1. |
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2. |
- Cappellini, Francesca, et al.
(författare)
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Dry Generation of CeO2 Nanoparticles and Deposition onto a Co-Culture of A549 and THP-1 Cells in Air-Liquid Interface-Dosimetry Considerations and Comparison to Submerged Exposure
- 2020
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Ingår i: Nanomaterials. - : MDPI AG. - 2079-4991. ; 10:4
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Tidskriftsartikel (refereegranskat)abstract
- Relevant in vitro assays that can simulate exposure to nanoparticles (NPs) via inhalation are urgently needed. Presently, the most common method employed is to expose lung cells under submerged conditions, but the cellular responses to NPs under such conditions might differ from those observed at the more physiological air-liquid interface (ALI). The aim of this study was to investigate the cytotoxic and inflammatory potential of CeO2 NPs (NM-212) in a co-culture of A549 lung epithelial cells and differentiated THP-1 cells in both ALI and submerged conditions. Cellular dose was examined quantitatively using inductively coupled plasma mass spectrometry (ICP-MS). The role of serum and LPS-priming for IL-1 beta release was further tested in THP-1 cells in submerged exposure. An aerosol of CeO2 NPs was generated by using the PreciseInhale (R) system, and NPs were deposited on the co-culture using XposeALI (R). No or minor cytotoxicity and no increased release of inflammatory cytokines (IL-1 beta, IL-6, TNF alpha, MCP-1) were observed after exposure of the co-culture in ALI (max 5 mu g/cm(2)) or submerged (max 22 mu g/cm(2)) conditions. In contrast, CeO2 NPs cause clear IL-1 beta release in monocultures of macrophage-like THP-1, independent of the presence of serum and LPS-priming. This study demonstrates a useful approach for comparing effects at various in-vitro conditions.
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3. |
- Cappellini, Francesca, et al.
(författare)
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Mechanistic insight into reactivity and (geno)toxicity of well-characterized nanoparticles of cobalt metal and oxides
- 2018
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Ingår i: Nanotoxicology. - : Taylor & Francis. - 1743-5390 .- 1743-5404. ; 12:6, s. 602-620
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Tidskriftsartikel (refereegranskat)abstract
- An increasing use of cobalt (Co)-based nanoparticles (NPs) in different applications and exposures at occupational settings triggers the need for toxicity assessment. Improved understanding regarding the physiochemical characteristics of Co metal NPs and different oxides in combination with assessment of toxicity and mechanisms may facilitate decisions for grouping during risk assessment. The aim of this study was to gain mechanistic insights in the correlation between NP reactivity and toxicity of three different Co-based NPs (Co, CoO, and Co3O4) by using various tools for characterization, traditional toxicity assays, as well as six reporter cell lines (ToxTracker) for rapid detection of signaling pathways of relevance for carcinogenicity. The results showed cellular uptake of all NPs in lung cells and induction of DNA strand breaks and oxidative damage (comet assay) by Co and CoO NPs. In-depth studies on the ROS generation showed high reactivity of Co, lower for CoO, and no reactivity of Co3O4 NPs. The reactivity depended on the corrosion and transformation/dissolution properties of the particles and the media highlighting the role of the surface oxide and metal speciation as also confirmed by in silico modeling. By using ToxTracker, Co NPs were shown to be highly cytotoxic and induced reporters related to oxidative stress (Nrf2 signaling) and DNA strand breaks. Similar effects were observed for CoO NPs but at higher concentrations, whereas the Co3O4 NPs were inactive at all concentrations tested. In conclusion, our study suggests that Co and CoO NPs, but not Co3O4, may be grouped together for risk assessment.
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4. |
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5. |
- Cronholm, Pontus, et al.
(författare)
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Intracellular Uptake and Toxicity of Ag and CuO Nanoparticles : A Comparison Between Nanoparticles and their Corresponding Metal Ions
- 2013
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Ingår i: Small. - : Wiley. - 1613-6810 .- 1613-6829. ; 9:7, s. 970-982
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Tidskriftsartikel (refereegranskat)abstract
- An increased understanding of nanoparticle toxicity and its impact on human health is essential to enable a safe use of nanoparticles in our society. The aim of this study is to investigate the role of a Trojan horse type mechanism for the toxicity of Ag-nano and CuO-nano particles and their corresponding metal ionic species (using CuCl2 and AgNO3), i.e., the importance of the solid particle to mediate cellular uptake and subsequent release of toxic species inside the cell. The human lung cell lines A549 and BEAS-2B are used and cell death/membrane integrity and DNA damage are investigated by means of trypan blue staining and the comet assay, respectively. Chemical analysis of the cellular dose of copper and silver is performed using atomic absorption spectroscopy. Furthermore, transmission electron microscopy, laser scanning confocal microscopy, and confocal Raman microscopy are employed to study cellular uptake and particle-cell interactions. The results confirm a high uptake of CuO-nano and Ag-nano compared to no, or low, uptake of the soluble salts. CuO-nano induces both cell death and DNA damage whereas CuCl2 induces no toxicity. The opposite is observed for silver, where Ag-nano does not cause any toxicity, whereas AgNO3 induces a high level of cell death. In conclusion: CuO-nano toxicity is predominantly mediated by intracellular uptake and subsequent release of copper ions, whereas no toxicity is observed for Ag-nano due to low release of silver ions within short time periods.
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6. |
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7. |
- Edner, H, et al.
(författare)
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Fluorescence Lidar Multicolor Imaging of Vegetation
- 1994
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Ingår i: Optical Society of America. Journal B: Optical Physics. - 0740-3224. ; 33:13, s. 2471-2479
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Tidskriftsartikel (refereegranskat)abstract
- Multicolor imaging of vegetation fluorescence following laser excitation is reported for distances of 50 m. A mobile laser-radar system equipped with a Nd:YAG laser transmitter and a 40-cm-diameter telescope was utilized. The laser light was Raman shifted to 397 nm with pulse energies of approximately 30 mJ. An image-intensified CCD camera with a specially designed split-mirror Cassegrainian telescope was utilized for the simultaneous recording of fluorescence images of leaves and branches in four different spectral bands. Additionally, fluorescence spectra at selected points within the detection area were measured with an image-intensified diode array system. Image processing permits extraction of information related to the physiological status of the vegetation and might prove useful in forest decline research.
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8. |
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9. |
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10. |
- Ekvall, Mikael T., et al.
(författare)
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Adsorption of bio-organic eco-corona molecules reduces the toxic response to metallic nanoparticles in Daphnia magna
- 2021
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Ingår i: Scientific Reports. - : Springer Nature. - 2045-2322. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- As the use of engineered nanomaterials increases, so does the risk of them spreading to natural ecosystems. Hitherto, knowledge regarding the toxic properties of nanoparticles (NP's) and their potential interactions with natural bio-organic molecules adsorbed to them, and thereby forming surface coronas, is limited. However, we show here that the toxic effect of NPs of tungsten carbide cobalt (WC-Co) and cobalt (Co) on the crustacean Daphnia magna is postponed in the presence of natural biological degradation products (eco-corona biomolecules). For Daphnia exposed to WC-Co NPs the survival time increased with 20-25% and for Co NPs with 30-47% after mixing the particles with a solution of eco-corona biomolecules before exposure. This suggests that an eco-corona, composed of biomolecules always present in natural ecosystems, reduces the toxic potency of both studied NPs. Further, the eco-coronas did not affect the particle uptake, suggesting that the reduction in toxicity was related to the particle-organism interaction after eco-corona formation. In a broader context, this implies that although the increasing use and production of NPs may constitute a novel, global environmental threat, the acute toxicity and long-term effects of some NPs will, at least under certain conditions, be reduced as they enter natural ecosystems.
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11. |
- Ekvall, Mikael T., et al.
(författare)
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Long-term effects of tungsten carbide (WC) nanoparticles in pelagic and benthic aquatic ecosystems
- 2018
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Ingår i: Nanotoxicology. - : Taylor & Francis. - 1743-5390 .- 1743-5404. ; 12:1, s. 79-89
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Tidskriftsartikel (refereegranskat)abstract
- As the production and usage of nanomaterials are increasing so are the concerns related to the release of the material into nature. Tungsten carbide (WC) is widely used for its hard metal properties, although its use, in for instance tyre studs, may result in nano-sized particles ending up in nature. Here, we evaluate the potential long-term exposure effects of WC nanoparticles on a pelagic (Daphnia magna) and a benthic (Asellus aquaticus) organism. No long-term effects were observed in the benthic system with respect to population dynamics or ecosystem services. However, long-term exposure of D. magna resulted in increased time to first reproduction and, if the particles were resuspended, strong effects on survival and reproductive output. Hence, the considerable differences in acute vs. long-term exposure studies revealed here emphasize the need for more long-term studies if we are to understand the effects of nanoparticles in natural systems.
