Recent progress in actuation technologies of micro/nanorobots

• Ke Xu and
• Bing Liu

Beilstein J. Nanotechnol. 2021, 12, 756–765, doi:10.3762/bjnano.12.59

• bilayers, which also contains an actuator and a clutch inside. When the robot is irradiated by ultraviolet light, the photoresponsive DNA will split into single strands and attach to the microtubules. The slide of microtubules causes the outer cell membrane to change shape, which transforms the robot from

• an inactive sphere to an active moving non-sphere. Conversely, when the robot is illuminated by visible light, the microtubes cannot interact with the membrane, that is to say, the clutch is disengaged, and the robot will also change back to a spherical shape and stop moving. This research

A review of defect engineering, ion implantation, and nanofabrication using the helium ion microscope

• Frances I. Allen

Beilstein J. Nanotechnol. 2021, 12, 633–664, doi:10.3762/bjnano.12.52

• of patches of a silicon nitride membrane that were subsequently perforated by helium ion beam milling to create solid-state nanopores for biomolecule detection. Following this approach, a low fluorescence background was achieved, facilitating the translocation detection of fluorescently labeled

• induced. Future work in this direction using the high-resolution patterning capabilities of the HIM for highly tunable strain engineering on the nanoscale is to be expected. Related to this are the ion implantation-induced membrane folding studies discussed at the end of Section 3. Helium nanobubbles and

• membrane targets by ion implantation. Ion-induced mass transport In one example of a morphological change attributed to ion-induced mass transport, segments of a free-standing GaAs nanowire of 100 nm diameter were irradiated locally with 30 keV helium ions at relatively low dose resulting in local thinning

Stability and activity of platinum nanoparticles in the oxygen electroreduction reaction: is size or uniformity of primary importance?

• Kirill O. Paperzh,
• Anastasia A. Alekseenko,
• Vadim A. Volochaev,
• Ilya V. Pankov,
• Olga A. Safronenko and
• Vladimir E. Guterman

Beilstein J. Nanotechnol. 2021, 12, 593–606, doi:10.3762/bjnano.12.49

• University, "High-Resolution Transmission Electron Microscopy” Shared Use Center, 344090, 194/2 Stachki st., Rostov-on-Don, Russia 10.3762/bjnano.12.49 Abstract Platinum–carbon catalysts are widely used in the manufacturing of proton-exchange membrane fuel cells. Increasing Pt/C activity and stability is an

• . Keywords: durability; electrocatalysts; morphology control; oxygen reduction reaction; platinum nanoparticles; size distribution; spatial distribution; Introduction Nowadays, low-temperature proton-exchange membrane fuel cells (PEMFC) are gaining a wider application. This is due to their environmental

• friendliness, low operating temperature, and high adaptability of specific characteristics [1][2][3]. The key components of PEMFC membrane–electrode assemblies (MEA) are the proton-exchange polymer membrane and porous electrode layers, in which current-forming reactions of oxygen electroreduction (ORR) and

The preparation temperature influences the physicochemical nature and activity of nanoceria

• Robert A. Yokel,
• Wendel Wohlleben,
• Johannes Georg Keller,
• Matthew L. Hancock,
• Jason M. Unrine,
• D. Allan Butterfield and
• Eric A. Grulke

Beilstein J. Nanotechnol. 2021, 12, 525–540, doi:10.3762/bjnano.12.43

• autosampler. In the PSF reservoir, ultrahigh molecular weight polyethylene (UHMWPE) filters prevent clogging of the ultrafiltration membrane in the flow cell. For the standard conditions, 1 mg of ENM was placed on a 5,000 MWCO, 47 mm cellulose triacetate membrane (Stedim Biotech GmbH, Göttingen, Germany

• % sodium dodecyl sulfate for 20 min at room temperature, neutralized, and blotted onto a nitrocellulose membrane for slot-blot analysis with an anti-DNPH rabbit antibody and secondary anti-rabbit IgG alkaline phosphatase antibody, using reagents from the OxyBlot Protein Oxidation Detection Kit (Millipore

