Identifying diverse metal oxide nanomaterials with lethal effects on embryonic zebrafish using machine learning

• Richard Liam Marchese Robinson,
• Haralambos Sarimveis,
• Philip Doganis,
• Xiaodong Jia,
• Marianna Kotzabasaki,
• Christiana Gousiadou,
• Stacey Lynn Harper and
• Terry Wilkins

Beilstein J. Nanotechnol. 2021, 12, 1297–1325, doi:10.3762/bjnano.12.97

• variables related to biological effects, surface chemical composition was encoded using molecular descriptors computed for the gas phase molecules [28][29], with pH value-dependent ionization state reported to have been taken into account in one study [29].) In reality, these molecules are likely to be

• calculating the descriptors at biologically relevant pH values [29], as well as constructing physically realistic representations of the surface structures of coated and uncoated nanomaterials, rather than calculating descriptors for organic surface components as free molecules and substituting dummy values

Impact of electron–phonon coupling on electron transport through T-shaped arrangements of quantum dots in the Kondo regime

• Patryk Florków and
• Stanisław Lipiński

Beilstein J. Nanotechnol. 2021, 12, 1209–1225, doi:10.3762/bjnano.12.89

• embedded in a freestanding GaAs/AlGaAs membrane [44][45][46][47][48]. It has been shown that morphology manipulation of semiconductor QDs such as size, shape, strain distribution, or inhomogenities can influence the coupling strength of electron–phonon (e–ph) interactions [49]. The phononic effects appears

• single occupied orbitals. In consequence, the regions of occurrence of an even number of electrons in the system narrow down or completely disappear with the increase of the strength of e–ph interaction. Fluctuating spin doublets interfering with the wave propagating through a direct path give rise

• , through cotunneling processes, to the spin Fano–Kondo effect. For strong e–ph coupling, the charge ordered ground state of the system appears, and for special ranges of gate voltages and the corresponding values of e–ph coupling the charge Fano–Kondo effect occurs. Model and Formalism We consider two

Morphology-driven gas sensing by fabricated fractals: A review

• Vishal Kamathe and
• Rupali Nagar

Beilstein J. Nanotechnol. 2021, 12, 1187–1208, doi:10.3762/bjnano.12.88

• method [81]. The as-prepared h-BiVO4 structure exhibited high sensitivity towards formaldehyde and ethanol. The formation of hyperbranched structures was found to be a function of different pH values, proton intercalation, and dissolution processes. The sensitivity in case of h-BiVO4 was found to be

Self-assembly of amino acids toward functional biomaterials

• Huan Ren,
• Lifang Wu,
• Lina Tan,
• Yanni Bao,
• Yuchen Ma,
• Yong Jin and
• Qianli Zou

Beilstein J. Nanotechnol. 2021, 12, 1140–1150, doi:10.3762/bjnano.12.85

• nucleotides, can be self-assembled [14]. Proteins are direct functional performers of countless interactions between living organisms and the outside world, and are susceptible to changes in pH value, ionic strength, and temperature [15]. Peptides have similar biocompatibility and diversity as proteins, but

• and pH values [49]. Rizzo et al. studied camptothecin loaded into Fmoc-F hydrogels in the presence of haloalkyl nanotubes. Importantly, this hybrid co-assembly method could not only control the release of camptothecin in the form of active lactone, but also showed significant inhibitory activity on

• phenylalanine to produce hydrogels driven by hydrogen bonds and π–π interactions and to form microfiber three-dimensional networks at 1 wt % and pH 7.4. The microfibers have AIE properties and strong blue emission under an ultraviolet lamp. Ni-terminated hydrogels of NI-Phe exhibit viscoelasticity with a

pH-driven enhancement of anti-tubercular drug loading on iron oxide nanoparticles for drug delivery in macrophages

