Graphene oxide–chloroquine conjugate induces DNA damage in A549 lung cancer cells through autophagy modulation

• Braham Dutt Arya,
• Sandeep Mittal,
• Prachi Joshi,
• Alok Kumar Pandey,
• Jaime E. Ramirez-Vick,
• Govind Gupta and
• Surinder P. Singh

Beilstein J. Nanotechnol. 2025, 16, 316–332, doi:10.3762/bjnano.16.24

• buffer, post-fixed in 1% osmium tetraoxide for 4 h at 4 °C, and again washed with 0.1 M sodium cacodylate buffer. After that, cells were dehydrated using different percentages of acetone series (15–100%) and incubated with an AralditeR–DDSA mixture overnight at room temperature. The cell blocks were made

Ultrablack color in velvet ant cuticle

• Vinicius Marques Lopez,
• Wencke Krings,
• Juliana Reis Machado,
• Stanislav Gorb and
• Rhainer Guillermo-Ferreira

Beilstein J. Nanotechnol. 2024, 15, 1554–1565, doi:10.3762/bjnano.15.122

• –2.00 hPa. For sample preparation, transversely sectioned T. bifurca specimens were fixed in Karnovsky fixative solution + 0.1% ruthenium red for 12 h. Following buffer washing, a post-fixative solution (osmium tetroxide + 0.1% ruthenium red) was applied at room temperature. After rinsing with alcohol

• , Leica Biosystems, Solms, Germany) and contrasted with osmium tetroxide. Confocal laser scanning microscopy (CLSM) The capacity of insect cuticle to emit autofluorescence at various wavelengths is extensively documented, influenced by material composition, degree of sclerotization, and the presence of

Effect of radiation-induced vacancy saturation on the first-order phase transformation in nanoparticles: insights from a model

• Aram Shirinyan and
• Yuriy Bilogorodskyy

Beilstein J. Nanotechnol. 2024, 15, 1453–1472, doi:10.3762/bjnano.15.117

• , typical values for the migration energy of ceramics (Emα and Emβ) range from approximately 2.0 to 4.0 eV, while for metals, typical values (Emα and Emβ) range from 0.1 to 2.5 eV (osmium has Em = 3 eV) [25][26][27][28]. As a result, ceramics should be better suited for describing radiation-induced phase

Functional morphology of cleaning devices in the damselfly Ischnura elegans (Odonata, Coenagrionidae)

• Silvana Piersanti,
• Gianandrea Salerno,
• Wencke Krings,
• Stanislav Gorb and
• Manuela Rebora

Beilstein J. Nanotechnol. 2024, 15, 1260–1272, doi:10.3762/bjnano.15.102

• % glutaraldehyde in sodium cacodylate buffer (Electron Microscopy Sciences, Hatfield, PA, USA) with a pH of 7.2, repeatedly rinsed in sodium cacodylate buffer and post-fixed for 1 h at 4 °C in 1% osmium tetroxide in sodium cacodylate buffer (Electron Microscopy Sciences). Fixed samples were repeatedly rinsed in

The origin of black and white coloration of the Asian tiger mosquito Aedes albopictus (Diptera: Culicidae)

• Manuela Rebora,
• Gianandrea Salerno,
• Silvana Piersanti,
• Alexander Kovalev and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2023, 14, 496–508, doi:10.3762/bjnano.14.41

• cacodylate buffer (Electron Microscopy Sciences, Hatfield, England), pH 7.2. The fixed legs were repeatedly rinsed in sodium cacodylate buffer and post-fixed for 1 h at 4 °C in 1% osmium tetroxide in sodium cacodylate buffer (Electron Microscopy Sciences). The samples were then repeatedly washed in the same

Surfactant-free syntheses and pair distribution function analysis of osmium nanoparticles

• Mikkel Juelsholt,
• Jonathan Quinson,
• Emil T. S. Kjær,
• Baiyu Wang,
• Rebecca Pittkowski,
• Susan R. Cooper,
• Tiffany L. Kinnibrugh,
• Søren B. Simonsen,
• Luise Theil Kuhn,
• María Escudero-Escribano and
• Kirsten M. Ø. Jensen

Beilstein J. Nanotechnol. 2022, 13, 230–235, doi:10.3762/bjnano.13.17

• ] complexes. Keywords: metal nanoparticles; osmium; pair distribution function; surfactant-free synthesis; Findings Precious metals are limited resources, yet fundamental for a range of applications, such as in medicine or catalysis [1][2][3]. There are relatively few reports on osmium (Os) compared to

Fate and transformation of silver nanoparticles in different biological conditions