A review on nanostructured silver as a basic ingredient in medicine: physicochemical parameters and characterization

• Gabriel M. Misirli,
• Kishore Sridharan and
• Shirley M. P. Abrantes

Beilstein J. Nanotechnol. 2021, 12, 440–461, doi:10.3762/bjnano.12.36

• inhibit virus replication by binding to and regulating cellular and viral proteins and RNAs [114]. Studies indicate that AgNPs did not affect cellular viability, according to mitochondrial cytotoxicity tests, or plasma membrane integrity. Interestingly, they exhibited potent ability to activate

The impact of molecular tumor profiling on the design strategies for targeting myeloid leukemia and EGFR/CD44-positive solid tumors

• Nikola Geskovski,
• Nadica Matevska-Geshkovska,
• Simona Dimchevska Sazdovska,
• Marija Glavas Dodov,
• Kristina Mladenovska and
• Katerina Goracinova

Beilstein J. Nanotechnol. 2021, 12, 375–401, doi:10.3762/bjnano.12.31

• energy and material for membrane biosynthesis, and fat-soluble vitamins [25]. In the past, this pathway was generally ignored as a targeting possibility, mostly because the BM contribution to the RES is quite negligible compared to that of spleen and liver. Also, there was a lack of understanding and

• not internalized after antibody binding, the authors speculate that the NP-enriched cell membrane promotes some kind of “passive” internalization of the functionalized NPs. Protein tyrosine kinase 7 (PTK7) is a highly expressed receptor in AML cells and is mostly assigned to granulocytic lineage

• NALM-6 cell membrane vesicles that were further decorated with aTGFβRII antibodies, attached via hypoxia-sensitive azobenzene linker. The membrane coating plays a dual role in the formulation. It guides the drug to the BM via receptor–ligand interaction between CXCR4 (a chemokine receptor expressed on

Exploring the fabrication and transfer mechanism of metallic nanostructures on carbon nanomembranes via focused electron beam induced processing

• Christian Preischl,
• Linh Hoang Le,
• Elif Bilgilisoy,
• Armin Gölzhäuser and
• Hubertus Marbach

Beilstein J. Nanotechnol. 2021, 12, 319–329, doi:10.3762/bjnano.12.26

• hybrid structure can be lifted off from the substrate and transferred onto bulk substrates, such as SiO2, or onto TEM grids in order to obtain a free-standing CNM with a metallic nanostructure on top. It was shown that the membrane is mechanically stable enough during the whole process and that the

The patterning toolbox FIB-o-mat: Exploiting the full potential of focused helium ions for nanofabrication

• Victor Deinhart,
• Lisa-Marie Kern,
• Jan N. Kirchhof,
• Sabrina Juergensen,
• Joris Sturm,
• Enno Krauss,
• Thorsten Feichtner,
• Sviatoslav Kovalchuk,
• Michael Schneider,
• Dieter Engel,
• Bastian Pfau,
• Bert Hecht,
• Kirill I. Bolotin,
• Stephanie Reich and
• Katja Höflich

Beilstein J. Nanotechnol. 2021, 12, 304–318, doi:10.3762/bjnano.12.25

• sheet was covered by a 500 nm thick PMMA layer. After etching the copper foil, the graphene sheet was transferred onto a SiN membrane with a regular grid of holes. The transfer process is described in detail elsewhere [52]. The SiN membrane was covered with a thin layer of gold, which allowed us to

Doxorubicin-loaded gold nanorods: a multifunctional chemo-photothermal nanoplatform for cancer management

• Uzma Azeem Awan,
• Abida Raza,
• Shaukat Ali,
• Rida Fatima Saeed and
• Nosheen Akhtar

Beilstein J. Nanotechnol. 2021, 12, 295–303, doi:10.3762/bjnano.12.24

• external stimulus [13]. Additionally, the NIR light-induced heat can improve the sensitivity of cancer cells towards chemotherapeutic agents by increasing blood vessel dilation and membrane permeability. These findings provide an incentive to combine photothermal therapy and chemotherapy for cancer

