| 1. |
- Askari, Sadegh, et al.
(author)
-
Plasma-based processes for planar and 3D surface patterning of functional nanoparticles
- 2019
-
In: Journal of nanoparticle research. - : SPRINGER. - 1388-0764 .- 1572-896X. ; 21:11
-
Journal article (peer-reviewed)abstract
- We present a gas-phase process for surface patterning and 3D self-assembly of nanoparticles (NPs) of functional materials such as metals, oxides, and nitrides. The method relies on electrostatic assembly of free-flying NPs with unipolar charge produced in plasma sources. We demonstrate the capability of the process in self-assembly of NPs, with the size in the range 10-60 nm, into arrays of free-standing 3D microstructures with complex morphologies. Considering that the plasma nanoparticle sources are compatible with synthesis of a large library of material NPs, the process introduces a novel approach for 3D printing of various functional NPs, high-precision device integration of NPs on sub-micrometer scales, and large-area parallel surface patterning of NPs.
|
|
| 2. |
- Boholm, Åsa, 1953, et al.
(author)
-
What is the problem? A literature review on challenges facing the communication of nanotechnology to the public
- 2019
-
In: Journal of nanoparticle research. - : Springer Science and Business Media LLC. - 1388-0764 .- 1572-896X. ; 21:4
-
Journal article (peer-reviewed)abstract
- Ethical and societal issues concerning justice, safety, risks, and benefits are well-established topics in the discourses of nanotechnology innovation and development. That nanotechnology innovation should be socially and ethically responsible is generally accepted by scientists, policymakers, regulators, and industry, and the idea of public involvement and communication is part and parcel of the conceptualization of responsible technology development. This paper systematically reviews the social science research literature accumulated between 2002 and 2018 on the communication of nanotechnology. A critical and constructivist perspective on policy problems guides the analysis. Two questions are asked of this literature: what problems are identified regarding the communication of nanotechnology to the public? How can these problems be managed and/or resolved? Three different problem themes are identified: the public, societal institutions, and nanotechnology itself. While for some identified problems, there are corresponding solutions; in other instances, there is little alignment between problems and solutions. In conclusion, the paper recommends that in communicating nanotechnology to the public: (i) the objectives of communication should be defined; (ii) previous research should be used responsibly; (iii) communication strategies should be adapted to the context; and (iv) effort should not be spent trying to develop a generic framework for communication.
|
|
| 3. |
- Bundschuh, Mirco
(author)
-
Synthesis, characterization, and ecotoxicity of CeO2 nanoparticles with differing properties
- 2016
-
In: Journal of Nanoparticle Research. - : Springer Science and Business Media LLC. - 1388-0764 .- 1572-896X. ; 18
-
Journal article (peer-reviewed)abstract
- CeO2 nanoparticles with various characteristics find an increasing number of applications in the electronic, medical, and other industries and are therefore likely released in the environment. This calls for investigations linking the physicochemical properties of these particles with their potential environmental impacts. In this study, CeO2 nanoparticle powders were prepared using three different precursors [Ce(NO3)(3), CeCl3, and Ce(CH3COO)(3)] and annealing temperatures (300, 500, and 700 degrees C). This procedure resulted in nine different types of nanoparticles with differing size (5-90 nm), morphology, surface Ce3+/Ce4+ ratio, and slightly different crystal structures as characterized using transmission electron microscopy, dynamic light scattering, X-ray photoelectron spectroscopy, and X-ray diffraction measurements with Rietveld refinement. These CeO2 nanoparticles underwent toxicity testing at concentrations up to 64 mg L-1 using Daphnia magna. Toxic effects were observed for three particle types with EC50 values between 5 and 64 mg L-1. No clear correlation was observed between the physicochemical properties (size, shape, oxygen occupancy, Ce3+/Ce4+ ratio) of the nanoparticles and their toxicity. However, toxicity was correlated with the amount of Ce remaining suspended in the test medium after 24 h. This indicated that toxic effects may depend on the colloidal stability of CeO2 nanoparticles during the first day of exposure. Therefore, being readily suspended and remaining stable for several days in the aquatic media increases the likelihood that CeO2 nanoparticles will cause unwanted adverse effects.
|
|
| 4. |
- Danielsson, Karin, et al.
