| 1. |
- Lammel, Tobias, et al.
(författare)
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Dietary uptake and effects of copper in Sticklebacks at environmentally relevant exposures utilizing stable isotope-labeled 65CuCl2 and 65CuO NPs
- 2021
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 757
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Tidskriftsartikel (refereegranskat)abstract
- © 2020 Elsevier B.V. Copper oxide nanoparticles (CuO NPs) accumulating in sediment can be taken up by invertebrates that serve as prey for fish. Thus, it is likely that the latter are exposed to CuO NPs via the gut. However, to this day it is unknown if CuO NPs can be taken up via the gastrointestinal tract and if and in which tissues/organs they accumulate. To address this knowledge gap, we synthesized CuO NPs enriched in the stable isotope 65Cu and incorporated them at low concentration (5 μg 65Cu g−1 ww food) into a practical diet prepared from worm homogenate, which was then fed to Three-spined Stickleback (Gasterosteus aculeatus) for 16 days. For comparison, fish were exposed to a diet spiked with a 65CuCl2 solution. Background Cu and newly taken up 65Cu in fish tissues/organs including gill, stomach, intestine, liver, spleen, gonad and carcass and feces were quantified by ICP-MS. In addition, expression levels of genes encoding for proteins related to Cu uptake, detoxification and toxicity (ctr-1, gcl, gr, gpx, sod-1, cat, mta and zo-1) were measured in selected tissues using RT-qPCR. The obtained results showed that feces of fish fed 65CuO NP-spiked diet contained important amounts of 65Cu. Furthermore, there was no significant accumulation of 65Cu in any of the analyzed internal organs, though 65Cu levels were slightly elevated in liver. No significant modulation in gene expression was measured in fish exposed to 65CuO NP-spiked diet, except for metallothionein, which was significantly upregulated in intestinal tissue compared to control fish. Altogether, our results suggests that dietary absorption efficiency of CuO NPs, their uptake across the gastrointestinal barrier into the organism, and effects on Cu-related genes is limited at low, environmentally relevant exposure doses (0.2 μg 65Cu −1 fish ww day−1).
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| 2. |
- Minelli, Caterina, et al.
(författare)
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Versailles project on advanced materials and standards (VAMAS) interlaboratory study on measuring the number concentration of colloidal gold nanoparticles
- 2022
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Ingår i: Nanoscale. - : Royal Society of Chemistry (RSC). - 2040-3372 .- 2040-3364. ; 14, s. 4690-4704
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Tidskriftsartikel (refereegranskat)abstract
- We describe the outcome of a large international interlaboratory study of the measurement of particle number concentration of colloidal nanoparticles, project 10 of the technical working area 34, "Nanoparticle Populations" of the Versailles Project on Advanced Materials and Standards (VAMAS). A total of 50 laboratories delivered results for the number concentration of 30 nm gold colloidal nanoparticles measured using particle tracking analysis (PTA), single particle inductively coupled plasma mass spectrometry (spICP-MS), ultraviolet-visible (UV-Vis) light spectroscopy, centrifugal liquid sedimentation (CLS) and small angle X-ray scattering (SAXS). The study provides quantitative data to evaluate the repeatability of these methods and their reproducibility in the measurement of number concentration of model nanoparticle systems following a common measurement protocol. We find that the population-averaging methods of SAXS, CLS and UV-Vis have high measurement repeatability and reproducibility, with between-labs variability of 2.6%, 11% and 1.4% respectively. However, results may be significantly biased for reasons including inaccurate material properties whose values are used to compute the number concentration. Particle-counting method results are less reproducibile than population-averaging methods, with measured between-labs variability of 68% and 46% for PTA and spICP-MS respectively. This study provides the stakeholder community with important comparative data to underpin measurement reproducibility and method validation for number concentration of nanoparticles.
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| 3. |
- Monikh, Fazel Abdolahpur, et al.
(författare)
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Engineered nanoselenium supplemented fish diet : toxicity comparison with ionic selenium and stability against particle dissolution, aggregation and release
- 2020
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Ingår i: Environmental Science: Nano. - : Royal Society of Chemistry. - 2051-8153 .- 2051-8161. ; 7:8, s. 2325-2336
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Tidskriftsartikel (refereegranskat)abstract
- Transformation of nutrients to their nano-form, such as selenium (Se) engineered nanonutrients (Se-ENNs), is expected to enhance the absorption of the nutrients into fish and increase the efficiency of the feed. However, dissolution, aggregation, and release of ENNs from the feed matrix may decrease the efficiency of the Se-ENNs. In this study, we provided fish feed supplemented with Se-ENNs which do not aggregate or dissolve and the particles are also not released from the feed matrix. As a proof of principle, we compared the toxicity of a diet containing Se-ENNs of two different sizes (60 nm and 120 nm) with diets containing ionic Se. The adverse effects were measured by monitoring the survival rate, acetylcholinesterase (AChE) levels and swimming behavior of zebrafish over 21 days of feeding with either the Se-ENNs or ionic Se supplemented fish diets. The number size distribution of the 60 nm Se-ENNs in the diet was similar to that in MilliQ water, while the size distribution of the 120 nm Se-ENNs in the diet was slightly wider. Ion and particle release from Se-ENNs containing diets in the exposure media was not observed, indicating the stability of the particles in the feed matrices. To determine toxicity, zebrafish (Danio rerio) were nourished using a control diet (without Se and Se-ENNs), Se (sodium selenite) containing diets (with 2.4 or 240 mg Se per kg feed) and Se-ENNs containing diets (with 2.4 or 240 mg Se-ENNs of 60 or 120 nm per kg feed) for 21 days. Both sizes of Se-ENNs were taken up in the fish, however only the 120 nm Se-ENNs were detected in the brains of fish. Zebrafish fed with Se-ENNs supplemented diets (60 and 120 nm) showed normal swimming behavior compared to the control. No significant alteration was determined in the AChE activity of the fish fed with the Se-ENNs supplemented diet. In contrast, feeding the zebrafish with a diet containing 240 mg kg(-1)Se led to lethal effects. These observations clearly depict the potential benefits of using Se-ENNs as nutrients in fish feed.
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| 4. |
- Muelhopt, Sonja, et al.
(författare)
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Characterization of Nanoparticle Batch-To-Batch Variability
- 2018
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Ingår i: Nanomaterials. - : MDPI. - 2079-4991. ; 8:5
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Tidskriftsartikel (refereegranskat)abstract
- A central challenge for the safe design of nanomaterials (NMs) is the inherent variability of NM properties, both as produced and as they interact with and evolve in, their surroundings. This has led to uncertainty in the literature regarding whether the biological and toxicological effects reported for NMs are related to specific NM properties themselves, or rather to the presence of impurities or physical effects such as agglomeration of particles. Thus, there is a strong need for systematic evaluation of the synthesis and processing parameters that lead to potential variability of different NM batches and the reproducible production of commonly utilized NMs. The work described here represents over three years of effort across 14 European laboratories to assess the reproducibility of nanoparticle properties produced by the same and modified synthesis routes for four of the OECD priority NMs (silica dioxide, zinc oxide, cerium dioxide and titanium dioxide) as well as amine-modified polystyrene NMs, which are frequently employed as positive controls for nanotoxicity studies. For 46 different batches of the selected NMs, all physicochemical descriptors as prioritized by the OECD have been fully characterized. The study represents the most complete assessment of NMs batch-to-batch variability performed to date and provides numerous important insights into the potential sources of variability of NMs and how these might be reduced.
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