Characterization, bio-uptake and toxicity of polymer-coated silver nanoparticles and their interaction with human peripheral blood mononuclear cells

• Sahar Pourhoseini,
• Reilly T. Enos,
• Angela E. Murphy,
• Bo Cai and
• Jamie R. Lead

Beilstein J. Nanotechnol. 2021, 12, 282–294, doi:10.3762/bjnano.12.23

• . However, for the AgNO3 treatment, this ratio increased in a dose-dependent manner (Table 2). Impact of PVP-AgNPs and Ag ions on viability and metabolic activity of PBMCs Cell membrane integrity as a marker for cell viability was measured by LDH release; a greater LDH release is an indication of more

• ., passivation, or as separate particles) or are bound to proteins. These leads to the formation of secondary NPs, chloro complexes and protein interactions in the RPMI medium yielding a Ag compounds that have a molecular mass above the nominal value of the 3 kDa filter membrane, which affects filter permeation

• synthesis, the NPs were washed by ultrafiltration (3 kDa cellulose membrane EMD Millipore) using a diafiltration technique to avoid drying and NP aggregation as well as to remove any residual reactants. The washing process was repeated at least three times and after each wash the trisodium citrate solution

Differences in surface chemistry of iron oxide nanoparticles result in different routes of internalization

• Barbora Svitkova,
• Vlasta Zavisova,
• Veronika Nemethova,
• Martina Koneracka,
• Miroslava Kretova,
• Filip Razga,
• Monika Ursinyova and
• Alena Gabelova

Beilstein J. Nanotechnol. 2021, 12, 270–281, doi:10.3762/bjnano.12.22

• initiated by the polymerization of clathrin units resulting in the assembly of a basket-like structure (clathrin-coated pit) with a size of 120–150 nm at the inner layer of the plasma membrane [11]. An alternative endocytosis pathway is caveolin-mediated endocytosis (CavME), the second most important route

• of cellular entry. Caveolae are characteristic flask-shaped membrane invaginations with an average size of 50–100 nm [12], lined by caveolin and enriched with cholesterol and sphingolipids. The deeply invaginated clathrin or caveolin pits are then fissured from the membrane by GTPase dynamin

• . Macropinocytosis, a clathrin- and caveolin-independent endocytosis pathway, occurs via actin-driven membrane protrusions. The large endocytic vesicle has a size bigger than 1 µm [13]. Alternative pathways of endocytosis involve other types of cholesterol-rich microdomains called “lipid rafts”, small structures of

The nanomorphology of cell surfaces of adhered osteoblasts

• Christian Voelkner,
• Mirco Wendt,
• Regina Lange,
• Max Ulbrich,
• Martina Gruening,
• Susanne Staehlke,
• Barbara Nebe,
• Ingo Barke and
• Sylvia Speller

Beilstein J. Nanotechnol. 2021, 12, 242–256, doi:10.3762/bjnano.12.20

• micrometers down to the nanometer scale. The cell surface plays a particularly important role. Electric signaling, including information processing, takes place at the membrane, as well as adhesion and contact. For osteoblasts, adhesion and spreading are crucial processes with regard to bone implants. Here we

• characteristic membrane protrusions. They contribute to the overall surface corrugation, which we systematically study by introducing the relative 3D excess area as a function of the projected adhesion area. A clear anticorrelation between the two parameters is found upon analysis of ca. 40 different cells on

• glass and on amine-covered surfaces. At the rim of lamellipodia, characteristic edge heights between 100 and 300 nm are observed. Power spectral densities of membrane fluctuations show frequency-dependent decay exponents with absolute values greater than 2 on living osteoblasts. We discuss the

Scanning transmission helium ion microscopy on carbon nanomembranes

• Daniel Emmrich,
• Annalena Wolff,
• Nikolaus Meyerbröker,
• Jörg K. N. Lindner,
• André Beyer and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2021, 12, 222–231, doi:10.3762/bjnano.12.18

• yield is significantly increased because sputtering occurs not only in backward but also in forward direction [16][17]. To observe and control the milling process, the ion transmission signal is preferred over the SE signal because it is related to the membrane thickness. The detection of the

