| 1. |
- Abariute, Laura
(author)
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Engineered nanomaterials in in vivo and in vitro models
- 2018
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Doctoral thesis (other academic/artistic)abstract
- Nanotechnology and engineered nanomaterials (ENM) empower existing technologies. One of the great examples are III-V semiconductor nanowires (NW), which have a broad application range. The occupational safety and hazard organizations draw attention to ENM, as their physical and chemical characteristics differ from the ones of bulk materials. Additionally, the NW high aspect ratio geometry is of great concern, since it resembles the morphology of asbestos. Moreover, due to their small size, ENM materials are hard to detect and identify using conventional methods. During ENM technology development and large-scale production, the highest risk of human exposure is via inhalation. Therefore, we need to study how NW affect lung tissue using experimental exposure models. The work in this thesis aimed at filling the knowledge gap in ENM detection and identification, as well as understanding III-V semiconductor NW effects in in vitro and in vitro models.We have used enhanced darkfield microscopy – hyperspectral imaging method to detect and identify ceria nanoparticles in three differently prepared samples, and compared different combinations of data analysis methods. The remaining part of the thesis was devoted to the study of the III-V semiconductor NW effects on cells and tissue in vitro and in vivo. We have exposed two types of cell cultures (primary human lung (SAE) and human lung adenocarcinoma cell line (A549)) to gallium phosphide (GaP) NW. We observed that both type of cells are capable to engulf NW after 2 days, and that NW do not have any effect on the SAE and A549 cell morphology after 7 and 5 days, respectively. The NW concentrations used in this work are not toxic to A549 cells, since we did not see a change in cell mobility, viability or changes in ROS levels. After inhibiting specific endocytosis pathways in A549 cells, we showed that NW are actively taken up via phagocytosis and/or macropinocytosis.Additionally, we have performed in vivo mice exposure to GaP NW via intratracheal instillation. We have observed that NW induce an inflammation and allergic reaction of similar levels as the ones observed after exposure to carcinogenic multiwall carbon nanotubes. Additionally, we show that NW are capable to cross tissue barriers and reach distant organs after 28 days, however without introducing changes to the organ tissues. Lastly, we have performed a pilot study, where we investigated the effect of NW photodiodes on A549 cells. We observed that the presence of light inhibits cell proliferation. Furthermore, we show that the chemical make-up of the photodiodes is important, since some photodiodes dissolve in water based cell culturing media and release toxic compounds.
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| 2. |
- Abariute, Laura, et al.
(author)
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Uptake of nanowires by human lung adenocarcinoma cells
- 2019
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In: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 14:6
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Journal article (peer-reviewed)abstract
- Semiconductor nanowires are increasingly used in optoelectronic devices. However, their effects on human health have not been assessed fully. Here, we investigate the effects of gallium phosphide nanowires on human lung adenocarcinoma cells. Four different geometries of nanowires were suspended in the cell culture for 48 hours. We show that cells internalize the nanowires and that the nanowires have no effect on cell proliferation rate, motility, viability and intracellular ROS levels. By blocking specific internalization pathways, we demonstrate that the nanowire uptake is the result of a combination of processes, requiring dynamin and actin polymerization, which suggests an internalization through macropinocytosis and phagocytosis.
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| 3. |
- Berthing, Trine, et al.
(author)
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Pulmonary toxicity and translocation of gallium phosphide nanowires to secondary organs following pulmonary exposure in mice
- 2023
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In: Journal of Nanobiotechnology. - 1477-3155. ; 21:1
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Journal article (peer-reviewed)abstract
- Background: III-V semiconductor nanowires are envisioned as being integrated in optoelectronic devices in the near future. However, the perspective of mass production of these nanowires raises concern for human safety due to their asbestos- and carbon nanotube-like properties, including their high aspect ratio shape. Indeed, III-V nanowires have similar dimensions as Mitsui-7 multi-walled carbon nanotubes, which induce lung cancer by inhalation in rats. It is therefore urgent to investigate the toxicological effects following lung exposure to III-V nanowires prior to their use in industrial production, which entails risk of human exposure. Here, female C57BL/6J mice were exposed to 2, 6, and 18 µg (0.12, 0.35 and 1.1 mg/kg bw) of gallium phosphide (III-V) nanowires (99 nm diameter, 3.7 μm length) by intratracheal instillation and the toxicity was investigated 1, 3, 28 days and 3 months after exposure. Mitsui-7 multi-walled carbon nanotubes and carbon black Printex 90 nanoparticles were used as benchmark nanomaterials. Results: Gallium phosphide nanowires induced genotoxicity in bronchoalveolar lavage cells and acute inflammation with eosinophilia observable both in bronchoalveolar lavage and lung tissue (1 and 3 days post-exposure). The inflammatory response was comparable to the response following exposure to Mitsui-7 multi-walled carbon nanotubes at similar dose levels. The nanowires underwent partial dissolution in the lung resulting in thinner nanowires, with an estimated in vivo half-life of 3 months. Despite the partial dissolution, nanowires were detected in lung, liver, spleen, kidney, uterus and brain 3 months after exposure. Conclusion: Pulmonary exposure to gallium phosphide nanowires caused similar toxicological effects as the multi-walled carbon nanotube Mitsui-7. Graphical Abstract: [Figure not available: see fulltext.]
