi:10.3762/bjnano.10.224

• aggregation agent [1][2]. Consequently, many studies explain the SERS effect by the formation of electromagnetic hot-spots, i.e., sites with highly increased field strengths generated by the aggregated nanoparticles. Early SERS studies highlighted the importance of a strong electronic coupling between the

• in the SERS effect was evidenced experimentally also by Watanabe et al. and Doering et al., who showed that thiosulfate, a photographic fixing agent that dissolves Ag+ ions, completely quenches the SERS signal [8][12]. Furthermore, the aggregation of nanoparticles was completely excluded since the

• − showing a high affinity for the silver surface. The colloidal nanoparticles used here are surrounded by citrate anions in an electrostatic interaction with the silver surface, which confer the nanoparticles a negative zeta potential and thus electrostatically stabilize the AgNPs and prevent aggregation

Microfluidics as tool to prepare size-tunable PLGA nanoparticles with high curcumin encapsulation for efficient mucus penetration

• Nashrawan Lababidi,
• Valentin Sigal,
• Aljoscha Koenneke,
• Konrad Schwarzkopf,
• Andreas Manz and
• Marc Schneider

Beilstein J. Nanotechnol. 2019, 10, 2280–2293, doi:10.3762/bjnano.10.220

• small NPs were obtained. Another reason could be that the rate of the NP growth decreased as well [43][44]. Markedly, the tendency of NP aggregation decreased at a higher flow of the aqueous phase due to the large volume of the aqueous phase, which prevents particle interaction (this was indicated by

• different channel lengths could be observed. According to literature, nanoprecipitation is more linked to nucleation and growth, which consists of three stages: nucleation, growth, and aggregation, as illustrated in Figure 8 [52]. Based on the theoretical description of the mechanism, the particle formation

• is dependent on the time available for growth and agglomeration. Aggregation is assumed to happen after the initial formation and it is assumed to depend on the length of the mixing channel [36]. Therefore, adjusting the length of the mixing channel to only allow for nuclei formation should hinder NP

Targeted therapeutic effect against the breast cancer cell line MCF-7 with a CuFe₂O₄/silica/cisplatin nanocomposite formulation

• B. Rabindran Jermy,
• Vijaya Ravinayagam,
• Widyan A. Alamoudi,
• Dana Almohazey,
• Hatim Dafalla,
• Lina Hussain Allehaibi,
• Abdulhadi Baykal,
• Muhammet S. Toprak and
• Thirunavukkarasu Somanathan

Beilstein J. Nanotechnol. 2019, 10, 2217–2228, doi:10.3762/bjnano.10.214

• form aggregates, exert variable oxidation states and result in dose-dependent toxicity. Several supports, including silica and carbon, were used to reduce such aggregation. Notably, different types of nanocomposites were reported based on Co, Ni, Mn and Fe over mesoporous carbon capsules [8]. A carbon

Mannosylated brush copolymers based on poly(ethylene glycol) and poly(ε-caprolactone) as multivalent lectin-binding nanomaterials

• Stefania Ordanini,
• Wanda Celentano,
• Anna Bernardi and
• Francesco Cellesi

Beilstein J. Nanotechnol. 2019, 10, 2192–2206, doi:10.3762/bjnano.10.212

• aggregates (e.g., micelles and vesicles) above their critical aggregation concentration (CAC). The resulting self-assembled nanoparticles can act as drug carriers and delivery systems, being able to accommodate a hydrophobic drug within their hydrophobic core [22], or chemically bind bioactive agents [23][24

• , Table 3). This result may be ascribed to an effect of the different polymer composition on the aggregation kinetics. As general trend, the rate constant k of Con A clustering decreased as the valency increased, and consequently the time to reach half of the maximum turbidity t1/2 increased as the

• /2 was calculated as the time to reach half of the maximum optical density in the OD curve. The first three points of the curve was fit with a straight line and its slope was used to determine the initial rate of Con A aggregation k. Synthetic approach (upper panel), final structure and nomenclature