• Karishma Berta Cotta,
• Sarika Mehra and
• Rajdip Bandyopadhyaya

Beilstein J. Nanotechnol. 2021, 12, 1127–1139, doi:10.3762/bjnano.12.84

• the surrounding pH, drug loading enhancement could be pH dependent. Hence, upon synthesizing IONPs, they were coated with NOR, either at pH 5 (predominantly as cationic, NOR+) or at pH 10 (predominantly as anionic, NOR−). We observed that, drug loading at pH 5 exceeded that at pH 10 by 4.7–5.7 times

• . Furthermore, only the former (pH 5 system) exhibited a desirable slower drug release profile, compared to the free drug. NOR-coated IONPs also enable a 22 times higher drug accumulation in macrophages, compared to identical extracellular concentrations of the free drug. Thus, lowering the drug coating pH to 5

• ]. Furthermore, their interaction with IONPs may be via carboxylate groups, amine groups or by neither [27]. pH variations thus can play a key role in promoting interactions between amino acids and metal oxide surfaces [29]. NOR has also been reported to form stable complexes with Fe2+/3+ [22]. It was also

Use of nanosystems to improve the anticancer effects of curcumin

• Andrea M. Araya-Sibaja,
• Norma J. Salazar-López,
• Krissia Wilhelm Romero,
• José R. Vega-Baudrit,
• J. Abraham Domínguez-Avila,
• Carlos A. Velázquez Contreras,
• Ramón E. Robles-Zepeda,
• Mirtha Navarro-Hoyos and
• Gustavo A. González-Aguilar

Beilstein J. Nanotechnol. 2021, 12, 1047–1062, doi:10.3762/bjnano.12.78

• subcellular anticancer therapies which carry the drug and better focus it on the intended target. They are also able to contain molecules that respond to endogenous (tumor microenvironment, including redox potential, pH, enzymes, ions, or biomolecules) and/or exogenous stimuli (light, electromagnetic fields

• , instability at a physiological pH, and rapid metabolization [52]. Although nanocrystals make it possible to improve the solubility of CUR, it has been reported that this type of nanosystem can have certain stability problems, which may compromise the ability to ensure a consistent dosage [53]. Nanococrystals

• the surface of CUR nanococrystals with hyaluronic acid to increase its hydrophilicity, which resulted in a better biodistribution. They reported an advantage in the release profile as a function of pH due to a lower CUR release at pH 7.4 (40%) as compared to the acidic pH (pH 5, 80%) which is

An overview of microneedle applications, materials, and fabrication methods

• Zahra Faraji Rad,
• Philip D. Prewett and
• Graham J. Davies

Beilstein J. Nanotechnol. 2021, 12, 1034–1046, doi:10.3762/bjnano.12.77

• biodegradable and biocompatible nature. It was first shown in 1995 that, by introducing porosity into silicon, the material behaviour can change to provide a bioactive and even resorbable material [92]. Unlike bulk silicon, in alkalescent media (pH ≈ 7.5), porous silicon is broken down by hydrolysis in living

Revealing the formation mechanism and band gap tuning of Sb₂S₃ nanoparticles

• Maximilian Joschko,
• Franck Yvan Fotue Wafo,
• Christina Malsi,
• Danilo Kisić,
• Ivana Validžić and
• Christina Graf

Beilstein J. Nanotechnol. 2021, 12, 1021–1033, doi:10.3762/bjnano.12.76

• German Academic Exchange Service (DAAD) within the PPP Serbia program (grant 57447826). This work was supported by a fellowship of the Platform for Ph. D. students of the Technical University of Darmstadt and the Darmstadt University of Applied Sciences.