(author)
-
Influence of organic molecules on the aggregation of TiO2 nanoparticles in acidic conditions
- 2017
-
In: Journal of nanoparticle research. - : Springer Science and Business Media LLC. - 1388-0764 .- 1572-896X. ; 19
-
Journal article (peer-reviewed)abstract
- © 2017, The Author(s).Engineered nanoparticles released into the environment may interact with natural organic matter (NOM). Surface complexation affects the surface potential, which in turn may lead to aggregation of the particles. Aggregation of synthetic TiO2 (anatase) nanoparticles in aqueous suspension was investigated at pH 2.8 as a function of time in the presence of various organic molecules and Suwannee River fulvic acid (SRFA), using dynamic light scattering (DLS) and high-resolution transmission electron microscopy (TEM). Results showed that the average hydrodynamic diameter and ζ-potential were dependent on both concentration and molecular structure of the organic molecule. Results were also compared with those of quantitative batch adsorption experiments. Further, a time study of the aggregation of TiO2 nanoparticles in the presence of 2,3-dihydroxybenzoic acid (2,3-DHBA) and SRFA, respectively, was performed in order to observe changes in ζ-potential and particle size over a time period of 9months. In the 2,3-DHBA-TiO2 system, ζ-potentials decreased with time resulting in charge neutralization and/or inversion depending on ligand concentration. Aggregate sizes increased initially to the micrometer size range, followed by disaggregation after several months. No or very little interaction between SRFA and TiO2 occurred at the lowest concentrations tested. However, at the higher concentrations of SRFA, there was an increase in both aggregate size and the amount of SRFA adsorbed to the TiO2 surface. This was in correlation with the ζ-potential that decreased with increased SRFA concentration, leading to destabilization of the system. These results stress the importance of performing studies over both short and long time periods to better understand and predict the long-term effects of nanoparticles in the environment.
|
|
| 5. |
- Dou, Yangpeng, et al.
(author)
-
Effects of reducibility of graphene oxide nanosheets on preparation of AgNPs/GO nanocomposites and their electrocatalytic performance
- 2015
-
In: Journal of nanoparticle research. - : Springer Science and Business Media LLC. - 1388-0764 .- 1572-896X. ; 17:12, s. 1-10
-
Journal article (peer-reviewed)abstract
- Silver nanoparticles/graphene oxide (AgNPs/GO) nanocomposites were prepared in a solution of AgNO3 and GO. The GO serves not only as a reductant but also as a substrate to support the as-reduced silver nanoparticles. The reducibility of GO was investigated by analyzing the influence factors such as pH, duration, the reaction temperature, and the weight ratio of AgNO3 and GO in the AgNP/GO nanocomposite mixture, which were evaluated by the UV–vis absorption spectroscopy. The results demonstrated that Ag nanoparticles with an average diameter of 5–10 nm were uniformly dispersed on the surface of GO nanosheets under the optimum synthesis conditions of pH between 8 and 11, weight ratio of AgNO3 and GO between 55 % and 60 %, and at 80 °C for 6 h. Moreover, the obtained AgNPs/GO nanocomposites exhibit good electrocatalytic activity for the reduction of p-nitrophenol to 4-(hydroxyamino) phenol.
|
|
| 6. |
- Ekeroth, Sebastian, et al.
(author)
-
Growth of semi-coherent Ni and NiO dual-phase nanoparticles using hollow cathode sputtering
- 2019
-
In: Journal of nanoparticle research. - : SPRINGER. - 1388-0764 .- 1572-896X. ; 21:2
-
Journal article (peer-reviewed)abstract
- Anisotropic heterogenous Ni/NiO nanoparticles with controlled compositions are grown using a high-power pulsed hollow cathode process. These novel particles can be tuned to consist of single-phase Ni via two-phase Ni/NiO to fully oxidized NiO, with a size range of 5-25 nm for individual crystals. A novelty of this approach is the ability to assemble multiple particles of Ni and NiO into a single complex structure, increasing the Ni-NiO interface density. This type of particle growth is not seen before and is explained to be due to the fact that the process operates in a single-step approach, where both Ni and O can arrive at the formed nanoparticle nuclei and aid in the continuous particle growth. The finished particle will then be a consequence of the initially formed crystal, as well as the arrival rate ratio of the two species. These particles hold great potential for applications in fields, such as electro- and photocatalysis, where the ability to control the level of oxidation and/or interface density is of great importance.
|
|
| 7. |
- Ekeroth, Sebastian, 1988-, et al.