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12. |
- Gupta, G., et al.
(författare)
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Cobalt nanoparticles trigger ferroptosis-like cell death (oxytosis) in neuronal cells : Potential implications for neurodegenerative disease
- 2020
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Ingår i: The FASEB Journal. - : Wiley. - 0892-6638 .- 1530-6860. ; 34:4, s. 5262-5281
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Tidskriftsartikel (refereegranskat)abstract
- The neurotoxicity of hard metal-based nanoparticles (NPs) remains poorly understood. Here, we deployed the human neuroblastoma cell line SH-SY5Y differentiated or not into dopaminergic- and cholinergic-like neurons to study the impact of tungsten carbide (WC) NPs, WC NPs sintered with cobalt (Co), or Co NPs versus soluble CoCl2. Co NPs and Co salt triggered a dose-dependent cytotoxicity with an increase in cytosolic calcium, lipid peroxidation, and depletion of glutathione (GSH). Co NPs and Co salt also suppressed glutathione peroxidase 4 (GPX4) mRNA and protein expression. Co-exposed cells were rescued by N-acetylcysteine (NAC), a precursor of GSH, and partially by liproxstatin-1, an inhibitor of lipid peroxidation. Furthermore, in silico analyses predicted a significant correlation, based on similarities in gene expression profiles, between Co-containing NPs and Parkinson's disease, and changes in the expression of selected genes were validated by RT-PCR. Finally, experiments using primary human dopaminergic neurons demonstrated cytotoxicity and GSH depletion in response to Co NPs and CoCl2 with loss of axonal integrity. Overall, these data point to a marked neurotoxic potential of Co-based but not WC NPs and show that neuronal cell death may occur through a ferroptosis-like mechanism.
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13. |
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14. |
- Hedberg, Jonas, 1979-, et al.
(författare)
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Improving the life cycle impact assessment of metal ecotoxicity : Importance of chromium speciation, water chemistry, and metal release
- 2019
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Ingår i: Sustainability. - : MDPI AG. - 2071-1050. ; 11:6
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Tidskriftsartikel (refereegranskat)abstract
- Investigations of metal ecotoxicity in life cycle assessment (LCA) and life cycle impact assessment (LCIA) are becoming important tools for evaluating the environmental impact of a product or process. There is, however, improvement needed for LCIA of metal ecotoxicity in order to make this assessment more relevant and robust. In this work, three issues within the LCIA of metal ecotoxicity are investigated, mainly focusing on topics related to stainless steel manufacturing. The first issue is the importance of considering regional water chemistry when constructing the characterization factor (CF). A model freshwater of relevance for stainless steel manufacturing in a region of Sweden was created with chemistry different from available options. The second issue is related to the lack of consideration on changes in speciation of Cr(VI) in freshwater for a given emission, as Cr(VI) to some extent will be reduced to Cr(III). Two new options are suggested based on relationships between the Cr(VI)-total Cr ratio as a way to improve the relevancy of LCIA for Cr(VI) in freshwater. The last issue is how to treat metal release from slags in LCIA. Metal release from slags was shown to vary significantly between different ways of modelling slag emissions (differences in total metal content, slag leaching tests, estimated emissions to groundwater). © 2019 by the authors.
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15. |
- Hedberg, Jonas, 1979-, et al.
(författare)
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In the Search for Nanospecific Effects of Dissolution of Metallic Nanoparticles at Freshwater-Like Conditions : A Critical Review
- 2019
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 53:8, s. 4030-4044
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Tidskriftsartikel (refereegranskat)abstract
- Knowledge on relations between particle properties and dissolution/transformation characteristics of metal and metal oxide nanoparticles (NPs) in freshwater is important for risk assessment and product development. This critical review aims to elucidate nanospecific effects on dissolution of metallic NPs in freshwater and similar media. Dissolution rate constants are compiled and analyzed for NPs of silver (Ag), copper (Cu), copper oxide/hydroxide (CuO, Cu(OH) 2 ), zinc oxide (ZnO), manganese (Mn), and aluminum (Al), showing largely varying (orders of magnitude) constants when modeled using first order kinetics. An effect of small primary sizes (<15 nm) was observed, leading to increased dissolution rate constants and solubility in some cases. However, the often extensive particle agglomeration can result in reduced nanospecific effects on dissolution and also an increased uncertainty related to the surface area, a parameter that largely influence the extent of dissolution. Promising ways to model surface areas of NPs in solution using fractal dimensions and size distributions are discussed in addition to nanospecific aspects related to other processes such as corrosion, adsorption of natural organic matter (NOM), presence of capping agents, and existence of surface defects. The importance of the experimental design on the results of dissolution experiments of metal and metal oxide NPs is moreover highlighted, including the influence of ionic metal solubility and choice of particle dispersion methodology.
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16. |
- Hedberg, Jonas, et al.
(författare)
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Interactions between surfactants and silver nanoparticles of varying charge
- 2012
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Ingår i: Journal of Colloid and Interface Science. - Amsterdam : Elsevier. - 0021-9797 .- 1095-7103. ; 369:1, s. 193-201
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Tidskriftsartikel (refereegranskat)abstract
- The interaction between silvernanoparticles (Ag NPs) of different surface charge and surfactants relevant to the laundry cycle has been investigated to understand changes in speciation, both in and during transport from the washing machine. Ag NPs were synthesized to exhibit either a positive or a negative surface charge in solution conditions relevant for the laundry cycle (pH 10 and pH 7). These particles were characterized in terms of size and surface charge and compared to commercially laser ablated Ag NPs. The surfactants included anionic sodium dodecylbenzenesulfonate (LAS), cationic dodecyltrimethylammoniumchloride (DTAC) and nonionic Berol 266 (Berol). Surfactant–Ag NP interactions were studied by means of dynamic light scattering, Raman spectroscopy, zeta potential, and Quartz Crystal Microbalance. Mixed bilayers of CTAB and LAS were formed through a co-operative adsorption process on positively charged Ag NPs with pre-adsorbed CTAB, resulting in charge reversal from positive to negative zeta potentials. Adsorption of DTAC on negatively charged synthesized Ag NPs and negatively charged commercial Ag NPs resulted in bilayer formation and charge reversal. Weak interactions were observed for nonionic Berol with all Ag NPs via hydrophobic interactions, which resulted in decreased zeta potentials for Berol concentrations above its critical micelle concentration. Differences in particle size were essentially not affected by surfactant adsorption, as the surfactant layer thicknesses did not exceed more than a few nanometers. The surfactant interaction with the Ag NP surface was shown to be reversible, an observation of particular importance for hazard and environmental risk assessments.
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17. |
- Hedberg, Jonas, et al.
(författare)
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Ion selective electrodes are not suitable for measurements of silver ion concentrations in alkaline carbonate media
- 2013
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Ingår i: Analytical Methods. - : RSC Publishing. - 1759-9660 .- 1759-9679. ; 5:4, s. 1068-1070
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Tidskriftsartikel (refereegranskat)abstract
- An ion selective electrode (ISE) for determination of the labile silver ion concentration in carbonate containing solutions of pH 10 was seen to give incorrect results due to shifts in the Ag vertical bar Ag+ equilibrium. This drawback was not the case for the differential pulse anodic stripping voltammetry (DPASV) method.
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18. |
- Hedberg, Jonas, et al.
(författare)
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Sequential Studies of Silver Released from Silver Nanoparticles in Aqueous Media Simulating Sweat, Laundry Detergent Solutions and Surface Water
- 2014
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 48:13, s. 7314-7322
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Tidskriftsartikel (refereegranskat)abstract
- From an increased use of silver nanoparticles (Ag NPs) as an antibacterial in consumer products follows a need to assess the environmental interaction and fate of their possible dispersion and release of silver. This study aims to elucidate an exposure scenario of the Ag NPs potentially released from, for example, impregnated clothing by assessing the release of silver and changes in particle properties in sequential contact with synthetic sweat, laundry detergent solutions, and freshwater, simulating a possible transport path through different aquatic media. The release of ionic silver is addressed from a water chemical perspective, compared with important particle and surface characteristics. Released amounts of silver in the sequential exposures were significantly lower, approximately a factor of 2, than the sum of each separate exposure. Particle characteristics such as speciation (both of Ag ionic species and at the Ag NP surface) influenced the release of soluble silver species present on the surface, thereby increasing the total silver release in the separate exposures compared with sequential immersions. The particle stability had no drastic impact on the silver release as most of the Ag NPs were unstable in solution. The silver release was also influenced by a lower pH (increased release of silver), and cotransported zeolites (reduced silver in solution).
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19. |
- Hedberg, Jonas, et al.