Uniform arrays of gold nanoelectrodes with tuneable recess depth

• Elena O. Gordeeva,
• Ilya V. Roslyakov,
• Alexey P. Leontiev,
• Alexey A. Klimenko and
• Kirill S. Napolskii

Beilstein J. Nanotechnol. 2021, 12, 957–964, doi:10.3762/bjnano.12.72

• a long-term Au electrodeposition from acidic electrolyte with pH < 5 leads to the degradation of the AAO template, characterized by a low chemical stability in the as-prepared amorphous state [28][29]. Thus, the proposed design and strategy for the fabrication of the Au NEAs include the formation of

The role of deep eutectic solvents and carrageenan in synthesizing biocompatible anisotropic metal nanoparticles

• Nabojit Das,
• Akash Kumar and
• Raja Gopal Rayavarapu

Beilstein J. Nanotechnol. 2021, 12, 924–938, doi:10.3762/bjnano.12.69

• aggregation and sedimentation above pH 5 [117]. The stability was enhanced upon adhesion of carrageenan to the nanoparticle surface rendering it negatively charged. Although there are little reports on using carrageenan as a safe and sustainable component for synthesizing plasmonic metal nanomaterials, the

Modification of a SERS-active Ag surface to promote adsorption of charged analytes: effect of Cu²⁺ ions

• Bahdan V. Ranishenka,
• Andrei Yu. Panarin,
• Irina A. Chelnokova,
• Sergei N. Terekhov,
• Peter Mojzes and
• Vadim V. Shmanai

Beilstein J. Nanotechnol. 2021, 12, 902–912, doi:10.3762/bjnano.12.67

• ). Thiocholine was generated in situ by basic hydrolysis of its acetyl ether in sodium carbonate buffer at pH 10.8. The supports were soaked for 30 min in the corresponding reagent solution, washed with deionized water, and dried. Treatment with doubly charged metal ions was carried out in 5 mg/mL Cu sulfate or

Comprehensive review on ultrasound-responsive theranostic nanomaterials: mechanisms, structures and medical applications

• Sepand Tehrani Fateh,
• Lida Moradi,
• Elmira Kohan,
• Michael R. Hamblin and
• Amin Shiralizadeh Dezfuli

Beilstein J. Nanotechnol. 2021, 12, 808–862, doi:10.3762/bjnano.12.64

• , pH changes, temperature changes) or external (light, heat, magnetic fields, ultrasound). Theranostic nanomaterials can respond by producing an imaging signal and/or a therapeutic effect, which frequently involves cell death. Since ultrasound (US) is already well established as a clinical imaging

• temperature, pH, enzyme, redox potential, ionic strength, or solvent composition of the media. Other stimuli are external, such as heat, light, electric field, magnetic field, or ultrasound (US) [5][6][7]. Designing such single, dual, or multi-stimulus-responsive smart delivery vehicles provides an

9.1% efficient zinc oxide/silicon solar cells on a 50 μm thick Si absorber

• Rafal Pietruszka,
• Bartlomiej S. Witkowski,
• Monika Ozga,
• Katarzyna Gwozdz,
• Ewa Placzek-Popko and
• Marek Godlewski

Beilstein J. Nanotechnol. 2021, 12, 766–774, doi:10.3762/bjnano.12.60

• water were used as zinc and oxygen precursors, respectively. After growth of the ZnO nanoseeds, the samples were transferred to the HT reactor. The solution for hydrothermal growth was prepared by dissolving 3 g of zinc acetate (CAS Number 557-34-6) in 70 mL of deionized water, adjusted to pH 7.5 by a 1

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

• has a better development prospect. Patino et al. [43] combined DNA nanoswitches with urease-powered micromotors to achieve the goal of swimming and sensing the pH value of the environment. In this study, the urease-powered micromotor served two functions. It detected changes in the pH value through

• FRET imaging while propelling the switches. The entire self-actuation process is realized by urease-mediated conversion of urea into ammonia and carbon dioxide. Unlike traditional nanoprobes, DNA nanoswitches can perform pH value measurements within a few microseconds. This research is a big step

• MNP concentrations (1%, 3%, and 5%) under a rotating magnetic field. Each dot represents the average velocity for five different ISMEs with hexagram shapes ± standard error of the mean (s.e.m.). (d) a) Images of the ISME with encapsulated MNPs during folding in response to a pH change. Scale bar: 500