(author)
-
Impact of nanoparticle magnetization on the 3D formation of dual-phase Ni/NiO nanoparticle-based nanotrusses
- 2019
-
In: Journal of nanoparticle research. - : Springer-Verlag New York. - 1388-0764 .- 1572-896X. ; 21:11
-
Journal article (peer-reviewed)abstract
- Magnetic nanoparticles with average size 30 nm were utilized to build three-dimensional framework structures—nanotrusses. In dual-phase Ni/NiO nanoparticles, there is a strong correlation between the amount of magnetic Ni and the final size and shape of the nanotruss. As it decreases, the length of the individual nanowires within the trusses also decreases, caused by a higher degree of branching of the wires. The position and orientation of the non-magnetic material within the truss structure was also investigated for the different phase compositions. For lower concentrations of NiO phase, the electrically conducting Ni-wire framework is maintained through the preferential bonding between the Ni crystals. For larger concentrations of NiO phase, the Ni-wire framework is interrupted by the NiO. The ability to use nanoparticles that are only partly oxidized in the growth of nanotruss structures is of great importance. It opens the possibility for using not only magnetic metals such as pure Ni, Fe, and Co, but also to use dual-phase nanoparticles that can strongly increase the efficiency of e.g. catalytic electrodes and fuel cells.
|
|
| 8. |
- Fakhoury, Isabelle, et al.
(author)
-
Uptake, delivery, and anticancer activity of thymoquinone nanoparticles in breast cancer cells
- 2016
-
In: Journal of nanoparticle research. - : Springer Science and Business Media LLC. - 1388-0764 .- 1572-896X. ; 18:7
-
Journal article (peer-reviewed)abstract
- Thymoquinone (TQ) is a promising anticancer molecule but its development is hindered by its limited bioavailability. Drug encapsulation is commonly used to overcome low drug solubility, limited bioavailability, and nonspecific targeting. In this project, TQ nanoparticles (TQ-NP) were synthesized and characterized. The cytotoxicity of the NP was investigated in nontumorigenic MCF-10-A breast cells, while the uptake, distribution, as well as the anticancer potential were investigated in MCF-7 and MDA-MB-231 breast cancer cells. Flash Nanoprecipitation and dynamic light scattering coupled with scanning electron microscopy were used to prepare and characterize TQ-NP prior to measuring their anticancer potential by MTT assay. The uptake and subcellular intake of TQ-NP were evaluated by fluorometry and confocal microscopy. TQ-NP were stable with a hydrodynamic average diameter size around 100 nm. Entrapment efficiency and loading content of TQ-NP were high (around 80 and 50 %, respectively). In vitro, TQ-NP had equal or enhanced anticancer activity effects compared to TQ in MCF-7 and aggressive MDA-MB-231 breast cancer cells, respectively, with no significant cytotoxicity of the blank NP. In addition, TQ and TQ-NP were relatively nontoxic to MCF-10-A normal breast cells. TQ-NP uptake mechanism was both time and concentration dependent. Treatment with inhibitors of endocytosis suggested the involvement of caveolin in TQ-NP uptake. This was further confirmed by subcellular localization findings showing the colocalization of TQ-NP with caveolin and transferrin as well as with the early and late markers of endocytosis. Altogether, the results describe an approach for the enhancement of TQ anticancer activity and uncover the mechanisms behind cell-TQ-NP interaction.
|
|
| 9. |
- Gunnarsson, Rickard, et al.
(author)
-
Synthesis of titanium-oxide nanoparticles with size and stoichiometry control
- 2015
-
In: Journal of nanoparticle research. - : Springer Verlag (Germany). - 1388-0764 .- 1572-896X. ; 17:9, s. 353-
-
Journal article (peer-reviewed)abstract
- Ti-O nanoparticles have been synthesized via hollow cathode sputtering in an Ar-O-2 atmosphere using high power pulsing. It is shown that the stoichiometry and the size of the nanoparticles can be varied independently, the former through controlling the O-2 gas flow and the latter by the independent biasing of two separate anodes in the growth zone. Nanoparticles with diameters in the range of 25-75 nm, and with different Ti-O compositions and crystalline phases, have been synthesized.
|
|
| 10. |
- Hedayati, Maryeh, et al.