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| 4. |
- Krikstolaityte, Vida, et al.
(author)
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Impact of molecular linker size on physicochemical properties of assembled gold nanoparticle mono-/multi-layers and their applicability for functional binding of biomolecules
- 2019
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In: Journal of Colloid and Interface Science. - : Elsevier. - 0021-9797 .- 1095-7103. ; 543, s. 307-316
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Journal article (peer-reviewed)abstract
- In this work the impact of molecular inter-linker size on gold nanoparticle (AuNP) mono-/multilayer structural properties, density and homogeneity has been investigated. These characteristics are of great importance for functional binding of biomolecules. Positively charged high or low molecular weight inter-linkers, poly-L-lysine (PLL) or N-(6-mercapto)hexylpyridinium (MHP), were used to attach negatively charged AuNPs on a planar gold surface as well as to further interlink into a multilayer structure via layer-by-layer deposition. The inter-particle interaction within the assembled AuNP films was adjusted by the ionic strength in the AuNPs dispersions The AuNP layer density and structural/viscoelastic properties were evaluated by the quartz crystal microbalance with dissipation (QCM-D) technique. The validity of the commercial Voigt model, specifically developed for quantitative QCM-D data analysis of homogeneous viscoelastic films, was evaluated by a model independent analysis when comparing the assembled AuNP films with a homogeneous layer of a mucin from bovine submaxillary glands. Both AuNP mono- and multilayers, attached/interlinked via long flexible PLL molecules assembled to denser and more soft/viscous structures compared to those interlinked by short MHP compounds. Thus, PLL-interlinked AuNP mono-/multilayer structures were further investigated as a platform for laccase enzyme functional adsorption via qualitative assessment of bioelectrochemical characteristics of the enzyme. (C) 2019 Elsevier Inc. All rights reserved.
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| 5. |
- Li, Zhen, et al.
(author)
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Cellular traction forces : a useful parameter in cancer research
- 2017
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In: Nanoscale. - : Royal Society of Chemistry (RSC). - 2040-3372 .- 2040-3364. ; 9:48, s. 19039-19044
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Journal article (peer-reviewed)abstract
- The search for new cancer biomarkers is essential for fundamental research, diagnostics, as well as for patient treatment and monitoring. Whereas most cancer biomarkers are biomolecules, an increasing number of studies show that mechanical cues are promising biomarker candidates. Although cell deformability has been shown to be a possible cancer biomarker, cellular forces as cancer biomarkers have been left largely unexplored. Here, we measure traction forces of cancer and normal-like cells at high spatial resolution using a robust method based on dense vertical arrays of nanowires. A force map is created using automated image analysis based on the localization of the fluorescent tips of the nanowires. We show that the force distribution and magnitude differ between MCF7 breast cancer cells and MCF10A normal-like breast epithelial cells, and that monitoring traction forces can be used to investigate the effects of anticancer drugs.
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| 6. |
- Olsson, Therese B, et al.
(author)
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Photovoltaic nanowires affect human lung cell proliferation under illumination conditions
- 2020
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In: Nanoscale. - : Royal Society of Chemistry (RSC). - 2040-3372 .- 2040-3364. ; 12, s. 14237-14244
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Journal article (peer-reviewed)abstract
- Using light to interact with cells is a promising way to steer cell behavior with minimal perturbation. Besides optogenetics, photovoltaic nanostructures such as nanowires can be used to interact with cells using light as a switch. Photovoltaic nanowires have, for instance, been used to stimulate neurons. However, the effects of the photovoltaic activity on cells are still poorly understood and characterized. Here, we investigate the effects of the photovoltaic activity of p-i-n nanowire arrays on A549 human lung adenocarcinoma cells. We have cultured A549 cells on top of vertical arrays of indium phosphide p-i-n nanowires (photovoltaic nanowires), with and without illumination to assess the effects of the nanowire photovoltaic activity on cells. We show that there is a higher proportion of dormant cells when the p-i-n nanowire arrays are illuminated. However, there is no difference in the proportion of dormant cells when the p-i-n nanowires are coated with oxide, which suggests that carrier injection in the cell medium (in this case, the release of electrons from the tip of the nanowires) is an important factor for modulating cell proliferation on photovoltaic nanowires. The results open up for interesting applications of photovoltaic nanowires in biomedicine, such as using them as a dormancy switch.
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