• Barbara Pem,
• Marija Ćurlin,
• Darija Domazet Jurašin,
• Valerije Vrček,
• Rinea Barbir,
• Vedran Micek,
• Raluca M. Fratila,
• Jesus M. de la Fuente and
• Ivana Vinković Vrček

Beilstein J. Nanotechnol. 2021, 12, 665–679, doi:10.3762/bjnano.12.53

• were post-fixed in 2% osmium tetroxide in the same buffer for 30 min. All the specimens were then dehydrated in a series of graded alcohols, and embedded in TAAB embedding resin (TAAB, Aldermaston, UK). After sectioning on a Leica UC6 ultramicrotome (Leica Microsystems, Vienna, Austria) using a Diatome

Bio-imaging with the helium-ion microscope: A review

• Matthias Schmidt,
• James M. Byrne and
• Ilari J. Maasilta

Beilstein J. Nanotechnol. 2021, 12, 1–23, doi:10.3762/bjnano.12.1

• sometimes treated with additional chemicals, such as 1% tannic acid (TA), and/or osmium-fixed to promote membrane integrity [61]. After fixation, water is removed from samples via dehydration in ethanol or methanol with increasing concentrations, for example, 30%, 75%, 95%, and 100% for 10 min each [60][62

• to be directly and clearly visualised.” Using HIM, Schürmann et al. impressively showed how closely ultrastructural details of cell membranes visualised by HIM are linked to sample preparation [16]. In the study, lipid nanodomains in mammalian cells were investigated. HIM was used to image osmium

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

• with osmium. The fracture surface was observed by a field-emission scanning electron microscope (JSM-7500F, JEOL) at an accelerating voltage of 5 kV. Analysis of the secondary structure of CDP The secondary structure of CDP was analyzed by CD spectroscopy. CDP was dissolved in a 8 mM phosphate buffer

Mo-doped boron nitride monolayer as a promising single-atom electrocatalyst for CO₂ conversion

• Qianyi Cui,
• Gangqiang Qin,
• Weihua Wang,
• Lixiang Sun,
• Aijun Du and
• Qiao Sun

Beilstein J. Nanotechnol. 2019, 10, 540–548, doi:10.3762/bjnano.10.55

• of CO2 to CH4 is 0.64 and 0.77 eV [9]. In addition, the performance of Mo-doped BN is comparable to or even better than some catalysts composed of noble metals, such as titania-modified silver (0.47 eV) [48], and osmium and ruthenium atom doped graphene (0.52 eV) [26]. The Mo-doped BN monolayer

A new bioinspired method for pressure and flow sensing based on the underwater air-retaining surface of the backswimmer Notonecta

• Matthias Mail,
• Adrian Klein,
• Horst Bleckmann,
• Anke Schmitz,
• Torsten Scherer,
• Peter T. Rühr,
• Goran Lovric,
• Robin Fröhlingsdorf,
• Stanislav N. Gorb and
• Wilhelm Barthlott

Beilstein J. Nanotechnol. 2018, 9, 3039–3047, doi:10.3762/bjnano.9.282

• microstructure of the setal bases. The hemelytra were cut into several pieces. The pieces were fixed in 2.5% glutaraldehyde and 1.5% osmium tetroxide in cacodylate buffer (380 mOsmol, pH 7.1). After dehydrating in ethanol, the pieces were embedded in Epon 812 via epoxy propane as an intermedium. The clavus and

The structural and chemical basis of temporary adhesion in the sea star Asterina gibbosa

• Birgit Lengerer,
• Marie Bonneel,
• Mathilde Lefevre,
• Elise Hennebert,
• Philippe Leclère,
• Emmanuel Gosselin,
• Peter Ladurner and
• Patrick Flammang

Beilstein J. Nanotechnol. 2018, 9, 2071–2086, doi:10.3762/bjnano.9.196

• in cacodylate buffer (0.1 M. pH 7.8, with 1.55% NaCl) for 3 h at 4 °C. The tube feet were rinsed in cacodylate buffer (0.2 M. pH 7.8, with 1.84% NaCl) and then post-fixed in 1% osmium tetroxide in cacodylate buffer (0.1 M. pH 7.8, with 2.3% NaCl). After rinsing in cacodylate buffer, the tube feet

Involvement of two uptake mechanisms of gold and iron oxide nanoparticles in a co-exposure scenario using mouse macrophages

• Dimitri Vanhecke,
• Dagmar A. Kuhn,
• Dorleta Jimenez de Aberasturi,
• Sandor Balog,
• Ana Milosevic,
• Dominic Urban,
• Diana Peckys,
• Niels de Jonge,
• Wolfgang J. Parak,
• Alke Petri-Fink and
• Barbara Rothen-Rutishauser