Recent progress in magnetic applications for micro- and nanorobots

• Ke Xu,
• Shuang Xu and
• Fanan Wei

Beilstein J. Nanotechnol. 2021, 12, 744–755, doi:10.3762/bjnano.12.58

• ]. Wang et al. [83] successfully fabricated a biocompatible and pH-responsive magnetic helical microstructure coated with zinc-based MOF and zeolite imidazole framework-8 (ZIF-8). They also developed a helical swimmer with 2PP, also called artificial bacterial flagella, as shown in Figure 2. In order to

Nanogenerator-based self-powered sensors for data collection

• Yicheng Shao,
• Maoliang Shen,
• Yuankai Zhou,
• Xin Cui,
• Lijie Li and
• Yan Zhang

Beilstein J. Nanotechnol. 2021, 12, 680–693, doi:10.3762/bjnano.12.54

• , portable, easy-to-deploy, and low-cost TENGs are novel devices for water quality monitoring. Zhou et al. proposed the use of waste materials to make an arc-shaped TENG (AS-TENG) [15]. The AS-TENG can provide energy for a pH sensor in water. The system can trigger an alarm when the pH value is lower than 5

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

• drug abuse [21]. Animal experiments demonstrated Ag accumulation in the liver, kidneys, brain, and testis after oral exposure to AgNPs; however, the chemical form of Ag remained undefined in these cases [22]. In media of high ionic strength and low pH the AgNPs aggregate and/or dissolve [23]. Under

• ]. Upon oral administration, AgNPs are first exposed to saliva and then to gastric fluid. These two media are characterized by different pH values, ranging from 6.2 to 7.6 in saliva or from 1.5 to 3.5 in gastric fluid, which may significantly affect AgNP dissolution. Moreover, the lining oral mucosa may

• residence time [9][15][26]. In the intestinal environment, a higher pH may slow down the loss of AgNPs [10]. Indeed, there is even evidence of agglomerates breaking down and releasing original AgNPs [32]. In both environments, the dissolved Ag may be released and may interact with many molecules. Although

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

• of ethylene glycol, homogenized by ultrasound for 10 min, and then stirred on a magnetic stirrer for 15 min. Then, without stopping stirring, a water solution of H2PtCl6 (TU 2612-034-00205067-2003, Pt mass fraction of 37.6%, Aurat, Russia) was introduced into the suspension and the pH was adjusted to

On the stability of microwave-fabricated SERS substrates – chemical and morphological considerations

• Limin Wang,
• Aisha Adebola Womiloju,
• Christiane Höppener,
• Ulrich S. Schubert and
• Stephanie Hoeppener

Beilstein J. Nanotechnol. 2021, 12, 541–551, doi:10.3762/bjnano.12.44

• sulfoxide (DMSO) treatment completely preserved or even slightly improved the Raman enhancement capabilities. SERS substrates immersed into phosphate-buffered saline (PBS) solutions were observed to be rather instable in low and neutral pH buffer solutions. Other buffer systems showed less severe influences

• on the SERS activity of the substrates and a carbonate buffer at pH 10 was found to even improve SERS performance. This study represents a guideline on the stability of microwave-fabricated SERS substrates or other SERS substrates consisting of non-stabilized silver nanoparticles for the application

• analytics. As such, our studies were consequently expanded to investigate the influence of several buffer media commonly used in biological applications on the performance of the SERS substrates. These media frequently contain a complex mixture of different compounds and also have different pH values. The

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

• nanomaterials (ENMs), which could profoundly influence their biological effects, is not well understood. After uptake into phagolysosomes, which have a pH value of ca. 4.5, there is the potential for dissolution, changing the physicochemical, and potentially the biological, identity of ENMs. Nanoceria are a

• were added to 1.5 M ammonium hydroxide, stirred, and autoclaved for 24 h at 50 °C then 24 h at 80 °C. The product was dialyzed against 110 mM pH 7.4 citric acid for 120 h, replacing the dialysate every 24 h, then dialyzed against DI water to remove citric acid and ionic cerium for an additional 72 h