(författare)
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Sorption and dissolution of bare and coated silver nanoparticles in soil suspensions-Influence of soil and particle characteristics
- 2015
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Ingår i: Journal of Environmental Science and Health. Part A. - 1093-4529 .- 1532-4117. ; 50:9, s. 891-900
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Tidskriftsartikel (refereegranskat)abstract
- The increasing use of silver nanoparticles (AgNPs) in consumer products triggers the need for investigations that improve the understanding of their chemical transformations upon environmental entry. Such knowledge provides crucial information for toxicological studies and risk assessments. Interactions with the soil compartment need to be explored as there are evident risks of the dispersion of both AgNPs and of released Ag ions/complexes present in wastewater-treated sludge that is distributed onto agricultural land. The dissolution and fractionation in solution of bare (AgNP-bare, noncoated) and coated AgNPs (AgNP-coat, stabilized with two nonionic surfactants, polyoxyethylene glycerol trioleate and Tween 20) were investigated after 4 and 48h in suspensions of one sandy and one clayey soil of different pHs (3.3, 5.2). Parallel experiments were performed with soil suspensions spiked with easily soluble AgNO3. Silver in the water phase was separated in a dissolved fraction (mainly Ag ions/complexes) and a particle fraction (mainly AgNP/agglomerates/Ag adsorbed on organic matter) by means of ultracentrifugation. Bare AgNPs were nonstable and dissolved to a significantly larger extent in the sandy soil mixture compared to coated AgNPs. The concentration of dissolved Ag (ions/complexes) in the water phase was similar in the case of bare AgNPs and AgNO3 (at pH 3 and 5.2) after 24h in sandy soil, which implies a high degree of dissolution of bare AgNPs (50-100%). In contrast, approximately 50% of the coated AgNPs remained in the water phase after 48h of equilibration in the sandy soil at pH 5.2. The clayey soil had a significantly higher sorption capacity of Ag compared with the sandy soil, as Ag in the case of coated AgNPs was only detected in the water phase of pH 5.2 (<1 % of added Ag). Ultracentrifugation was proven more efficient compared with microfiltration to separate the dissolved Ag fraction (ions/complexes) and the particle fraction (AgNPs/agglomerates) of the water phase. This fractionation is not a measure of any potential toxicity.
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20. |
- Hedberg, Jonas, et al.
(författare)
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Spatial distribution and formation of corrosion products in relation to zinc release for zinc sheet and coated pre-weathered zinc at an urban and a marine atmospheric condition
- 2013
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Ingår i: Materials and corrosion - Werkstoffe und Korrosion. - : Wiley. - 0947-5117 .- 1521-4176. ; 64:4, s. 300-308
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Tidskriftsartikel (refereegranskat)abstract
- Zinc release data from 5 years of unsheltered exposures in a marine and an urban site is compiled for different zinc material types. The thin surface treatment on zinc materials is gradually detached after approximately 2 years at both sites, revealing the pre-weathered zinc surface unprotected. This consequently increased the release rates of zinc from this surface, whereas the zinc runoff rate from the bare zinc sheet remained relatively stable. Raman studies on bare zinc sheet exposed for 5 years at the marine site revealed zinc oxide of varying crystalline nature and hydrozincite to appear localized and separated from each other.
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21. |
- Hedberg, Jonas, et al.
(författare)
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The importance of extracellular speciation and corrosion of copper nanoparticles on lung cell membrane integrity
- 2016
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Ingår i: Colloids and Surfaces B. - : Elsevier. - 0927-7765 .- 1873-4367. ; 141, s. 291-300
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Tidskriftsartikel (refereegranskat)abstract
- Copper nanoparticles (Cu NPs) are increasingly used in various biologically relevant applications and products, e.g., due to their antimicrobial and catalytic properties. This inevitably demands for an improved understanding on their interactions and potential toxic effects on humans. The aim of this study was to investigate the corrosion of copper nanoparticles in various biological media and to elucidate the speciation of released copper in solution. Furthermore, reactive oxygen species (ROS) generation and lung cell (A549 type II) membrane damage induced by Cu NPs in the various media were studied. The used biological media of different complexity are of relevance for nanotoxicological studies: Dulbecco's modified eagle medium (DMEM), DMEM+ (includes fetal bovine serum), phosphate buffered saline (PBS), and PBS + histidine. The results show that both copper release and corrosion are enhanced in DMEM+, DMEM, and PBS + histidine compared with PBS alone. Speciation results show that essentially no free copper ions are present in the released fraction of Cu NPs in neither DMEM+, DMEM nor histidine, while labile Cu complexes form in PBS. The Cu NPs were substantially more membrane reactive in PBS compared to the other media and the NPs caused larger effects compared to the same mass of Cu ions. Similarly, the Cu NPs caused much more ROS generation compared to the released fraction only. Taken together, the results suggest that membrane damage and ROS formation are stronger induced by Cu NPs and by free or labile Cu ions/complexes compared with Cu bound to biomolecules.
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22. |
- Hedberg, Jonas, 1979-, et al.
(författare)
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Transformation of silver nanoparticles released from skin cream and mouth spray in artificial sweat and saliva solutions : particle size, dissolution, and surface area
- 2020
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Ingår i: Environmental Science and Pollution Research. - : Springer Science and Business Media Deutschland GmbH. - 0944-1344 .- 1614-7499.
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Tidskriftsartikel (refereegranskat)abstract
- The use of silver nanoparticles (Ag NPs) in consumer products can result in diffuse environmental dispersion of both NPs and ionic silver. This study investigated the transformation of Ag NPs present in two consumer products (skin cream, mouth spray) in terms of release of Ag NPs and ionic silver and changes in particle size in artificial sweat and saliva solutions. Large differences in silver release were observed with the smaller sized Ag NPs in mouth spray releasing more silver compared with the Ag NPs of the skin cream. Substantial particle agglomeration took place in both artificial sweat and saliva, forming large-sized agglomerates (> 100 nm). The amount of dissolved silver in solution after 24 h was less than 10% of the total amount of Ag NPs for both products. The results show that the Ag NPs of these consumer products will largely remain as NPs even after 24 h of skin or saliva contact. The use of normalization by geometric surface area of the particles was tested as a way to compare dissolution for Ag NPs of different characteristics, including pristine, bare, as well as PVP-capped Ag NPs. Normalization of silver dissolution with the geometric surface area was shown promising, but more extensive studies are required to unambiguously conclude whether it is a way forward to enable grouping of the dissolution behavior of Ag NPs released from consumer products.
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23. |
- Hedberg, Jonas, et al.
(författare)
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Transport and fate of silver as polymer-stabilised nanoparticles and ions in a pilot wastewater treatment plant, followed by sludge digestion and disposal of sludge/soil mixtures : A case study
- 2014
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Ingår i: Journal of Environmental Science and Health. Part A. - : Informa UK Limited. - 1093-4529 .- 1532-4117. ; 49:12, s. 1416-1424
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Tidskriftsartikel (refereegranskat)abstract
- A case study of transport and changes in properties of polymer-stabilised Ag NPs is presented in this paper investigating their interaction in different treatment steps within a fully realistic pilot wastewater treatment plant (WWTP), in anaerobic digested sludge, and in soil/sludge mixtures. The fate of the same Ag NPs was tracked in these environments, hence taking the history of the Ag NPs into account. The results show that most of the Ag NPs end up in the sludge (80-100%), also after anaerobically digestion. Furthermore, the fraction of silver in the supernatant was very low after 48h incubation with silver-containing digested sludge mixed with different soil types. However, when Ag NPs were added directly to the sludge/soil mixture, soluble silver was present in the supernatant with sandy soil, but not with clayey soil. In all, generated findings show that risk assessments and toxicological studies of Ag NPs suspensions must take into account possible chemical and particle transformations upon environmental entry, as silver in general become less soluble when transported to WWTPs and interacting with sludge, and soil.
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24. |
- Hedberg, Jonas, 1979-, et al.
(författare)
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Tungsten carbide nanoparticles in simulated surface water with natural organic matter : dissolution, agglomeration, sedimentation and interaction with Daphnia magna
- 2017
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Ingår i: Environmental Science: Nano. - : Royal Society of Chemistry. - 2051-8153 .- 2051-8161. ; 4:4, s. 886-894
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Tidskriftsartikel (refereegranskat)abstract
- Even though anthropogenic nano-sized tungsten carbide nanoparticles (WC NPs) have been found in the environment, there are currently no investigations on their environmental fate. This work studies the interaction between natural organic matter (NOM) and WC NPs, as well as the potential uptake by the aquatic model organism Daphnia magna. We here show that the affinity between WC NPs and humic acid or dihydroxybenzoic acid (DHBA), which are model molecules of NOM, is very low with no observed surface adsorption. The lack of a stabilizing effect of these organic molecules, in combination with a relatively high effective density of WC NP agglomerates in humic acid, resulted in the substantial agglomeration and sedimentation of the WC NPs. A higher stability of the smaller sized WC NP agglomerates (<150 nm) means that this fraction is mobile and can be transported to other settings, suggesting that this particle fraction should be considered in further studies. The dissolution of tungsten from WC NPs was continuous and the relatively slow dissolution rate (on the order of 0.03 mg m-2 h-1) implies that particle transport will not be severely limited from a dissolution perspective. Uptake of tungsten (dissolved tungsten and WC particles) by D. magna was observed although this did not induce any acute toxic effects.