• [18], Hall measured the thickness of a silicon nitride membrane down to 5 nm using the bright-field signal [19]. A different detection method is the use of a microchannel plate (MCP). Woehl et al. were able to resolve the core–shell structure of silica-coated gold nanoparticles with an annular

• samples. These membranes are made from aromatic molecules, typically from self-assembled monolayers. Upon electron irradiation, cross-linking of the molecules is induced. A mechanically stable membrane is formed, which can be transferred onto any other substrate, such as TEM grids [22][23]. Since CNMs

A review on the biological effects of nanomaterials on silkworm (Bombyx mori)

• Sandra Senyo Fometu,
• Guohua Wu,
• Lin Ma and
• Joan Shine Davids

Beilstein J. Nanotechnol. 2021, 12, 190–202, doi:10.3762/bjnano.12.15

• contact with nanomaterial waste; (D) damage in the membrane and in the lumen of silkworm silk glands; (E) dead zebrafish embryos; (F) NM; (G) contamination of water bodies; (H) silkworm feeding on mulberry leaves containing chemical residues. An illustration of how nanomaterials are directly fed to the

Imaging of SARS-CoV-2 infected Vero E6 cells by helium ion microscopy

• Natalie Frese,
• Patrick Schmerer,
• Martin Wortmann,
• Matthias Schürmann,
• Matthias König,
• Michael Westphal,
• Friedemann Weber,
• Holger Sudhoff and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2021, 12, 172–179, doi:10.3762/bjnano.12.13

• . The HIM pictures show the three-dimensional appearance of SARS-CoV-2 and the surface of Vero E6 cells at a multiplicity of infection of approximately 1 with great morphological detail. The absence of a conductive coating allows for a distinction between virus particles bound to the cell membrane and

• virus particles lying on top of the membrane. After prolonged imaging, it was found that ion-induced deposition of hydrocarbons from the vacuum renders the sample sufficiently conductive to allow for imaging even without charge compensation. The presented images demonstrate the potential of the HIM in

• bioimaging, especially for the imaging of interactions between viruses and their host organisms. Keywords: bioimaging; cell membrane; charge compensation; helium ion microscopy; SARS-CoV-2; Vero E6 cells; Introduction The last decade of helium ion microscopy (HIM) was characterized by a rapid exploration

Paper-based triboelectric nanogenerators and their applications: a review

• Jing Han,
• Nuo Xu,
• Yuchen Liang,
• Mei Ding,
• Junyi Zhai,
• Qijun Sun and
• Zhong Lin Wang

Beilstein J. Nanotechnol. 2021, 12, 151–171, doi:10.3762/bjnano.12.12

• molecules were mostly replaced by nitro groups in order to form a nitrocellulose membrane (NCM), which has a porous structure and a rough surface that improve the triboelectric performance of the constructed TENG. The P-TENGs with a NCM as the negative friction layer have maximum open-circuit voltage (Voc

• paper piano, a printed paper substrate with a back Cu electrode was used as one of the friction layers, while a nitrocellulose membrane was used as the other friction layers in the P-TENG device. The P-TENG-based keyboard paired with bridge rectifiers and capacitors was connected to a laptop through a

A review on the green and sustainable synthesis of silver nanoparticles and one-dimensional silver nanostructures

• Sina Kaabipour and
• Shohreh Hemmati

Beilstein J. Nanotechnol. 2021, 12, 102–136, doi:10.3762/bjnano.12.9

• physicochemical characteristics of AgNPs can be tuned in a way to avoid cellular toxicity [71][74][75], which facilitates their biomedical applications. The small size of AgNPs (<100 nm) allows them to accumulate on the extracellular membrane of the bacteria and penetrate inside, which alters the membrane

Fusion of purple membranes triggered by immobilization on carbon nanomembranes

• René Riedel,
• Natalie Frese,
• Fang Yang,
• Martin Wortmann,
• Raphael Dalpke,
• Daniel Rhinow,
• Norbert Hampp and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2021, 12, 93–101, doi:10.3762/bjnano.12.8