Nonlinear absorption and scattering of a single plasmonic nanostructure characterized by x-scan technique

• Tushar C. Jagadale,
• Dhanya S. Murali and
• Shi-Wei Chu

Beilstein J. Nanotechnol. 2019, 10, 2182–2191, doi:10.3762/bjnano.10.211

• reasonable. Sample preparation As samples, we used 80 nm diameter gold nanospheres commercially available from BBI Solutions, UK. Before use, the nanostructure solution was sonicated for 2 min to avoid particle aggregation. Then, one drop of the solution was placed on polysine slides (Thermo Fisher

Improved adsorption and degradation performance by S-doping of (001)-TiO₂

• Xiao-Yu Sun,
• Xian Zhang,
• Xiao Sun,
• Ni-Xian Qian,
• Min Wang and
• Yong-Qing Ma

Beilstein J. Nanotechnol. 2019, 10, 2116–2127, doi:10.3762/bjnano.10.206

• solid-state calcination results in the aggregation of particles. For S-doping via hydrothermal methods, the precursors were placed in an oven or a muffle furnace and heated to induce the reaction. Although some progress has already been made concerning S-doped TiO2, there are many issues that require

• ratios, reaching a maximum at RS/Ti = 3. This is a result of the different ionic radius of S compared to O and Ti, which are replaced. (2) S-doping changes the morphology of the particles and results in the aggregation of particles; consequently, the specific surface area decreases. (3) S-doping

Microbubbles decorated with dendronized magnetic nanoparticles for biomedical imaging: effective stabilization via fluorous interactions

• Da Shi,
• Justine Wallyn,
• Dinh-Vu Nguyen,
• Francis Perton,
• Delphine Felder-Flesch,
• Sylvie Bégin-Colin,
• Mounir Maaloum and
• Marie Pierre Krafft

Beilstein J. Nanotechnol. 2019, 10, 2103–2115, doi:10.3762/bjnano.10.205

• , which contributes to a further increase of the hydrodynamic radius. The mean diameter of the IONP@C4X9OEG8Den materials was larger, namely ≈95 nm and ≈200 nm for X = H and F, respectively, revealing that aggregation occurs in aqueous media due to the hydrophobicity of the end group. Fortunately, this

• IONP samples are well-dispersed with no indication of aggregation. The films of spin-coated DPPC form large monolayer and small bilayer domains (Figure 10a). The profile measured on the magnified image (Figure 10b and Figure 10c) shows that the heights of the monolayer and bilayer are 1.5 ± 0.3 nm and

The importance of design in nanoarchitectonics: multifractality in MACE silicon nanowires

• Stefania Carapezzi and
• Anna Cavallini

Beilstein J. Nanotechnol. 2019, 10, 2094–2102, doi:10.3762/bjnano.10.204

• nanosized dimensions of the basic units. Because the spatial layout is self-driven in contrast to a hetero-directed placement, asymmetric interaction potentials and entropic forces can lead to different aggregation schemes from place to place and across the scales of the generated structures. The control

Ion mobility and material transport on KBr in air as a function of the relative humidity

• Dominik J. Kirpal,
• Korbinian Pürckhauer,
• Alfred J. Weymouth and
• Franz J. Giessibl

Beilstein J. Nanotechnol. 2019, 10, 2084–2093, doi:10.3762/bjnano.10.203

• and recorded the evolution of these defects as a function of the time. We observed an exponential decay of the size of the defects and material accumulations, and from this data we determined energy barriers to dissolution and aggregation of approximately 0.9 eV. Keywords: ambient conditions; atomic

Incorporation of doxorubicin in different polymer nanoparticles and their anticancer activity

• Sebastian Pieper,
• Hannah Onafuye,
• Dennis Mulac,
• Jindrich Cinatl Jr.,
• Mark N. Wass,
• Martin Michaelis and
• Klaus Langer