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25. |
- Hedberg, Jonas, et al.
(författare)
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Utvärdering och optimering av filtreringstekniker i reningsverk för att separera skadliga nanopartiklar
- 2013
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Silvernanopartiklar används i en ökande utsträckning, främst på grund av deras anti-bakteriella egenskaper, vilket utnyttjas i produkter som kläder och beläggningar för att till exempel motverka svettlukt. Framtida scenarier för emissioner av silvernanopartiklar har pekat på risker för vattenlevande organismer efter det att silverpartiklarna släppts ut i avloppsvatten och passerat genom vattenreningsverk och därefter spridits till vattenrecipienter. Därför är det viktigt att förstå hur partiklarnas egenskaper förändras i en kommunal vattenreningsprocess och hur dessa partiklar binds till organiskt material och andra partiklar i avloppsvattnet. Detta ger information huruvida silvernanopartiklarna hamnar i slammet eller i det utgående vattnet samt i vilken omfattning. Denna kunskap kan sedan användas för att kunna uppskatta risker med eventuella ökade halter silvernanopartiklar i dessa strömmar. En annan viktig aspekt är design av filtreringstekniker för nanopartiklar. I detta projekt behandlas dessa frågeställningar genom experiment i ett pilotvatten-reningsverk som är en kopia av ett standardiserat kommunalt avloppsvattenreningsverk (ARV). Det nya i denna studie är att undersökningarna genomförts under helt realistiska förhållanden i en komplett vattenreningsprocess, vilken inkluderar samtliga reningssteg. Dessutom följs växelverkan av silverpartiklar/silverkomplex genom alla steg i reningen, även i den efterföljande rötningen. Resultaten i denna rapport visar att silver i form av avsiktligt tillsatta nanopartiklar i det inkommande spillvattnet till reningsverket (Stockholm innerstads avloppsvatten) till en betydande del (80-100 procent) hamnar i slammet vid en vattenreningsprocess. Silvernanopartiklarnas beteende är likartat med silverjoner i detta avseende. Mikroskopimätningar visar att det är rimligt att anta att silvernanopartiklarna till viss del fastnar på material i slammet. Liknande resultat erhölls för både tillsatta silvernanopartiklar och tillsatta silverjoner, med den lilla skillnaden att silverjonerna sedimenterade något snabbare än silvernanopartiklarna. Vid rötning av slam innehållande silvernanopartiklar/silverjoner, följt av centrifugering för avvattning, visar det sig att majoriteten av silvret (>95 procent) fortfarande är bundet till slammet. Efter att silvernanopartiklar passerat vattenreningsverket uppför de sig alltså inte som singulära nanopartiklar dispergerade i lösning. De adsorberas till slammet där de troligtvis löses upp till stor del och transformeras till silversulfid. Resultaten visar att fokus bör ligga på spridningen av silver i slam och de kemiska förekomstformerna för vidare studier av de risker som en ökad användning av silver i konsumentprodukter, medför.
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26. |
- Hedberg, Yolanda, et al.
(författare)
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Complexation- and ligand-induced metal release from 316L particles : importance of particle size and crystallographic structure
- 2011
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Ingår i: Biometals. - : Springer Science and Business Media LLC. - 0966-0844 .- 1572-8773. ; 24:6, s. 1099-1114
-
Tidskriftsartikel (refereegranskat)abstract
- Iron, chromium, nickel, and manganese released from gas-atomized AISI 316L stainless steel powders (sized < 45 and < 4 mu m) were investigated in artificial lysosomal fluid (ALF, pH 4.5) and in solutions of its individual inorganic and organic components to determine its most aggressive component, elucidate synergistic effects, and assess release mechanisms, in dependence of surface changes using atomic absorption spectroscopy, Raman, XPS, and voltammetry. Complexation is the main reason for metal release from 316L particles immersed in ALF. Iron was mainly released, while manganese was preferentially released as a consequence of the reduction of manganese oxide on the surface. These processes resulted in highly complexing media in a partial oxidation of trivalent chromium to hexavalent chromium on the surface. The extent of metal release was partially controlled by surface properties (e.g., availability of elements on the surface and structure of the outermost surface) and partially by the complexation capacity of the different metals with the complexing agents of the different media. In general, compared to the coarse powder (< 45 mu m), the fine (< 4 mu m) powder displayed significantly higher released amounts of metals per surface area, increased with increased solution complexation capacity, while less amounts of metals were released into non-complexing solutions. Due to the ferritic structure of lower solubility for nickel of the fine powder, more nickel was released into all solutions compared with the coarser powder.
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27. |
- Hedberg, Yolanda, et al.
(författare)
-
Correlation between surface physicochemical properties and the release of iron from stainless steel AISI 304 in biological media
- 2014
-
Ingår i: Colloids and Surfaces B. - : Elsevier BV. - 0927-7765 .- 1873-4367. ; 122, s. 216-222
-
Tidskriftsartikel (refereegranskat)abstract
- Stainless steel is widely used in biological environments, for example as implant material or in food applications, where adsorption-controlled ligand-induced metal release is of importance from a corrosion, health, and food safety perspective. The objective of this study was to elucidate potential correlations between surface energy and wettability of stainless steel surfaces and the release of iron in complexing biological media. This was accomplished by studying changes in surface energies calculated from contact angle measurements, surface oxide composition (X-ray photoelectron spectroscopy), and released iron (graphite furnace atomic absorption spectroscopy) for stainless steel grade AISI 304 immersed in fluids containing bovine serum albumin or citric acid, and non-complexing fluids such as NaCl, NaOH, and HNO3. It was shown that the surface wettability and polar surface energy components were all influenced by adventitious atmospheric carbon (surface contamination of low molecular weight), rather than differences in surface oxide composition in non-complexing solutions. Adsorption of both BSA and citrate, which resulted in ligand-induced metal release, strongly influenced the wettability and the surface energy, and correlated well with the measured released amount of iron.
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28. |
- Hedberg, Yolanda, 1985-, et al.
(författare)
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Interaction of Albumin and Fibrinogen with Stainless Steel : Influence of Sequential Exposure and Protein Aggregation on Metal Release and Corrosion Resistance
- 2017
-
Ingår i: Corrosion. - : NATL ASSOC CORROSION ENG. - 0010-9312 .- 1938-159X. ; 73:12
-
Tidskriftsartikel (refereegranskat)abstract
- Corrosion and metal release mechanisms of the biomedical stainless steel grade Type 316L are at human-relevant biological conditions not fully understood. This study focuses on its corrosion properties and release of iron (Fe), chromium (Cr), manganese (Mn), and nickel (Ni) into simulated physiological solutions at pH 7.4 in the presence of proteins. Parallel studies were performed on stainless steel Type 303 containing a substantial amount of MnS inclusions. Metal release studies were performed in phosphate buffered saline (PBS) for 4 h and 24 h at 37 degrees C with or without different concentrations of bovine serum albumin (BSA), fibrinogen from bovine plasma (Fbn), or mixtures of the same. Studies were in addition performed after 1, 4, 6, and 24 h in solutions that were partially replenished after 5 h in order to investigate whether any Vroman effect (exchange of adsorbed proteins by proteins of higher binding affinity) could influence the extent of released metals in solution. This was performed at physiological concentrations of BSA (40 g/L) and Fbn (2.67 g/L) in PBS, and for reference solutions of PBS, PBS with 40 g/L BSA, and PBS with 2.67 g/L Fbn. Changes in open-circuit potential and linear polarization resistance were investigated for the same conditions. After exposure, the exposed surfaces were rinsed and investigated ex situ by means of x-ray photoelectron spectroscopy and infrared reflection absorption spectroscopy. Metal-protein complexation-induced metal release mechanisms were found to be most pronounced for Type 316L and the release of Fe, Cr, and Ni. Fibrinogen adsorbed differently onto Type 303 (thicker conformation of adsorbed proteins) as compared with Type 316L and occasionally induced corrosion events for Type 303. Mn was mostly released from inclusions present in the Type 303 alloy, most probably via non-electrochemical mechanisms. A Vroman effect was observed for both grades. A significant extent of precipitation of metal-rich protein aggregates influenced the metal release measurements in solution and resulted in an underestimation of the total amount of released metals from the stainless steel grades.