• above. The primary particle diameter was estimated from 100 particles. Nanoceria dissolution The continuous flow system has been described [36][37]. It consists of phagolysosomal simulant fluid (Aleks Stefaniak’s PSF medium at pH 4.5 [38]), the flow-through cell, a flow regulating pump, and an

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

• , such as pH, dissolved oxygen, and zeta potential (ZP) [51][52][53]. The storage temperature is a critical factor that controls the percentage of oxidative dissolution of AgNPs. The higher the temperature, the greater the speed of the dissolution reaction [54][55]. Kittler et al. studied the dissolution

• of 50 nm AgNPs dispersed in water at various temperatures and observed that the release of Ag+ was ≈5% at 5 °C, ≈50% at 25 °C, and ≈90% at 37 °C. The oxidative dissolution of AgNPs involves reactions with protons (H+) and dissolved O2. The dissolution of AgNPs is favorable under an acidic pH and can

• be described by a first-order kinetic reaction, according to Equation 1 [56]. Experimental studies have shown that the decrease in pH generally increases the dissolution kinetics [51][55][57]. Liu and Hurt studied the dissolution of AgNPs in buffered solutions (acetate and borate buffer) in a pH

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

• towards fusion oncoproteins involved in proliferative or anti-apoptotic signaling pathways [13]. For instance, more than 90% of the cases of chronic myelogenous leukemia (CML) are characterized by a unique chromosomal abnormality known as Philadelphia (Ph) chromosome [14]. This abnormality is a reciprocal

• chromosomal translocation between the long arms of chromosomes 9 and 22, designated as t(9;22)(q34;q11), creating a derivative 9q+ and a shortened 22q Ph chromosome. The chimeric Ph chromosome generates the BCR-ABL1 gene by fusion of the Abelson murine leukemia (ABL1) gene from chromosome 9 with the

• carrier structure. I-motifs are four-stranded quadruplex structures formed by cytosine-rich DNA that posses unique pH-sensitive characteristics. The double-stranded complementary DNA responds to a drop of the pH value in the environment by forming i-motifs and releasing the intercalated doxorubicin. The

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

• be obtained by utilizing external stimuli, such as pH value, light, or ultrasound, to deliver the anti-cancerous drug into tumor tissue with spatial and temporal control [14]. Photothermal therapy (PTT) is an emerging minimally invasive cancer therapy. It can efficiently induce cytotoxicity by

• their biocompatibility and dispersion at physiological pH values. The positive CTAB layer on the GNR surface facilitates electrostatic adsorption of anionic compounds, such as poly(sodium 4-styrenesulfonate) (PSS), which ultimately facilitates electrostatic interaction with cationic anticancerous drugs

• ]. The uniform GNRs were synthesized with an aspect ratio of 4.3 (26 ± 2 nm in length and 6 ± 3 nm in width), by keeping pH value (pH 3) and temperature (T = 28 °C) constant. The prepared GNR suspension has a surplus of cytotoxic CTAB, which was removed by repetitive cycles of centrifugation and re

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

• normalization of data. Western blotting Cells were lysed in buffer containing 50 mM Tris/HCl, pH 7.4, 150 mM NaCl, 1% Triton X-100, and 1 mM EDTA, supplemented with protease inhibitor mix (Serva, BioTech, Ltd., Slovakia). After determining the protein concentration using the Bradford assay, equal amounts 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

• using the SurPASS™ system (Anton Paar, Ostfildern, Germany) to determine the surface potential. Au- and PPAAm-modified titanium substrates were placed in pairs in the measuring chamber with a gap height of 100 μm. The streaming potential was measured at pH 6.5 to 8.0, at 150 mbar in a 1 mM KCl solution

• (VWR International, Darmstadt, Germany). Zeta potential values were determined with the associated software Attract 2.1 (Anton Paar, Ostfildern, Germany) according to the Helmholtz–Smoluchowski equation. Zeta potential values at pH 7.4 were calculated with the function “linear regression” using the