(author)
-
Transport and retention of carbon-based engineered and natural nanoparticles through saturated porous media
- 2016
-
In: Journal of nanoparticle research. - : Springer. - 1388-0764 .- 1572-896X. ; 18:3
-
Journal article (peer-reviewed)abstract
- Carbon-based engineered nanoparticles have been widely used due to their small size and unique physical and chemical properties. At the same time, the toxic effects of these nanoparticles on human and fish cells have also been observed; therefore, their release and distribution into the surface and subsurface environment is a subject of concern. The aim of this research is to evaluate and compare the transports and retentions of two types of engineered nanoparticles (multiwalled carbon nanotubes and C-60) and the natural carbon nanoparticles collected from a fire accident. Several laboratory experiments were conducted to observe the transport behavior of nanoparticles through a column packed with silica sand. The column experiments were intended to monitor the effect of ionic strength on transport of nanoparticles as a function of their shapes. It was observed that the mobilities of both types of engineered nanoparticles were reduced with the increasing ionic strength from 1.34 to 60 mM. However, at ionic strengths up to 10.89 mM, spherical nanoparticles were more mobile than cylindrical nanoparticles, but the mobility of the cylindrical nanoparticles became significantly higher than spherical nanoparticles at the ionic strength of 60 mM. In comparison with natural fire-born nanoparticles, both types of engineered nanoparticles were much less mobile under the selected experimental condition in this study. Furthermore, inverse modeling was used to calculate parameters such as attachment efficiency, the longitudinal dispersivity, and capacity of the solid phase for the attachment of nanoparticles. The results indicate that the combination of the shape and the solution chemistry of the NPs are responsible for the transport and the retention of nanoparticles in natural environment; however, fire-burned nanoparticles can be highly mobile at the natural groundwater chemistry.
|
|
| 11. |
- Larsson, Simon, 1982, et al.
(author)
-
Expert stakeholders’ perception of nanotechnology: risk, benefit, knowledge, and regulation
- 2019
-
In: Journal of nanoparticle research. - : Springer Science and Business Media LLC. - 1388-0764 .- 1572-896X. ; 21:57
-
Journal article (peer-reviewed)abstract
- This study is positioned in a multidisciplinary research field addressing questions of innovation, foresight, risk perception, regulation, and the role of stakeholder experts as regards nanomaterials and nanotechnology. Nanotechnology is an innovative scientific field with many potential societal benefits but also high uncertainty about risks to human health and the environment. This study is based on a survey distributed to a sample of 237 expert stakeholders in Sweden working in the field of nanotechnology innovation and regulation. The sample comprises experts in both industry and government organizations. The paper explores the expert’s assessment of benefits, risks, and their views of nanotechnology regulation. The experts generally agreed on the need for further regulation of nanotechnology, although they differed in their support for different regulatory measures. Support for government regulation was increased by greater perceived risk and by ethical concerns, while perceived benefit decreased support for government regulation. If nanotechnology was important for the respondent’s organization of affiliation, support for government regulation decreased. Experts in government organizations were more in favor of stronger government regulation, perceived higher risks, and were more concerned about the ethical implications of nanotechnology than were the industry experts. While previous research has discussed views of experts, as well as comparing the attitudes of the general public with experts, this study contributes to the field by analyzing and identifying differences between industry experts and experts working in government.
|
|
| 12. |
- Liang, Lijun, et al.
(author)
-
Translocation mechanism of C-60 and C-60 derivations across a cell membrane
- 2016
-
In: Journal of nanoparticle research. - : Springer. - 1388-0764 .- 1572-896X. ; 18:11
-
Journal article (peer-reviewed)abstract
- Carbon-based nanoparticles (NPs) such as fullerenes and nanotubes have been extensively studied for drug delivery in recent years. The permeation process of fullerene and its derivative molecules through membrane is essential to the utilization of fullerene-based drug delivery system, but the mechanism and the dynamics of permeation through cell membrane are still unclear. In this study, coarse-grained molecular dynamics simulations were performed to investigate the permeation process of functionalized fullerene molecules (ca. 0.72 nm) through the membrane. Our results show that single functionalized fullerene molecule in such nanoscale could permeate the lipid membrane in micro-second time scale. Pristine C-60 molecules prefer to aggregate into several small clusters while C60OH15 molecules could aggregate into one big cluster to permeate through the lipid membrane. After permeation of C-60 or its derivatives into membrane, all C-60 and C60OH15 molecules disaggregated and monodispersed in the lipid membrane.
|
|
| 13. |
- Pradhan, Sulena, et al.