• Max Planck Institute of Biophysics, Department of Structural Biology, Max-von-Laue-Str. 3, D-60438 Frankfurt, Germany 10.3762/bjnano.12.8 Abstract A freestanding ultrathin hybrid membrane was synthesized comprising two functional layers, that is, first, a carbon nanomembrane (CNM) produced by

• electron irradiation-induced cross-linking of a self-assembled monolayer (SAM) of 4′-nitro-1,1′-biphenyl-4-thiol (NBPT) and second, purple membrane (PM) containing genetically modified bacteriorhodopsin (BR) carrying a C-terminal His-tag. The NBPT-CNM was further modified to carry nitrilotriacetic acid

• surface coverage and to close gaps between the PM patches. This procedure for the immobilization of oriented dense PM facilitates the spontaneous fusion of individual PM patches, forming larger membrane areas. This is, to our knowledge, the very first procedure described to induce the oriented fusion of

Effect of different silica coatings on the toxicity of upconversion nanoparticles on RAW 264.7 macrophage cells

• Cynthia Kembuan,
• Helena Oliveira and
• Christina Graf

Beilstein J. Nanotechnol. 2021, 12, 35–48, doi:10.3762/bjnano.12.3

• -aminopropyltrimethoxysilane (AHAPS), which provides the nanoparticle surface with a positive charge, increasing their interaction with the cell membrane. The particles were characterized by scanning transmission electron microscopy (STEM), dynamic light scattering (DLS), electrophoretic light scattering (ELS), and

• surface charge [51]. Positively charged silica particles interact more efficiently with the negatively charged cell membrane than negatively charged particles [45], which can also cause an enhanced uptake [51][52]. This process is supported by the fact that the hydrodynamic diameter of the AHAPS

• cells. In contrast, the amine-functionalized particles were only adsorbed onto the cell membrane. Similar results were also obtained by Kurtz-Chalot et al., in which SiO2 nanoparticles with a high positive charge were more adsorbed than taken up by cells compared to the corresponding non-modified

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

• mitotic HeLa cells that HIM is ready for ultrastructure research in cell biology. Research on the ultrastructure of cells with the HIM was subsequently continued by Schürmann et al., who presented HIM micrographs of cell-membrane nanodomains in mammalian cells [16]. HIM entered the field of virology in

• 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

• published transmission electron micrographs of sections, provided pseudo-3D data. The authors pointed out that using conventional SEM it was not possible to determine whether the glomerular basement membrane defect affects the endothelial structure. However, they stated “HIM allows the endothelial surface

Scanning transmission imaging in the helium ion microscope using a microchannel plate with a delay line detector

• Eduardo Serralta,
• Nico Klingner,
• Olivier De Castro,
• Michael Mousley,
• Santhana Eswara,
• Serge Duarte Pinto,
• Tom Wirtz and
• Gregor Hlawacek

Beilstein J. Nanotechnol. 2020, 11, 1854–1864, doi:10.3762/bjnano.11.167

• based on their gray levels. For this image we used 30 kV acceleration voltage, with a 5 μm aperture, in spot control 5, a gun gas pressure of 1.3 × 10−6 mbar, and 300 μs pixel dwell time. The sample comprises a 20 nm thick silicon nitride membrane used as a support layer. A 20 nm thick layer of silicon

• responsible for the observed mismatch. Beam steering and channeling Polycrystalline silicon A 15 nm thick nanoporous polycrystalline silicon membrane (available from Electron Microscopy Sciences, item number: 76042–79) has been investigated using STIM. In Figure 4b–f we present several STIM images, which were

• , ⟨100⟩-oriented silicon membrane window (available on http://TEMwindows.com, product code: US100-C35Q33). From Figure 6a, one can see that the membrane has wrinkles, which create different angles of incidence between the sample and the incoming beam. The images shown in Figure 6b–e are DF STIM images

Nanocasting synthesis of BiFeO₃ nanoparticles with enhanced visible-light photocatalytic activity