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29. |
- Hedberg, Yolanda, 1985-, et al.
(författare)
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Nanoparticles of WC-Co, WC, Co and Cu of relevance for traffic wear particles – Particle stability and reactivity in synthetic surface water and influence of humic matter
- 2017
-
Ingår i: Environmental Pollution. - : Elsevier. - 0269-7491 .- 1873-6424. ; 224, s. 275-288
-
Tidskriftsartikel (refereegranskat)abstract
- Studded tyres made of tungsten carbide cobalt (WC-Co) are in the Northern countries commonly used during the winter time. Tungsten (W)-containing nano- and micron-sized particles have been detected close to busy roads in several European countries. Other typical traffic wear particles consist of copper (Cu). The aims of this study were to investigate particle stability and transformation/dissolution properties of nanoparticles (NPs) of WC-Co compared with NPs of tungsten carbide (WC), cobalt (Co), and Cu. Their physicochemical characteristics (primarily surface oxide and charge) are compared with their extent of sedimentation and metal release in synthetic surface water (SW) with and without two different model organic molecules, 2,3- and 3,4-dihydroxybenzoic acid (DHBA) mimicking certain sorption sites of humic substances, for time periods up to 22 days. The WC-Co NPs possessed a higher electrochemical and chemical reactivity in SW with and without DHBA molecules as compared with NPs of WC, Co, and Cu. Co was completely released from the WC-Co NPs within a few hours of exposure, although it remained adsorbed/bonded to the particle surface and enabled the adsorption of negatively charged DHBA molecules, in contrast with the WC NPs (no adsorption of DHBA). The DHBA molecules were found to rapidly adsorb on the Co and Cu NPs. The sedimentation of the WC and WC-Co NPs was not influenced by the presence of the 2,3- or 3,4-DHBA molecules. A slight influence (slower sedimentation) was observed for the Co NPs, and a strong influence (slower sedimentation) was observed for the Cu NPs in SW with 2,3-DHBA compared with SW alone. The extent of metal release increased in the order: WC < Cu < Co < WC-Co NPs. All NPs released more than 1 wt-% of their metal total mass. The release from the Cu NPs was most influenced by the presence of DHBA molecules.
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30. |
- Hedberg, Yolanda, et al.
(författare)
-
Particle characteristics and metal release from natural rutile (TiO2) and zircon particles in synthetic body fluids
- 2012
-
Ingår i: Journal of Biomaterials and Nanobiotechnology. - : Scientific Research Publishing, Inc.. - 2158-7027 .- 2158-7043. ; 3:1, s. 37-49
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Tidskriftsartikel (refereegranskat)abstract
- Titanium oxide (rutile, TiO2) and zircon (ZrSiO4), known insoluble ceramic materials, are commonly used for coatings of implant materials. We investigate the release of zirconium, titanium, aluminum, iron, and silicon from different micron-sized powders of 6 powders of natural rutile (TiO2) and zircon (ZrSiO4) from a surface perspective. The investiga- tion includes five different synthetic body fluids and two time periods of exposure, 2 and 24 hours. The solution chemi- cals rather than pH are important for the release of zirconium. When exceeding a critical amount of aluminum and sili- con in the surface oxide, the particles seem to be protected from selective pH-specific release at neutral or weakly alka- line pH. The importance of bulk and surface composition and individual changes between different kinds of the same material is elucidated. Changes in material properties and metal release characteristics with particle size are presented for zircon.
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31. |
- Hedberg, Yolanda S., et al.
(författare)
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Critical Review : Copper Runoff from Outdoor Copper Surfaces at Atmospheric Conditions
- 2014
-
Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 48:3, s. 1372-1381
-
Forskningsöversikt (refereegranskat)abstract
- This review on copper runoff dispersed from unsheltered naturally patinated copper used for roofing and facades summarizes and discusses influencing factors, available literature, and predictive models, and the importance of fate and speciation for environmental risk assessment. Copper runoff from. outdoor surfaces is predominantly governed by electrochemical and chemical reactions and is highly dependent on given exposure conditions (size, inclination, geometry, degree of sheltering, and orientation), surface parameters (age, patina composition, and thickness), and site-specific environmental conditions (gaseous pollutants, chloride, rainfall characteristics (amount, intensity, pH), wind direction, temperature, time of wetness, season). The corrosion rate cannot be used to assess the runoff rate. The extent of released copper varies largely between different rain events and is related to dry and wet periods, dry deposition prior to the rain event and prevailing rain and patina characteristics. Interpretation and use of copper runoff data for environmental risk assessment and management need therefore to consider site-specific factors and focus on average data of long-term studies (several years). Risk assessments require furthermore that changes in copper speciation, bioavailability aspects, and potential irreversible retention on solid surfaces are considered, factors that determine the environmental fate of copper runoff from outdoor surfaces.
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32. |
- Hedberg, Yolanda S., et al.
(författare)
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Electrochemical surface oxide characteristics of metal nanoparticles (Mn, Cu and Al) and the relation to toxicity
- 2016
-
Ingår i: Electrochimica Acta. - : Elsevier BV. - 0013-4686 .- 1873-3859. ; 212, s. 360-371
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Tidskriftsartikel (refereegranskat)abstract
- Most metal nanoparticles (NPs), except noble metal NPs, rapidly form a thin surface oxide in ambient conditions. The protective properties of these oxides improve or worsen depending on the environment, e.g., the human lung. Several properties, including the chemical/electrochemical stability and defect density, determine the capacity of these surface oxides to hinder the bulk metal from further oxidation (corrosion). The aim of this study was to investigate whether electrochemical surface oxide characterization of non-functionalized base metal NPs of different characteristics (Al, Mn and Cu) can assist in understanding their bioaccessibility (metal release) in cell media (DMEM+) and their cytotoxic properties following exposure in lung epithelial (A549) cells. The composition and valence states of surface oxides of metal NPs and their electrochemical activity were investigated using an electrochemical technique based on a graphite paste electrode to perform cyclic voltammetry in buffer solutions and open circuit potential measurements in DMEM+. The electrochemical surface oxide characterization was complemented and verified by Raman spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The open circuit potential trends in DMEM+ correlated well with metal release results in the same solution, and provided information on the kinetics of oxide dissolution in the case of Cu NPs. Extensive particle agglomeration in cell medium (DMEM+) was observed by means of photon-cross correlation spectroscopy for all metal NPs, with sedimentation taking place very quickly. As a consequence, measurements of the real dose of added non-functionalized metal NPs to cell cultures for cytotoxicity testing from a sonicated stock solution were shown necessary. The cytotoxic response was found to be strongly correlated to changes in physico-chemical and electrochemical properties of the surface oxides of the metal NPs, the most potent being Cu NPs, followed by Mn NPs. No cytotoxicity was observed for Al NPs. The electrochemical surface oxide characterization corresponded well with other tools commonly used for nanotoxicological characterization and provided additional information.
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33. |
- Hedberg, Yolanda, et al.
(författare)
-
Surface characterisation of fine inert gas and water atomised stainless steel 316L powders: formation of thermodynamically unstable surface oxide phases
- 2013
-
Ingår i: Powder Metallurgy. - 0032-5899 .- 1743-2901. ; 56:2, s. 158-163
-
Tidskriftsartikel (refereegranskat)abstract
- New insights are presented on the speciation of surface oxide phases on fine inert gas atomised(GA, ,45 and ,4 mm) and water atomised (WA, ,45 mm) stainless steel AISI 316L powders. Xrayphotoelectron and Auger electron spectroscopy, scanning electron microscopy, Ramanspectroscopy, and cyclic voltammetry were applied for the characterisation. Oxidisedmanganese was strongly enriched in the outermost surface oxide of the GA powders (13 and47 wt-%), an effect increasing with reduced particle size. Manganese and sulphur were enrichedin oxide nanoparticles on the surface. Oxidised silicon (59 wt-%) was enriched on the WA powdersurface. Tri- or tetravalent manganese oxides were observed on the GA particles in addition to a-Fe2O3, and Cr2O3. The oxide of the WA powder revealed in addition the likely presence of asilicate rich phase, mainly consisting of tetravalent Si, di- and/or trivalent Fe, and hexavalent Cr,which was confirmed not present as chromate.
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34. |
- Hedberg, Yolanda, et al.