Beilstein J. Nanotechnol. 2017, 8, 2396–2409, doi:10.3762/bjnano.8.239

• in 0.15 M cacodylate buffer. Staining occurred with osmium tetraoxide in ddH2O. After the staining, membranes were transferred to 0.05 M maleate buffer and dehydrated with an increased ethanol series (30% and 70%). The membranes were embedded in epon and polymerized at 60 °C. The samples were

Low uptake of silica nanoparticles in Caco-2 intestinal epithelial barriers

• Dong Ye,
• Mattia Bramini,
• Delyan R. Hristov,
• Sha Wan,
• Anna Salvati,
• Christoffer Åberg and
• Kenneth A. Dawson

Beilstein J. Nanotechnol. 2017, 8, 1396–1406, doi:10.3762/bjnano.8.141

• in Sorensen’s phosphate buffer, and post fixed in osmium tetroxide (1%, w/v) in de-ionised water for 1 h. The samples were rinsed in Sorensen’s phosphate buffer and dehydrated by incubation in 30%, 50%, 70%, 90% and 100% ethanol solutions. The cells were immersed in ethanol/Epon (1:1, v/v) mixture

False positives and false negatives measure less than 0.001% in labeling ssDNA with osmium tetroxide 2,2’-bipyridine

• Anastassia Kanavarioti

Beilstein J. Nanotechnol. 2016, 7, 1434–1446, doi:10.3762/bjnano.7.135

• Anastassia Kanavarioti Yenos Analytical LLC, El Dorado Hills, CA, USA 10.3762/bjnano.7.135 Abstract Osmium tetroxide 2,2’-bipyridine (OsBp) is known to react with pyrimidines in ssDNA and preferentially label deoxythymine (T) over deoxycytosine (C). The product, osmylated DNA, was proposed as a

• properties of the degradation products via nanopore translocation can be evaluated to assure base calling quality in a DNA sequencing effort. Keywords: α-hemolysin; capillary electrophoresis; DNA sequencing; high-performance liquid chromatography; nanopores; osmium tetroxide bipyridine; osmylated oligos

• it was found that one of the contrast agents, a 1:1 mixture of osmium tetroxide and 2,2’-bipyridine, exhibited extraordinary properties, and was considered to be the “perfect” label (Scheme 1). These attributes are (i) room temperature reactivity at mM concentration, (ii) no loss of label upon

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

• % osmium tetroxide, 0.1% uranylacetate and 5% water) was pre-cooled to −90 °C before samples were added. Finally, the samples were embedded in EPON 812 and sectioned at room temperature using a diamond knife. For elemental analysis, some of these specimens were additionally coated with a thin carbon layer

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

• reagent, washed once with DMEM/F-12 medium, separated by centrifugation and fixed overnight with 2% glutaraldehyde in 0.1 M phosphate buffer, post-fixed in 1% osmium tetroxide, and contrasted in 2% uranyl acetate in water. The samples were dehydrated in acetone and embedded in resin Durcupan (Sigma

Time-dependent growth of crystalline Au⁰-nanoparticles in cyanobacteria as self-reproducing bioreactors: 2. Anabaena cylindrica

• Liz M. Rösken,
• Felix Cappel,
• Susanne Körsten,
• Christian B. Fischer,
• Andreas Schönleber,
• Sander van Smaalen,
• Stefan Geimer,
• Christian Beresko,
• Georg Ankerhold and
• Stefan Wehner

Beilstein J. Nanotechnol. 2016, 7, 312–327, doi:10.3762/bjnano.7.30

• samples were chemically fixed using glutaraldehyde and osmium tetroxide, dehydrated and embedded in epoxy resin according to standard procedures, see Supporting Information File 1 for a detailed description of the method. Ultrathin sections (about 60 nm thick) were analyzed in a Zeiss EM 902A transmission

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

• Sarstedt (Belgium). Osmium tetroxide was purchased from Agar Scientific (Stansted, UK) and TAAB epoxy resin (medium hard) from Aldermaston (Berkshire, UK). All dilutions were made with ultrapure water (18.2 MΩ·cm), obtained from a GenPureUltraPure water system (TKA Wasseraufbereitungssysteme GmbH

Single pyrimidine discrimination during voltage-driven translocation of osmylated oligodeoxynucleotides via the α-hemolysin nanopore