• Thomas Cadenbach,
• Maria J. Benitez,
• A. Lucia Morales,
• Cesar Costa Vera,
• Luis Lascano,
• Francisco Quiroz,
• Alexis Debut and
• Karla Vizuete

Beilstein J. Nanotechnol. 2020, 11, 1822–1833, doi:10.3762/bjnano.11.164

• dyes from wastewater such as precipitation (chemical coagulation, flocculation), membrane and electrochemical processes, as well as biological treatment methods [9]. The main disadvantages of these treatment methods are very often incomplete dye removal, high energy consumption and capital cost, and

• in 30 mL of HNO3-acidified water at pH 3. After stirring the solution for 4 h at room temperature the solvent was removed by evaporation using a membrane pump vacuum on a rotary evaporator at 75 °C. Then, the sample was dried for 16 h in a ventilated oven at 75 °C until a dry powder was obtained

Nanomechanics of few-layer materials: do individual layers slide upon folding?

• Ronaldo J. C. Batista,
• Rafael F. Dias,
• Ana P. M. Barboza,
• Alan B. de Oliveira,
• Taise M. Manhabosco,
• Thiago R. Gomes-Silva,
• Matheus J. S. Matos,
• Andreij C. Gadelha,
• Cassiano Rabelo,
• Luiz G. L. Cançado,
• Ado Jorio,
• Hélio Chacham and
• Bernardo R. A. Neves

Beilstein J. Nanotechnol. 2020, 11, 1801–1808, doi:10.3762/bjnano.11.162

• layered materials as it determines the interlayer slip, which is the dominant mechanism to relieve stress at van der Waals interfaces, leading to phenomena such as the change from plate-like to membrane-like shapes in graphene, hBN, and MoS2 bubbles [12] or the circumferential faceting of multi-walled

• , we mention the recent development of an electromechanical device based on a water-induced electromechanical response in suspended graphene atop a microfluidic channel. The resistivity of the graphene membrane rapidly decreases by approx. 25% upon water injection into the channel due to the reduction

PEG/PEI-functionalized single-walled carbon nanotubes as delivery carriers for doxorubicin: synthesis, characterization, and in vitro evaluation

• Shuoye Yang,
• Zhenwei Wang,
• Yahong Ping,
• Yuying Miao,
• Yongmei Xiao,
• Lingbo Qu,
• Lu Zhang,
• Yuansen Hu and
• Jinshui Wang

Beilstein J. Nanotechnol. 2020, 11, 1728–1741, doi:10.3762/bjnano.11.155

• enhance the dispersion of particles by electrostatic repulsion [25][30]. Cellular entry and uptake of these carriers can be considerably enhanced by cationic modification and passive drug delivery to a tumor site due to high membrane binding avidity can be achieved. In this study, SWCNTs conjugated with

• to shorten SWCNTs, that is, H2SO4/H2O2 (1:1, v/v), HNO3, and H2SO4/HNO3 (1:3, v/v). Subsequently, the suspension was intensively stirred at 80 °C for 8 h. After that, the mixture was refluxed and diluted with distilled water, and then filtrated through a 0.22 µm PTFE microporous membrane. The product

Cardiomyocyte uptake mechanism of a hydroxyapatite nanoparticle mediated gene delivery system

• Hiroaki Komuro,
• Masahiro Yamazoe,
• Kosuke Nozaki,
• Akiko Nagai and
• Tetsuo Sasano

Beilstein J. Nanotechnol. 2020, 11, 1685–1692, doi:10.3762/bjnano.11.150

• can be taken up by cells via passive transport or active transport. Most nanoparticles are taken up by endocytosis (i.e., active transport) and rarely by direct penetration through the plasma membrane (i.e., passive transport). The endocytic pathway is an energy-dependent process; therefore, it can be

• incubated with 25 µg/mL of TMR–dextran (Mw: 70,000) (Invitrogen) at 37 °C for 30 min. The cells were washed three times with PBS, to remove free TMR–dextran or membrane-bound dextran, fixed with 4% paraformaldehyde for 10 min, and stained with the nuclear dye Hoechst 33343. To quantify macropinocytosis