Antimicrobial metal-based nanoparticles: a review on their synthesis, types and antimicrobial action

• Matías Guerrero Correa,
• Fernanda B. Martínez,
• Cristian Patiño Vidal,
• Camilo Streitt,
• Juan Escrig and
• Carol Lopez de Dicastillo

Beilstein J. Nanotechnol. 2020, 11, 1450–1469, doi:10.3762/bjnano.11.129

• agents. Although the most studied nanoparticles with antimicrobial properties are metallic or metal-oxide nanoparticles, other types of nanoparticles, such as superparamagnetic iron-oxide nanoparticles and silica-releasing systems also exhibit antimicrobial properties. Finally, since the quantification

• field [19]. An interesting strategy to increase the antimicrobial efficiency of metal-based nanoparticles is the use of silica and carbon compounds as delivery systems [20]. The broad range of metal-based nanoparticles, the types of NP synthesis, and their antimicrobial activity were further explored in

• by using a 60 mg mL−1 SPION solution and applying an alternating current for 8 min. Silica- and carbon-derived nanoparticles Over the last years, several studies have revealed that silica nanoparticles are excellent antimicrobial metal-releasing systems due to their high chemical and thermal

One-step synthesis of carbon-supported electrocatalysts

• Sebastian Tigges,
• Nicolas Wöhrl,
• Ivan Radev,
• Ulrich Hagemann,
• Markus Heidelmann,
• Thai Binh Nguyen,
• Stanislav Gorelkov,
• Stephan Schulz and
• Axel Lorke

Beilstein J. Nanotechnol. 2020, 11, 1419–1431, doi:10.3762/bjnano.11.126

• deposited in the silica glass tube leading from the oven to the deposition chamber. In contrast, low carrier gas flow rates and moderate to high pressures (small absolute gas velocities) resulted in substantial oxidation of the Pt-NPs in the layer, as can be seen when comparing sample P6 to P2. Remarkably

• geometry (see Supporting Information File 1, Figure S1). Platinum acetylacetonate (98%, abcr GmbH) was placed inside an evaporator at the backside of the chamber, a silica glass tube was fitted to the exhaust of the evaporator that pointed towards the substrate holder, and the reactor chamber was evacuated

Role of redox-active axial ligands of metal porphyrins adsorbed at solid–liquid interfaces in a liquid-STM setup

• Thomas Habets,
• Sylvia Speller and
• Johannes A. A. W. Elemans

Beilstein J. Nanotechnol. 2020, 11, 1264–1271, doi:10.3762/bjnano.11.110

• suppliers (ACROS Organics or Sigma-Aldrich), independent whether it was vacuum-distilled prior to use or used as received. For TLC analysis, TLC silicagel 60 F254 (Merck, Burlington, MA, USA) and for column chromatography silica gel 0.035–0.070 mm, (Acros, Branchburg, N.J., USA) was used. MALDI-TOF mass

• subsequently purified by column chromatography (silica 60H, eluent CH2Cl2/MeOH 9:1, v/v) to yield MnTUPOAc (48 mg, 86%) as a dark green solid. MALDI-TOFMS m/z 979 [M‒OAc]+; UV–vis (CH2Cl2) λ/nm (log(ε/M−1cm−1)): 397 (4.52), 375 (4.60), 481 (4.95), 548 (3.35), 604 (3.56), 640 (4.01). Experiments in the liquid

Influence of the magnetic nanoparticle coating on the magnetic relaxation time

• Mihaela Osaci and
• Matteo Cacciola

Beilstein J. Nanotechnol. 2020, 11, 1207–1216, doi:10.3762/bjnano.11.105

• applicability of the magnetic nanoparticles. In this regard, the optimized microemulsion method can be used to obtain a homogenous silica coating on Fe3−xO4 nanoparticles [14]. This method controls the thickness of the coating layer, enabling a higher average separation among particles when compared to the

Straightforward synthesis of gold nanoparticles by adding water to an engineered small dendrimer

• Sébastien Gottis,
• Régis Laurent,
• Vincent Collière and
• Anne-Marie Caminade