Beilstein J. Nanotechnol. 2019, 10, 2062–2072, doi:10.3762/bjnano.10.201

• PVA at concentrations between 2% and 4% (w/v) and controlled injection at mild stirring had previously been shown to produce PLGA-PEG nanoparticles with a diameter below 100 nm [35][36][37]. The hydrophilic PEG chains may sterically stabilise the nanoparticles by reducing PLGA aggregation during

Optimization and performance of nitrogen-doped carbon dots as a color conversion layer for white-LED applications

• Tugrul Guner,
• Hurriyet Yuce,
• Didem Tascioglu,
• Eren Simsek,
• Umut Savaci,
• Aziz Genc,
• Servet Turan and
• Mustafa M. Demir

Beilstein J. Nanotechnol. 2019, 10, 2004–2013, doi:10.3762/bjnano.10.197

• becomes almost one at the highest amount of N-CDots (50 µL, blue line). Meanwhile, the PL intensity of the resulting PVP/N-CDot composites drops dramatically as the amount of the N-CDots increases. Such a reduction is expected due to aggregation-induced luminescence quenching (AILQ) [57][58][59], enhanced

• decreases as the N-CDot amount is increased (at fixed amount of red phosphor). This behavior possibly results from aggregation-induced luminescence quenching and enhanced scattering of the light within the composites. In the case of the sample CDR 3, adding more red phosphor at the fixed N-CDots amount

Gold-coated plant virus as computed tomography imaging contrast agent

• Alaa A. A. Aljabali,
• Mazhar S. Al Zoubi,
• Khalid M. Al-Batanyeh,
• Ali Al-Radaideh,
• Mohammad A. Obeid,
• Abeer Al Sharabi,
• Walhan Alshaer,
• Bayan AbuFares,
• Tasnim Al-Zanati,
• Murtaza M. Tambuwala,
• Naveed Akbar and
• David J. Evans

Beilstein J. Nanotechnol. 2019, 10, 1983–1993, doi:10.3762/bjnano.10.195

• limited coalescence. Au-CPMV assemblies were freely suspended; no aggregation was observed by nanoparticle tracking analysis (NTA) or dynamic light scattering (DLS). The successful coating of CPMV particles with gold was confirmed by TEM (Figure 1). Nearly spherical NPs were observed the average diameters

• the surface functionalities allows for the use of such particles in biomedical applications. The Au-CPMV particles reported here exhibit excellent stability over at least almost a year. No visible aggregation nor changes in particles size was observed in samples stored at 4 °C. Their surface can be

• clustering and indicating highly monodisperse particles with no aggregation, each dot represents a single particle; (C) representative NTA video frame. Data was recorded from six independent experiments. (A) UV–vis spectrum of 50 nm unconjugated Au-CPMV (green) and antibody-labeled Au-CPMV particles (blue

Porous silver-coated pNIPAM-co-AAc hydrogel nanocapsules

• William W. Bryan,
• Riddhiman Medhi,
• Maria D. Marquez,
• Supparesk Rittikulsittichai,
• Michael Tran and
• T. Randall Lee

Beilstein J. Nanotechnol. 2019, 10, 1973–1982, doi:10.3762/bjnano.10.194

• degradation, as indicated by visible aggregation and loss of the extinction peak intensity. At elevated temperatures, the hydrogel cores are in a desolvated state as indicated by the swollen and collapsed architectures shown in Figure 3. Furthermore, a reduction in the overall surface charge distribution is

• , such as formaldehyde, following a seeded-growth method [77]. Figure 4a and Figure 4c confirm that the particles are well-dispersed after nanocapsule growth with no aggregation, and the diameters of 929 ± 42 nm and 920 ± 58 nm were determined for the porous and smooth Ag nanocapsules, respectively