(författare)
-
Surface-protein interactions on different stainless steel grades : effects of protein adsorption, surface changes and metal release
- 2013
-
Ingår i: Journal of materials science. Materials in medicine. - : Springer Science and Business Media LLC. - 0957-4530 .- 1573-4838. ; 24:4, s. 1015-1033
-
Tidskriftsartikel (refereegranskat)abstract
- Implantation using stainless steels (SS) is an example where an understanding of protein-induced metal release from SS is important when assessing potential toxicological risks. Here, the protein-induced metal release was investigated for austenitic (AISI 304, 310, and 316L), ferritic (AISI 430), and duplex (AISI 2205) grades in a phosphate buffered saline (PBS, pH 7.4) solution containing either bovine serum albumin (BSA) or lysozyme (LSZ). The results show that both BSA and LSZ induce a significant enrichment of chromium in the surface oxide of all stainless steel grades. Both proteins induced an enhanced extent of released iron, chromium, nickel and manganese, very significant in the case of BSA (up to 40-fold increase), whereas both proteins reduced the corrosion resistance of SS, with the reverse situation for iron metal (reduced corrosion rates and reduced metal release in the presence of proteins). A full monolayer coverage is necessary to induce the effects observed.
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35. |
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36. |
- Holm, Alexander, et al.
(författare)
-
Patients' perspective on prostatic artery embolization : A qualitative study
- 2021
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Ingår i: SAGE Open Medicine. - : SAGE Open. - 2050-3121. ; 9, s. 1-6
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: The aim was to describe the patients' experience of undergoing prostatic artery embolization.Methods: A retrospective qualitative interview study was undertaken with 15 patients of mean age 73 years who had undergone prostatic artery embolization with a median duration of 210 min at two medium sized hospitals in Sweden. The reasons for conducting prostatic artery embolization were clean intermittent catheterization (n = 4), lower urinary tract symptoms (n = 10) or haematuria (n = 1). Data were collected through individual, semi-structured telephone interviews 1-12 months after treatment and analysed using qualitative content analysis.Results: Four categories with sub-categories were formulated to describe the results: a diverse experience; ability to control the situation; resumption of everyday activities and range of opinions regarding efficacy of outcomes. Overall, the patients described the procedure as painless, easy and interesting and reported that while the procedure can be stressful, a calm atmosphere contributed to achieving a good experience. Limitations on access to reliable information before, during and after the procedure were highlighted as a major issue. Practical ideas for improving patient comfort during the procedure were suggested. Improved communications between treatment staff and patients were also highlighted. Most patients could resume everyday activities, some felt tired and bruising caused unnecessary worry for a few. Regarding functional outcome, some patients described substantial improvement in urine flow while others were satisfied with regaining undisturbed night sleep. Those with less effect were considering transurethral resection of the prostate as a future option. Self-enrolment to the treatment and long median operation time may have influenced the results.Conclusions: From the patients' perspective, prostatic artery embolization is a well-tolerated method for treating benign prostate hyperplacia.
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37. |
- Kessler, Amanda, et al.
(författare)
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Adsorption of Horseradish Peroxidase on Metallic Nanoparticles : Effects on Reactive Oxygen Species Detection Using 2′,7′-Dichlorofluorescin Diacetate
- 2021
-
Ingår i: Chemical Research in Toxicology. - : American Chemical Society. - 0893-228X .- 1520-5010. ; 350, s. S215-S216
-
Tidskriftsartikel (refereegranskat)abstract
- The fluorescent probe 2′,7′-dichlorofluorescein diacetate (DCFH-DA) together with the enzyme horseradish peroxidase (HRP) is widely used in nanotoxicology to study acellular reactive oxygen species (ROS) production from nanoparticles (NPs). This study examined whether HRP adsorbs onto NPs of Mn, Ni, and Cu and if this surface process influences the extent of metal release and hence the ROS production measurements using the DCFH assay in phosphate buffered saline (PBS), saline, or Dulbecco's modified Eagle's medium (DMEM). Adsorption of HRP was evident onto all NPs and conditions, except for Mn NPs in PBS. The presence of HRP resulted in an increased release of copper from the Cu NPs in PBS and reduced levels of nickel from the Ni NPs in saline. Both metal ions in solution and the adsorption of HRP onto the NPs can change the activity of HRP and thus influence the ROS results. The effect of HRP on the NP reactivity was shown to be solution chemistry dependent. Most notable was the evident affinity/adsorption of phosphate toward the metal NPs, followed by a reduced adsorption of HRP, the concomitant reduction in released manganese from the Mn NPs, and increased levels of released metals from the Cu NPs in PBS. Minor effects were observed for the Ni NPs. The solution pH should be monitored since the release of metals can change the solution pH and the activity of HRP is known to be pH-dependent. It is furthermore essential that solution pH adjustments are made following the addition of NaOH during diacetyl removal of DCFH-DA. Even though not observed for the given exposure conditions of this study, released metal ions could possibly induce agglomeration or partial denaturation of HRP, which in turn could result in steric hindrance for H2O2 to reach the active site of HRP. This study further emphasizes the influence of HRP on the background kinetics, its solution dependence, and effects on measured ROS signals. Different ways of correcting for the background are highlighted, as this can result in different interpretations of generated results. The results show that adsorption of HRP onto the metal NPs influenced the extent of metal release and may, depending on the investigated system, result in either under- or overestimated ROS signals if used together with the DCFH assay. HRP should hence be used with caution when measuring ROS in the presence of reactive metallic NPs. © 2021 The Authors.
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38. |
- Khort, Alexander, et al.
(författare)
-
Corrosion and transformation of solution combustion synthesized Co, Ni and CoNi nanoparticles in synthetic freshwater with and without natural organic matter
- 2021
-
Ingår i: Scientific Reports. - : Nature Research. - 2045-2322. ; 11:1
-
Tidskriftsartikel (refereegranskat)abstract
- Pure metallic Co, Ni, and their bimetallic compositions of Co3Ni, CoNi, and CoNi3 nanomaterials were prepared by solution combustion synthesis. Microstructure, phase composition, and crystalline structure of these nanoparticles (NPs) were characterized along with studies of their corrosion and dissolution properties in synthetic freshwater with and without natural organic matter (NOM). The nanomaterials consisted of aggregates of fine NPs (3–30 nm) of almost pure metallic and bimetallic crystal phases with a thin surface oxide covered by a thin carbon shell. The nanomaterials were characterized by BET surface areas ranging from ~ 1 to 8 m2/g for the Ni and Co NPs, to 22.93 m2/g, 14.86 m2/g, and 10.53 m2/g for the Co3Ni, CoNi, CoNi3 NPs, respectively. More Co and Ni were released from the bimetallic NPs compared with the pure metals although their corrosion current densities were lower. In contrast to findings for the pure metal NPs, the presence of NOM increased the release of Co and Ni from the bimetallic NPs in freshwater compared to freshwater only even though its presence reduced the corrosion rate (current density). It was shown that the properties of the bimetallic nanomaterials were influenced by multiple factors such as their composition, including carbon shell, type of surface oxides, and the entropy of mixing. © 2021, The Author(s).
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39. |
- Khort, Aliaksandr, Dr, 1987-, et al.
(författare)
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Influence of natural organic matter on the transformation of metal and metal oxide nanoparticles and their ecotoxic potency in vitro
- 2022
-
Ingår i: Nanoimpact. - : Elsevier BV. - 2452-0748. ; 25
-
Tidskriftsartikel (refereegranskat)abstract
- Increased use and production of engineered nanoparticles (NPs) lead to an elevated risk of their diffuse dispersion into the aquatic environment and increased concern on unknown effects induced by their release into the aquatic ecosystem. An improved understanding of the environmental transformation processes of NPs of various surface characteristics is hence imperative for risk assessment and management. This study presents results on effects of natural organic matter (NOM) on the environmental transformation and dissolution of metal and metal oxide NPs of different surface and solubility properties in synthetic freshwater (FW) with and without NOM. Adsorption of NOM was evident on most of the studied NPs, except Sb and Sb2O3, which resulted in the formation of negatively charged colloids of higher stability and smaller size distribution compared with the same NPs in FW only. The dissolution rate of the NPs in the presence of NOM correlated with the strength of interactions between the carboxylate group of NOM and the particle surface, and resulted in either no (Mn, Sb, ZnO NPs), increased (Co, Sn NPs) and decreased (Ni, NiO, Sb2O3, Y2O3 NPs) levels of dissolution. One type of metal NP from each group (Mn, Ni, Sn) were investigated to assess whether observed differences in adsorption of NOM and dissolution would influence their ecotoxic potency. The results showed Mn, Ni, and Sn NPs to generate intracellular reactive oxygen species (ROS) in a time and dose-dependent manner. The extent of ROS generation in FW was similar for both Mn and Ni NPs but higher for Sn NPs. These findings are possibly related to interactions and infiltration of the NPs with the cells, which lead to redox imbalances which could induce oxidative stress and cell damage. At the same time, the presence of NOM generally reduced the intracellular ROS generation by 20-40% for the investigated NPs and also reduced cytotoxicity of Sn NPs, which can be attributed to the stronger interaction of carboxylate groups of NOM with the surface of the NPs.