Beilstein J. Nanotechnol. 2020, 11, 1110–1118, doi:10.3762/bjnano.11.95

• fibers stabilized by amines (AuI, ca. 3.25 Å) [10], but slightly longer than in the case of gold particles in silica glass and gold foil (2.84 Å) [61] or in bulk gold (2.88427 Å) [10]. The dependence between the gold nanoparticle shape and the conditions in which they were generated is the subject of a

Applications of superparamagnetic iron oxide nanoparticles in drug and therapeutic delivery, and biotechnological advancements

• Maria Suciu,
• Corina M. Ionescu,
• Alexandra Ciorita,
• Septimiu C. Tripon,
• Dragos Nica,
• Hani Al-Salami and
• Lucian Barbu-Tudoran

Beilstein J. Nanotechnol. 2020, 11, 1092–1109, doi:10.3762/bjnano.11.94

• of iron oxides in the form of magnetite (Fe3O4) or maghemite (Fe2O3) and are easy to produce through a few well-documented synthesis methods yielding different forms and structures (e.g., round, cubic, hexagonal, clusters, core–shell with gold, silica, polymers, or surfactants). A lot of research is

• vessels [36]. This problem limits the usefulness of SPIONs as targeting agents [124]. Macrophage recognition of nanoparticles can be used for the desired treatment as well. Ullah et al. used the rapid macrophage endocytosis of silica-coated SPIONs loaded with maytansin, an antiproliferative toxin. They

Plant growth regulation by seed coating with films of alginate and auxin-intercalated layered double hydroxides

• Vander A. de Castro,
• Valber G. O. Duarte,
• Danúbia A. C. Nobre,
• Geraldo H. Silva,
• Vera R. L. Constantino,
• Frederico G. Pinto,
• Willian R. Macedo and
• Jairo Tronto

Beilstein J. Nanotechnol. 2020, 11, 1082–1091, doi:10.3762/bjnano.11.93

• suspension was maintained at pH 9.5 ± 0.5 by the slow addition of a 1.0 mol·L−1 solution of NaOH and the system was kept under constant agitation in a N2 atmosphere. The solid resulting from the synthesis was washed with H2O and dried under reduced pressure in a desiccator containing silica gel. The amount

• . After completion of the synthesis, the whole reaction medium was kept at rest for 12 h. The solid resulting from the synthesis was centrifuged and dried under reduced pressure in a desiccator containing silica gel. Coating of bean seeds with a polymeric film Polymeric gels were prepared by dissolving

Hexagonal boron nitride: a review of the emerging material platform for single-photon sources and the spin–photon interface

• Stefania Castelletto,
• Faraz A. Inam,
• Shin-ichiro Sato and
• Alberto Boretti

Beilstein J. Nanotechnol. 2020, 11, 740–769, doi:10.3762/bjnano.11.61

A novel dry-blending method to reduce the coefficient of thermal expansion of polymer templates for OTFT electrodes

• Xiangdong Ye,
• Bo Tian,
• Yuxuan Guo,
• Fan Fan and
• Anjiang Cai

Beilstein J. Nanotechnol. 2020, 11, 671–677, doi:10.3762/bjnano.11.53

• a sol–gel precursor by adding tetraethyl orthosilicate (TEOS) to polyvinyl pyrrolidone (PVP), and then synthesized a silica/PVP nanofiber composite by electrospinning. The content of silica nanofibers in the composite is 9.1 wt %, and the CTE was decreased by ca. 40%. Jeyranpour et al. [13] studied

• the influence of fullerene (C60) on the CTE of Araldite LY 5052/Aradur HY 5052 cross-linked epoxy resin by molecular dynamics simulations. The CTE was minimized by adding a maximum of 15.9 wt % fullerene to the LY/HY/C60 epoxy system. Liu et al. [14] selected MCM-41 mesoporous silica nanoparticles

• with a size of 300 nm to be doped into polydimethylsiloxane (PDMS) to prepare a PDMS/MCM-41 nanocomposite. The CTE of the nanocomposite decreased from the initial 301 ppm/°C of PDMS to 241 ppm/°C, when the content of silica in PDMS was increased to 20 wt %. To further reduce the CTE of the polymer

Identification of physicochemical properties that modulate nanoparticle aggregation in blood