• suspended in 40 mL of water and kept at room temperature. The hydrogel particles showed no signs of visible aggregation, and their size (≈800 nm in diameter) was controlled by adjusting the amount of initiator and the reaction time. Attachment of THPC gold seeds to pNIPAM-co-AAc hydrogel particles. For the

The influence of porosity on nanoparticle formation in hierarchical aluminophosphates

• Matthew E. Potter,
• Lauren N. Riley,
• Alice E. Oakley,
• Panashe M. Mhembere,
• June Callison and
• Robert Raja

Beilstein J. Nanotechnol. 2019, 10, 1952–1957, doi:10.3762/bjnano.10.191

• aggregation, leading to increased catalyst lifetime and performance [5]. Yet, immobilisation further complicates nanoparticle design by introducing surface–nanoparticle interactions, which have been shown to have a significant influence on the catalytic efficacy [6]. Commonly, the supports used are porous

• , which allows the nanoparticle to be deposited, and yet sufficiently isolated from other particles, to hinder aggregation. Of the wide range of supports utilised in the literature, micro- and meso-porous species are the most common [7][8][9][10]. Microporous materials can achieve high levels of control

High-tolerance crystalline hydrogels formed from self-assembling cyclic dipeptide

• Yongcai You,
• Ruirui Xing,
• Qianli Zou,
• Feng Shi and
• Xuehai Yan

Beilstein J. Nanotechnol. 2019, 10, 1894–1901, doi:10.3762/bjnano.10.184

• rheological properties. The crystal structure remained unchanged (Figure 3E) and no obvious aggregation or precipitation was observed. Also, the microtopography of the hydrogel exhibited no obvious changes (Supporting Information File 1, Figure S1). The environmental conditions, such as pH and temperature

Biocatalytic oligomerization-induced self-assembly of crystalline cellulose oligomers into nanoribbon networks assisted by organic solvents

• Yuuki Hata,
• Yuka Fukaya,
• Toshiki Sawada,
• Masahito Nishiura and
• Takeshi Serizawa

Beilstein J. Nanotechnol. 2019, 10, 1778–1788, doi:10.3762/bjnano.10.173

• solution. The addition of appropriate organic solvents to the oligomerization system was found to result in well-grown nanoribbon networks. The organic solvents appeared to prevent irregular aggregation and subsequent precipitation of the nanosheets via solvation for further growth into the well-grown

• viscosity and depletion repulsion, which prevented the nanosheet-shaped lamellar crystals from aggregation and subsequent precipitation, enabling the formation of well-grown nanoribbon networks. On the other hand, the organic solvents used in this study were small molecules, indicating a different mechanism

• showed that organic solvents provided control over the oligomerization-induced self-assembly of cellulose oligomers. The organic solvents with relatively high β-values prevented the irregular aggregation of the particulate nanostructures for the formation of well-organized higher-order structures. The

Layered double hydroxide/sepiolite hybrid nanoarchitectures for the controlled release of herbicides

• Ediana Paula Rebitski,
• Margarita Darder and
• Pilar Aranda

Beilstein J. Nanotechnol. 2019, 10, 1679–1690, doi:10.3762/bjnano.10.163

• Figure S4, Supporting Information File 1). This behavior is probably related to the fact that size and aggregation state of the LDH nanoparticles increase with the LDH content in the nanoarchitecture, slowing down the kinetics of the process. The measured release after 8 h of contact with water varies

Chiral nanostructures self-assembled from nitrocinnamic amide amphiphiles: substituent and solvent effects

• Hejin Jiang,
• Huahua Fan,
• Yuqian Jiang,
• Li Zhang and
• Minghua Liu

Beilstein J. Nanotechnol. 2019, 10, 1608–1617, doi:10.3762/bjnano.10.156

• nm and 293 nm, respectively. This result suggests a H-like aggregation of NCLG molecules through π–π stacking. CD spectroscopy is considered to be a useful technique to monitor the supramolecular assembly. Consequently, distinct CD signals were obtained for the assemblies of the three NCLG molecules