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40. |
- Latvala, Siiri, et al.
(författare)
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Nickel release, ROS generation and toxicity of Ni and NiO micro- and nanoparticles
- 2016
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 11:7
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Tidskriftsartikel (refereegranskat)abstract
- Occupational exposure to airborne nickel is associated with an elevated risk for respiratory tract diseases including lung cancer. Therefore, the increased production of Ni-containing nanoparticles necessitates a thorough assessment of their physical, chemical, as well as toxicological properties. The aim of this study was to investigate and compare the characteristics of nickel metal (Ni) and nickel oxide (NiO) particles with a focus on Ni release, reactive oxygen species (ROS) generation, cellular uptake, cytotoxicity and genotoxicity. Four Ni-containing particles of both nano-size (Ni-n and NiO-n) and micron-size (Ni-m1 and Ni-m2) were tested. The released amount of Ni in solution was notably higher in artificial lysosomal fluid (e.g. 80–100 wt% for metallic Ni) than in cell medium after 24h (ca. 1–3 wt% for all particles). Each of the particles was taken up by the cells within 4 h and they remained in the cells to a high extent after 24 h post-incubation. Thus, the high dissolution in ALF appeared not to reflect the particle dissolution in the cells. Ni-m1 showed the most pronounced effect on cell viability after 48 h (alamar blue assay) whereas all particles showed increased cytotoxicity in the highest doses (20–40 μg cm2) when assessed by colony forming efficiency (CFE). Interestingly an increased CFE, suggesting higher proliferation, was observed for all particles in low doses (0.1 or 1 μg cm-2). Ni-m1 and NiO-n were the most potent in causing acellular ROS and DNA damage. However, no intracellular ROS was detected for any of the particles. Taken together, micron-sized Ni (Ni-m1) was more reactive and toxic compared to the nano-sized Ni. Furthermore, this study underlines that the low dose effect in terms of increased proliferation observed for all particles should be further investigated in future studies.
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41. |
- Latvala, Siiri, et al.
(författare)
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Optimization of an air-liquid interface exposure system for assessing toxicity of airborne nanoparticles
- 2016
-
Ingår i: Journal of Applied Toxicology. - : Wiley. - 0260-437X .- 1099-1263.
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Tidskriftsartikel (refereegranskat)abstract
- The use of refined toxicological methods is currently needed for characterizing the risks of airborne nanoparticles (NPs) to human health. To mimic pulmonary exposure, we have developed an air-liquid interface (ALI) exposure system for direct deposition of airborne NPs on to lung cell cultures. Compared to traditional submerged systems, this allows more realistic exposure conditions for characterizing toxicological effects induced by airborne NPs. The purpose of this study was to investigate how the deposition of silver NPs (AgNPs) is affected by different conditions of the ALI system. Additionally, the viability and metabolic activity of A549 cells was studied following AgNP exposure. Particle deposition increased markedly with increasing aerosol flow rate and electrostatic field strength. The highest amount of deposited particles (2.2 μg cm-2) at cell-free conditions following 2 h exposure was observed for the highest flow rate (390 ml min-1) and the strongest electrostatic field (±2 kV). This was estimated corresponding to deposition efficiency of 94%. Cell viability was not affected after 2 h exposure to clean air in the ALI system. Cells exposed to AgNPs (0.45 and 0.74 μg cm-2) showed significantly (P < 0.05) reduced metabolic activities (64 and 46%, respectively). Our study shows that the ALI exposure system can be used for generating conditions that were more realistic for in vitro exposures, which enables improved mechanistic and toxicological studies of NPs in contact with human lung cells.
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42. |
- Lindqvist, Markus, et al.
(författare)
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Plasma glycosylphosphatidylinositol phospholipase D (GPI-PLD) and abdominal aortic aneurysm.
- 2012
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Ingår i: International Journal of Clinical and Experimental Medicine. - 1940-5901. ; 5:4, s. 306-9
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Tidskriftsartikel (refereegranskat)abstract
- Recent reviews state that a circulating biomarker predicting aortic rupture risk would be a powerful tool to stratify patients with small screen-detected abdominal aortic aneurysm (AAA). In a current proteomic pilot-study elevated levels of the enzyme Glycosylphosphatidylinositol-specific phospholipase D (GPI-PLD) was shown in patients with small AAA compared with controls without aneurysm. In the present study we investigated the impact of plasma GPI-PLD as a biomarker in patients with AAA in relation to aneurysm size, and rupture. Plasma GPI-PLD was measured in patients with AAA (nonruptured, n=78 and ruptured, n=55) and controls without aneurysm (n=41) matched by age, sex and smoking habit. The plasma GPI-PLD levels were significantly lower in patients with ruptured compared nonruptured AAA which we interpreted as a result of hemodilution due to hemorrhage in patients with ruptured AAA. The plasma GPI-PLD levels were similar in patients with nonruptured AAA compared to the controls without aneurysm. Furthermore, there was no correlation between plasma GPI-PLD and aneurysm size in the group of patients with nonruptured AAA. In conclusion, the present study fails to show a connection between GPI-PLD and AAA. However, the definite role of GPI-PLD as a predictive marker needs to be further clarified in a follow-up cohort study.
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43. |
- Lindqvist, Markus, et al.
(författare)
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Soluble urokinase plasminogen activator receptor in patients with abdominal aortic aneurysm
- 2012
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Ingår i: Thrombosis Research. - : Elsevier BV. - 0049-3848 .- 1879-2472. ; 130:3, s. 511-513
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: In the present study we investigated the impact of soluble urokinase plasminogen activator receptor (suPAR) as a biomarker in patients with abdominal aortic aneurysm (AAA) in relation to conventional inflammatory markers, aneurysm size, and rupture. Methods: suPAR and conventional inflammatory markers were measured in 119 patients with AAA and 36 controls without aneurysm matched by age, gender and smoking habit. Results: The results support earlier studies suggesting a state of activated inflammatory response in patients with nonruptured AAA as expressed by elevated CRP and IL-6 compared with the controls. In contrast, suPAR showed similar levels in patients with nonruptured AAA compared with the controls. Unexpectedly, all follow-up patients (n = 16) have significant (p<0.001) elevated suPAR levels three years postoperatively compared preoperatively. Conclusions: suPAR does not seem to be a useful biomarker in the AAA disease. The role of the postoperative elevation of suPAR needs to be further elucidated. (C) 2012 Elsevier Ltd. All rights reserved.
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44. |
- Lowe, Troy A., et al.
(författare)
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Chemical Speciation Measurements of Silver Ions in Alkaline Carbonate Electrolytes Using Differential Pulse Stripping Voltammetry on Glassy Carbon Compared With Ion Selective Electrode Measurements
- 2013
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Ingår i: International Journal of Electrochemical Science. - 1452-3981. ; 8:3, s. 3851-3865
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Tidskriftsartikel (refereegranskat)abstract
- Given the increasing incorporation of silver nanoparticles as an antibacterial additive in washing machines and textiles, sensitive methods for accurate determination of Ag+ ions in laundry relevant electrolytes (alkaline carbonate) are required. The most widely reported method, the silver ion selective electrode (ISE), lacked sensitivity and accuracy and was affected by the concentration of Na2CO3 in solution. Differential pulse stripping voltammetry (DPSV) on glassy carbon electrodes (GCE) was therefore investigated as an alternative technique. Surface preparation of the GCE surface was essential and a suitable procedure was developed. A linear response was observed from 0 to 180 mg L-1 with a lower detection limit of 500 ng L-1 (5 nM). DPSV was shown to be significantly more sensitive and accurate in determining the Ag+ activity than the silver ISE technique, particularly below 200 nM.
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45. |
- McCarrick, S., et al.
(författare)
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Toxtracker reporter cell lines as a tool for mechanism-based (Geno)toxicity screening of nanoparticles—metals, oxides and quantum dots
- 2020
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Ingår i: Nanomaterials. - : MDPI AG. - 2079-4991. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- The increased use of nanoparticles (NPs) requires efficient testing of their potential toxic effects. A promising approach is to use reporter cell lines to quickly assess the activation of cellular stress response pathways. This study aimed to use the ToxTracker reporter cell lines to investigate (geno)toxicity of various metal-or metal oxide NPs and draw general conclusions on NP-induced effects, in combination with our previous findings. The NPs tested in this study (n = 18) also included quantum dots (QDs) in different sizes. The results showed a large variation in cytotoxicity of the NPs tested. Furthermore, whereas many induced oxidative stress only few activated reporters related to DNA damage. NPs of manganese (Mn and Mn3O4) induced the most remarkable ToxTracker response with activation of reporters for oxidative stress, DNA damage, protein unfolding and p53-related stress. The QDs (CdTe) were highly toxic showing clearly size-dependent effects and calculations suggest surface area as the most relevant dose metric. Of all NPs investigated in this and previous studies the following induce the DNA damage reporter; CuO, Co, CoO, CdTe QDs, Mn, Mn3O4, V2O5, and welding NPs. We suggest that these NPs are of particular concern when considering genotoxicity induced by metal-and metal oxide NPs.