• Ludovica Soddu,
• Duong N. Trinh,
• Eimear Dunne,
• Dermot Kenny,
• Giorgia Bernardini,
• Ida Kokalari,
• Arianna Marucco,
• Marco P. Monopoli and
• Ivana Fenoglio

Beilstein J. Nanotechnol. 2020, 11, 550–567, doi:10.3762/bjnano.11.44

• causing both pro- and anti-coagulant properties. There is contrasting evidence on how the physicochemical properties of the material modulate these effects. In this work, we developed two sets of tailored carbon and silica nanoparticles with three different diameters in the 100–500 nm range with the

• role. On the other hand, large carbon nanoparticles (but not small carbon nanoparticles or silica nanoparticles) have a clear tendency to form aggregates both in plasma and blood. This effect was observed both in the presence or absence of platelets and was independent of platelet activation. Overall

• currently not clear which properties lead to the activation of the coagulation. For example, positive charged dendritic NPs were found to be more thrombogenic than negatively charged ones while positive and negative charged polystyrene NPs both induce platelet activation [7][8]. Carbon and silica

Multilayer capsules made of weak polyelectrolytes: a review on the preparation, functionalization and applications in drug delivery

• Varsha Sharma and
• Anandhakumar Sundaramurthy

Beilstein J. Nanotechnol. 2020, 11, 508–532, doi:10.3762/bjnano.11.41

• ]. It was reported that when an 8- or 16-layer capsule core was dissolved at pH 5 and 4.5, respectively, the structure showed high mean heights suggesting trapped silica gel inside the capsules which may be due to an unsuitable pH or thick shells. However, the dissolution of the core containing 8 layers

• [34]. Certain limitations such as low stability and low EE have been reported in organic and inorganic templates, respectively. Interestingly, the deposition of an additional silica layer through a biomimetic mineralization process onto a protamine/PSS microcapsule formed on a CaCO3 template improved

• have been demonstrated with silica or carbonate cores. The crystallization of CaCO3 from supersaturated solutions results in porous gel-like cores which also play an important role for applications in industry and medicine [32]. Such formation depends on the experimental conditions such as pH, salt

Interfacial charge transfer processes in 2D and 3D semiconducting hybrid perovskites: azobenzene as photoswitchable ligand

• Nicole Fillafer,
• Tobias Seewald,
• Lukas Schmidt-Mende and
• Sebastian Polarz

Beilstein J. Nanotechnol. 2020, 11, 466–479, doi:10.3762/bjnano.11.38

• temperature. The solvent was removed, and the residue was dissolved in ethyl acetate (EA) and methanol (MeOH) (5:1) and filtered over silica gel. The solvent was removed and a yellowish powder was obtained [61]. The product was characterized by using 1H NMR spectroscopy. 1H NMR (400 MHz, DMSO-d6) n = 1: δ

Nanoarchitectonics: bottom-up creation of functional materials and systems

• Katsuhiko Ariga

Beilstein J. Nanotechnol. 2020, 11, 450–452, doi:10.3762/bjnano.11.36

• hydroxide/sepiolite hybrids [31], and cell surface engineering with halloysite-doped silica cell imprints for shape recognition of human cells [32]. In another example, magnetic nanoparticles were attached to microbubble shells for enhanced biomedical imaging [33]. In a final example, the detection of the

Nanoparticles based on the zwitterionic pillar[5]arene and Ag⁺: synthesis, self-assembly and cytotoxicity in the human lung cancer cell line A549

• Dmitriy N. Shurpik,
• Denis A. Sevastyanov,
• Pavel V. Zelenikhin,
• Pavel L. Padnya,
• Vladimir G. Evtugyn,
• Yuriy N. Osin and
• Ivan I. Stoikov

Beilstein J. Nanotechnol. 2020, 11, 421–431, doi:10.3762/bjnano.11.33

• -nitroaniline matrix. The melting points were determined using a Boetius Block apparatus. Additional control of the purity of compounds and monitoring of the reaction were carried out by thin-layer chromatography using Silica G, 200 µm plates, UV 254. Most chemicals were purchased from Aldrich and used as

Interactions at the cell membrane and pathways of internalization of nano-sized materials for nanomedicine