• Yun Ding and
• Anastassia Kanavarioti

Beilstein J. Nanotechnol. 2016, 7, 91–101, doi:10.3762/bjnano.7.11

• surrogate for nanopore-based sequencing. Osmylation is the addition of osmium tetroxide 2,2’-bipyridine (OsBp) to the C5–C6 pyrimidine double bond. The process is simple, selective for deoxythymidine (dT) over deoxycytidine (dC), unreactive towards the purines, practically 100% effective, and strikingly

• above detection limits, may be further optimized, and clear the way for nanopore-based sequencing using osmylated DNA. Keywords: DNA sequencing; α-hemolysin; ion-channel measurements; nanopore; osmium tetroxide bipyridine; osmylated oligos; osmylation; single-stranded DNA (ssDNA); Introduction

• molecules to label ssDNA, we evaluated OsBp [42]. OsBp is known to add to the C5–C6 double bond of the pyrimidine ring (Scheme 1). Because osmium is a good contrast agent for imaging by electron microscopy (EM), osmylated DNA was proposed 60 years ago and exploited in attempts to obtain DNA sequence

Ultrastructural changes in methicillin-resistant Staphylococcus aureus induced by positively charged silver nanoparticles

• Dulce G. Romero-Urbina,
• Humberto H. Lara,
• J. Jesús Velázquez-Salazar,
• M. Josefina Arellano-Jiménez,
• Eduardo Larios,
• Anand Srinivasan,
• Jose L. Lopez-Ribot and
• Miguel José Yacamán

Beilstein J. Nanotechnol. 2015, 6, 2396–2405, doi:10.3762/bjnano.6.246

• areas where osmium did not penetrate, as seen in Figure 3. The bacterial cells are generally intact. Furthermore, the cell walls of the untreated MRSA and MSSA cells seem rigid, and their PG layers are thick, measuring approximately 40 nm compared to approximately 32 nm in the case of the treated

• bacterial cells (see below in Figure 7b). Electron microscopy of treated MSSA and MRSA HAADF-STEM images of treated MRSA and MSSA cells demonstrate the affinity between silver and osmium that can generate electron-dense particles around the bacterial cell wall, as seen in Figure 4a; specific cases of AgNPs

• % osmium tetroxide (OsO4) at room temperature. After washing the bacterial cells with PBS to eliminate excess OsO4, a dehydration series was performed with 25, 50, 75, 95 and 100% ethanol. The samples were further dehydrated with propylene oxide, embedded in a resin (LX112) and left to harden for 48 h at

Coating with luminal gut-constituents alters adherence of nanoparticles to intestinal epithelial cells

• Heike Sinnecker,
• Katrin Ramaker and
• Andreas Frey

Beilstein J. Nanotechnol. 2014, 5, 2308–2315, doi:10.3762/bjnano.5.239

• cells were treated according to the protocol of Bye et al. [32]. They were washed once with 0.1 M sodium cacodylate (pH 7.4) and fixed with a solution containing osmium tetroxide and glutaraldehyde as fixatives (0.5% osmium tetroxide (Polysciences Europe GmbH, Eppelheim, Germany), 2.5% glutaraldehyde

Imaging the intracellular degradation of biodegradable polymer nanoparticles

• Anne-Kathrin Barthel,
• Martin Dass,
• Melanie Dröge,
• Jens-Michael Cramer,
• Daniela Baumann,
• Markus Urban,
• Katharina Landfester,
• Volker Mailänder and
• Ingo Lieberwirth

Beilstein J. Nanotechnol. 2014, 5, 1905–1917, doi:10.3762/bjnano.5.201

• injected into a high pressure freezing device (Wohlwend, Switzerland). The frozen sandwich was stored in liquid N2. The aluminum cover was removed in a liquid N2 environment and the sapphire disk was transferred into anhydrous acetone at −90 °C, (Merck, Germany) containing 4% aqueous osmium tetroxide (Roth

Mimicking exposures to acute and lifetime concentrations of inhaled silver nanoparticles by two different in vitro approaches

• Fabian Herzog,
• Kateryna Loza,
• Sandor Balog,
• Martin J. D. Clift,
• Matthias Epple,
• Peter Gehr,
• Alke Petri-Fink and
• Barbara Rothen-Rutishauser

Beilstein J. Nanotechnol. 2014, 5, 1357–1370, doi:10.3762/bjnano.5.149

• least 24 h, subsequently washed with potassium phosphate buffer and post-fixed with 1% osmium tetroxide in sodium cacodylate buffer, washed with maleate buffer, and stained en bloc with 0.5% uranyl acetate in maleate buffer. Afterwards, the cells were dehydrated in ascending ethanol series, and embedded