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46. |
- Mei, Nanxuan, et al.
(författare)
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Food web transfer of cobalt nanoparticles in algae, zooplankton, and fish
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Cobalt (Co) nanoparticles (NPs) may be diffusely dispersed to natural ecosystems from various sources such as traffic settings, and hence eventually end up in aquatic systems, such as lakes and oceans. This has motivated our studies on the transfer of Co NPs through an aquatic food web including algae (Scendesmus sp), zooplankton (Daphnia magna) and fish (Crucian carp, Carassius carassius). The influence of excreted biomolecules from D. magna, potentially adsorbing and forming an eco-corona at the surfaces of the Co NPs, was also investigated from an environmental fate perspective. ATR-FTIR measurements show adsorption of algae constituents and excreted biomolecules onto the Co NPs. The initially adsorbed smaller molecules of the excreted biomolecules were eventually replaced with larger molecules of higher surface affinity, originating from the algae. In tap water (TW) containing algae, less than 1.5% of the Co NPs mass was dissolved within 24 h, mainly as a result of the near neutral pH. Less than 5% of the Co NPs formed heteroagglomerates with algae, which was partly an effect of agglomeration and settling of the Co NPs. The presence of excreted biomolecules in solution did not affect the extent of heteroagglomeration between the Co NPs and the algae. Some Co NPs were transferred to the next trophic level (D. magna) despite the low extent of heteroagglomeration of Co NPs to algae. The Co uptake in D. magna was 300 times larger compared to the control samples (without Co NP), results that were not influenced by the addition of excreted biomolecules to the solution. A significant uptake of Co by the fish was observed in the intestine, without any evident effect of the presence of excreted biomolecules in the solution. No bioaccumulation of Co was observed in the fish feeding on D. magna containing Co NPs, and 10-20% of the Co NP mass was dissolved after 24 h in its simulated gut solution (pH 7.4). In all, extensive agglomeration and sedimentation of the Co NPs and small extent of heteroagglomeration between the Co NPs and the algae resulted in only a small fraction of Co transferred between the algae and D. magna. No significant bioaccumulation of Co NPs was observed in any of the fish organs, even though a small difference was observed in the fish stomachs and intestines. The dissolution findings in the simulated fish stomach solution (pH 7.4) imply that 60% of the Co NPs will dissolve within 24 h if reached this trophic level.
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47. |
- Mei, Nanxuan, et al.
(författare)
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Influence of Biocorona Formation on the Transformation and Dissolution of Cobalt Nanoparticles under Physiological Conditions
- 2019
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Ingår i: ACS Omega. - : American Chemical Society (ACS). - 2470-1343. ; 4:26, s. 21778-21791
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Tidskriftsartikel (refereegranskat)abstract
- Cobalt (Co) nanoparticles (NPs) are produced in different applications and unintentionally generated at several occupational and traffic settings. Their diffuse dispersion may lead to interactions with humans and aquatic organisms via different exposure routes that include their transformation/dissolution in biological media. This paper has investigated the particle stability and reactivity of Co NPs (dispersed by sonication prior to exposure) interacting with selected individual biomolecules (amino acids, polypeptides, and proteins) in phosphate-buffered saline (PBS). No or minor adsorption of amino acids (glutamine, glutamic acid, lysine, and cysteine) was observed on the Co NPs, independent of the functional group and charge. Instead, phosphate adsorption resulted in the formation of a surface layer (a corona) of Co phosphate. The adsorption of larger biomolecules (polyglutamic acid, polylysine, lysozyme, and mucin) was evident in parallel with the formation of Co phosphate. The dissolution of the Co NPs was rapid as 35-55% of the particle mass was dissolved within the first hour of exposure. The larger biomolecules suppressed the dissolution initially compared to exposure in PBS only, whereas the dissolution was essentially unaffected by the presence of amino acids, with cysteine as an exception. The formation of Co phosphate on the NP surface reduced the protective properties of the surface oxide of the Co NPs, as seen from the increased levels of the released Co when compared with the nonphosphate-containing saline. The results underline the diversity of possible outcomes with respect to surface characteristics and dissolution of Co NPs in biological media and emphasize the importance of surface interactions with phosphate on the NP characteristics and reactivity.
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48. |
- Mei, Nanxuan
(författare)
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Transformation/dissolution characteristics of cobalt and welding fume nanoparticles in physiological and environmental media: surface interactions and trophic transfer
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Nanoparticles (NPs) and nanomaterials (NMs) are present everywhere in the environment. They can form both as an act of nature and during human activities. Various kinds of NPs and NMs are engineered for different applications in the ongoing development of nanoscience and technology. Nowadays, concerns have emerged related to potential adverse effects of NPs on human health and the environment. Knowledge related to effects induced by more reactive metal NPs is scarce or even missing in some cases. Such information is crucial for risk assessments. The focus of this doctoral thesis has therefore mainly been placed on reactive metal NPs: stainless steel welding fume particles, cobalt (Co) NPs, and solution combustion synthesized (SCS) Co NPs, to investigate their transformation/dissolution characteristics in environmental and biological media.Environmental interaction studies were performed in terms of adsorption of biomolecules and natural organic matter (NOM) onto the surfaces of the NPs and their influence on dissolution, agglomeration, and size of the NPs in solution. Trophic transfer of Co NPs was investigated in an aquatic food web.The Co NPs rapidly agglomerated and sedimented in solution. Co ions were released from the NPs in both phosphate buffer solution and in freshwater, dissolution processes that were influenced by the adsorption of biomolecules and NOM. The trophic transfer of Co in the aquatic food web was shown to be affected by the extent of both agglomeration and sedimentation. No biomagnification was observed during the trophic transfer, and the addition of excreted biomolecules had no effect on the transfer.The dissolution of stainless steel welding fume particles was studied in PBS. The metal release data could help estimate the risk assessment of stainless steel welding fume particles.
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49. |
- Nordanstig, Joakim, et al.
(författare)
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Mortality with Paclitaxel-Coated Devices in Peripheral Artery Disease.
- 2020
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Ingår i: The New England journal of medicine. - : Massachusetts Medical Society. - 1533-4406 .- 0028-4793. ; 383, s. 2538-46
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Tidskriftsartikel (refereegranskat)abstract
- The results of a recent meta-analysis aroused concern about an increased risk of death associated with the use of paclitaxel-coated angioplasty balloons and stents in lower-limb endovascular interventions for symptomatic peripheral artery disease.We conducted an unplanned interim analysis of data from a multicenter, randomized, open-label, registry-based clinical trial. At the time of the analysis, 2289 patients had been randomly assigned to treatment with drug-coated devices (the drug-coated-device group, 1149 patients) or treatment with uncoated devices (the uncoated-device group, 1140 patients). Randomization was stratified according to disease severity on the basis of whether patients had chronic limb-threatening ischemia (1480 patients) or intermittent claudication (809 patients). The single end point for this interim analysis was all-cause mortality.No patients were lost to follow-up. Paclitaxel was used as the coating agent for all the drug-coated devices. During a mean follow-up of 2.49 years, 574 patients died, including 293 patients (25.5%) in the drug-coated-device group and 281 patients (24.6%) in the uncoated-device group (hazard ratio, 1.06; 95% confidence interval, 0.92 to 1.22). At 1 year, all-cause mortality was 10.2% (117 patients) in the drug-coated-device group and 9.9% (113 patients) in the uncoated-device group. During the entire follow-up period, there was no significant difference in the incidence of death between the treatment groups among patients with chronic limb-threatening ischemia (33.4% [249 patients] in the drug-coated-device group and 33.1% [243 patients] in the uncoated-device group) or among those with intermittent claudication (10.9% [44 patients] and 9.4% [38 patients], respectively).In this randomized trial in which patients with peripheral artery disease received treatment with paclitaxel-coated or uncoated endovascular devices, the results of an unplanned interim analysis of all-cause mortality did not show a difference between the groups in the incidence of death during 1 to 4 years of follow-up. (Funded by the Swedish Research Council and others; ClinicalTrials.gov number, NCT02051088.).
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50. |
- Pradhan, Sulena, et al.
(författare)
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Effect of sonication on particle dispersion, administered dose and metal release of non-functionalized, non-inert metal nanoparticles
- 2016
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Ingår i: Journal of nanoparticle research. - : Springer. - 1388-0764 .- 1572-896X. ; 18:9
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Tidskriftsartikel (refereegranskat)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.]
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