• Valentina Francia,
• Daphne Montizaan and
• Anna Salvati

Beilstein J. Nanotechnol. 2020, 11, 338–353, doi:10.3762/bjnano.11.25

• of 100 nm silica nanoparticles incubated with human serum were found to interact with their corresponding receptors, low-density lipoprotein receptor and Fc-gamma receptor I, respectively [17]. Similarly, lipid nanoparticles were efficiently targeted to the hepatocytes upon adsorption of apoE on

• required to wrap a lipid membrane around a nanoparticle with high aspect ratio [148]. However, also in relation to this aspect, conflicting results were found in which cross-linked poly(ethylene glycol) hydrogels or mesoporous silica particles with higher aspect ratio were internalized quicker and more

• 3) were both taken up by HeLa cells by a combination of clathrin-mediated and caveolae-mediated endocytosis (based on cholesterol and tyrosine kinase dependence) [125]. On the other hand, in another study, the entry of cylindric, worm-like, and spherical silica particles in A549 and RAW264.7 cells

An advanced structural characterization of templated meso-macroporous carbon monoliths by small- and wide-angle scattering techniques

• Felix M. Badaczewski,
• Marc O. Loeh,
• Torben Pfaff,
• Dirk Wallacher,
• Daniel Clemens and
• Bernd M. Smarsly

Beilstein J. Nanotechnol. 2020, 11, 310–322, doi:10.3762/bjnano.11.23

• create meso- or macropores into the carbon system templating approaches have become a routine strategy. One prominent attempt is hard-templating based on silica monoliths with a bimodal pore size distribution (meso- and macropores) and a hierarchical pore network [35][36][37][38]. The SiO2 solid is

• surface area and a high permeability. Due to big macropores the material can achieve high flow rates for separation processes, and the mesopores within the walls of the macropores lead to a high surface area, which is beneficial for adsorption processes [39][40]. Carbon replicas based on silica monoliths

• . In both cases, the hard-templated carbon was exposed to two substantially different temperatures, namely 800 and 3000 °C. This means that two porous carbon materials were treated at 800 and two at 3000 °C. In short, in the hard-templating process the pristine silica monoliths were infiltrated by a

Rational design of block copolymer self-assemblies in photodynamic therapy

• Maxime Demazeau,
• Laure Gibot,
• Anne-Françoise Mingotaud,
• Patricia Vicendo,
• Clément Roux and
• Barbara Lonetti

Beilstein J. Nanotechnol. 2020, 11, 180–212, doi:10.3762/bjnano.11.15

Fabrication of Ag-modified hollow titania spheres via controlled silver diffusion in Ag–TiO₂ core–shell nanostructures

• Bartosz Bartosewicz,
• Malwina Liszewska,
• Bogusław Budner,
• Marta Michalska-Domańska,
• Krzysztof Kopczyński and
• Bartłomiej J. Jankiewicz

Beilstein J. Nanotechnol. 2020, 11, 141–146, doi:10.3762/bjnano.11.12

• fabricated in a multistep process including a two-step hydrothermal treatment [11]. Ag-modified TiO2 HSs showing efficient photocatalysis in the visible-light range were synthesized in a multistep process through a sacrificial core technique using AgBr as the core [12]. A hard-templating method with a silica

Molecular architectonics of DNA for functional nanoarchitectures

• Debasis Ghosh,
• Lakshmi P. Datta and
• Thimmaiah Govindaraju

Beilstein J. Nanotechnol. 2020, 11, 124–140, doi:10.3762/bjnano.11.11

• scaffold embedded with Ru(bpy)32+-conjugated silica nanoparticles. The DNA tetrahedron geometry acted as a capture DNA that repelled the nonspecific DNA entanglement along the ECL platform and stimulated the hybridization of glucose oxidase (GOD) enzyme-conjugated DNA (GOD-S). In a programmable cyclic

The effect of heat treatment on the morphology and mobility of Au nanoparticles

• Sven Oras,
• Sergei Vlassov,
• Simon Vigonski,
• Boris Polyakov,
• Mikk Antsov,
• Vahur Zadin,
• Rünno Lõhmus and
• Karine Mougin

Beilstein J. Nanotechnol. 2020, 11, 61–67, doi:10.3762/bjnano.11.6

• manipulated on a silica substrate with an atomic force microscope (AFM) in tapping mode. Initially, the NPs were immovable by AFM energy dissipation. However, annealed NPs became movable, and less energy was required to displace the NPs annealed at higher temperature. However, after annealing at 800 °C, 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