(author)
-
Effect of sonication on particle dispersion, administered dose and metal release of non-functionalized, non-inert metal nanoparticles
- 2016
-
In: Journal of nanoparticle research. - : Springer. - 1388-0764 .- 1572-896X. ; 18:9
-
Journal article (peer-reviewed)abstract
- In this study, we elucidate the effect of different sonication techniques to efficiently prepare particle dispersions from selected non-functionalized NPs (Cu, Al, Mn, ZnO), and corresponding consequences on the particle dose, surface charge and release of metals. Probe sonication was shown to be the preferred method for dispersing non-inert, non-functionalized metal NPs (Cu, Mn, Al). However, rapid sedimentation during sonication resulted in differences between the real and the administered doses in the order of 30–80 % when sonicating in 1 and 2.56 g/L NP stock solutions. After sonication, extensive agglomeration of the metal NPs resulted in rapid sedimentation of all particles. DLVO calculations supported these findings, showing the strong van der Waals forces of the metal NPs to result in significant NP agglomeration. Metal release from the metal NPs was slightly increased by increased sonication. The addition of a stabilizing agent (bovine serum albumin) had an accelerating effect on the release of metals in sonicated solutions. For Cu and Mn NPs, the extent of particle dissolution increased from <1.6 to ~5 % after sonication for 15 min. A prolonged sonication time (3–15 min) had negligible effects on the zeta potential of the studied NPs. In all, it is shown that it is of utmost importance to carefully investigate how sonication influences the physico-chemical properties of dispersed metal NPs. This should be considered in nanotoxicology investigations of metal NPs. Graphical Abstract: [Figure not available: see fulltext.]
|
|
| 14. |
- Riccò, R., et al.
(author)
-
Ultra-small dye-doped silica nanoparticles via modified sol-gel technique
- 2018
-
In: Journal of nanoparticle research. - : Springer. - 1388-0764 .- 1572-896X. ; 20:5
-
Journal article (peer-reviewed)abstract
- In modern biosensing and imaging, fluorescence-based methods constitute the most diffused approach to achieve optimal detection of analytes, both in solution and on the single-particle level. Despite the huge progresses made in recent decades in the development of plasmonic biosensors and label-free sensing techniques, fluorescent molecules remain the most commonly used contrast agents to date for commercial imaging and detection methods. However, they exhibit low stability, can be difficult to functionalise, and often result in a low signal-to-noise ratio. Thus, embedding fluorescent probes into robust and bio-compatible materials, such as silica nanoparticles, can substantially enhance the detection limit and dramatically increase the sensitivity. In this work, ultra-small fluorescent silica nanoparticles (NPs) for optical biosensing applications were doped with a fluorescent dye, using simple water-based sol-gel approaches based on the classical Stöber procedure. By systematically modulating reaction parameters, controllable size tuning of particle diameters as low as 10 nm was achieved. Particles morphology and optical response were evaluated showing a possible single-molecule behaviour, without employing microemulsion methods to achieve similar results.
|
|
| 15. |
- Svensson, Christian, et al.
(author)
-
Validation of an air–liquid interface toxicological set-up using Cu, Pd, and Ag well-characterized nanostructured aggregates and spheres
- 2016
-
In: Journal of Nanoparticle Research. - : Springer Science and Business Media LLC. - 1388-0764 .- 1572-896X. ; 18:4
-
Journal article (peer-reviewed)abstract
- Abstract: Systems for studying the toxicity of metal aggregates on the airways are normally not suited for evaluating the effects of individual particle characteristics. This study validates a set-up for toxicological studies of metal aggregates using an air–liquid interface approach. The set-up used a spark discharge generator capable of generating aerosol metal aggregate particles and sintered near spheres. The set-up also contained an exposure chamber, The Nano Aerosol Chamber for In Vitro Toxicity (NACIVT). The system facilitates online characterization capabilities of mass mobility, mass concentration, and number size distribution to determine the exposure. By dilution, the desired exposure level was controlled. Primary and cancerous airway cells were exposed to copper (Cu), palladium (Pd), and silver (Ag) aggregates, 50–150 nm in median diameter. The aggregates were composed of primary particles 2, respectively, were achieved. Viability was measured by WST-1 assay, cytokines (Il-6, Il-8, TNF-a, MCP) by Luminex technology. Statistically significant effects and dose response on cytokine expression were observed for SAEC cells after exposure to Cu, Pd, or Ag particles. Also, a positive dose response was observed for SAEC viability after Cu exposure. For A549 cells, statistically significant effects on viability were observed after exposure to Cu and Pd particles. The set-up produced a stable flow of aerosol particles with an exposure and dose expressed in terms of number, mass, and surface area. Exposure-related effects on the airway cellular models could be asserted. Graphical Abstract: [Figure not available: see fulltext.]
|
|
| 16. |
|
|