• (ethylene oxide)-b-poly(acrylic acid) (PEO-b-PAA) and an oligo-chitosan-type polyamine was used as a structure-directing agent to prepare ordered mesoporous silica materials in the work “pH-mediated control over the mesostructure of ordered mesoporous materials templated by polyion complex micelles” [22

• for sensing or corrosion protection. To understand composite formation of a complex hybrid assembly, high quality characterization is paramount. An example is small angle X-ray scattering (SAXS), which was used in the work “Mechanism of silica–lysozyme composite formation unraveled by in situ fast

Mobility of charge carriers in self-assembled monolayers

• Zhihua Fu,
• Tatjana Ladnorg,
• Hartmut Gliemann,
• Alexander Welle,
• Asif Bashir,
• Michael Rohwerder,
• Qiang Zhang,
• Björn Schüpbach,
• Andreas Terfort and
• Christof Wöll

Beilstein J. Nanotechnol. 2019, 10, 2449–2458, doi:10.3762/bjnano.10.235

• aqueous NH4Cl solution was added and the product extracted with dichloromethane. The extract was filtered through a pad of silica, evaporated to dryness and recrystallized from methylcyclohexane, yielding 9.1 g (85%) of a yellow solid. 1H NMR (CDCl3, 400 MHz) δ 8.22 (s, 1H, H-10), 8.20 (s, 1H, H-9), 8.02

• solution (1.0 mol/L in THF, 12 mmol) were added dropwise. Stirring at room temperature was continued for 1 h and then 50 mL of H2O were added. The product was extracted with dichloromethane and filtered through a plug of silica. Evaporation of the volatiles resulted in 2 g of a brownish solid (90%). 1H NMR

• 24 h stirring at room temperature, the mixture was adsorbed onto silica and dried by means of a rotary evaporator. The loaded silica was placed on top of a silica plug and then eluted first with hexanes/dichloromethane 2:1 to remove nonpolar impurities. Then the product was eluted first by

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

• , D-12489 Berlin, Germany Hochschule Darmstadt - University of Applied Sciences, Fachbereich Chemie- und Biotechnologie, Stephanstr. 7, D-64295 Darmstadt, Germany 10.3762/bjnano.10.231 Abstract A concept for the growth of silica shells with a thickness of 5–250 nm onto oleate-coated NaYF4:Yb3+/Er3

• remain constant. Hence, the number of micelles stays constant, and their size is increased to accommodate the growing core–shell particles. Consequently, the formation of core-free silica particles is suppressed. When the negative zeta potential of the particles, which continuously decreased during the

• -core particles are obtained. This strategy can be easily transferred to other nanomaterials for the design of plasmonic nanoconstructs and sensor systems. Keywords: reverse microemulsion; silica coating; stepwise growth; thick shells; upconversion nanoparticles; Introduction Lanthanide-based

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

• Chemistry, School of Basic Sciences, Vels Institute of Science, Technology and Advanced Studies (VISTAS), Chennai 600117, India 10.3762/bjnano.10.214 Abstract The combination of magnetic nanoparticles with a porous silica is a composite that has attracted significant attention for potential multifunctional

• theranostic applications. In this study, 30 wt % CuFe2O4 was impregnated into a matrix of monodispersed spherical hydrophilic silica (HYPS) nanoparticles through a simple dry impregnation technique. The chemotherapy drug cisplatin was loaded through electrostatic equilibrium adsorption over 24 h in normal

• dispersive X-ray (EDX) mapping analysis showed the presence of homogeneous silica particles with nanoclusters of copper ferrite distributed on the HYPS support. Vibrating sample magnetometry (VSM) analysis of CuFe2O4/HYPS showed paramagnetic behavior with a saturated magnetization value of 7.65 emu/g. DRS UV

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

• use; THF used for click reaction was dried over Na/benzophenone and freshly distilled. Thin-layer chromatography (TLC) was performed on Silica Gel 60 F254 plates (Merck) with UV detection (254 and 365 nm) or using appropriate developing solutions. Flash column chromatography was performed on silica