Toxicity and health effects of ultrafine particles: Towards an understanding of the relative impacts of different transport modes.

Exposure to particulate matter (PM) has been associated with a wide range of adverse health effects, but it is still unclear how particles from various transport modes differ in terms of toxicity and associations with different human health outcomes. This literature review aims to summarize toxicological and epidemiological studies of the effect of ultrafine particles (UFPs), also called nanoparticles (NPs, <100 nm), from different transport modes with a focus on vehicle exhaust (particularly comparing diesel and biodiesel) and non-exhaust as well as particles from shipping (harbor), aviation (airport) and rail (mainly subway/underground). The review includes both particles collected in laboratory tests and the field (intense traffic environments or collected close to harbor, airport, and in subway).

Lung Cell Toxicity of Metal-Containing Nanoparticles.

Among the various nanomaterials present in society, many contain metals or metal compounds [...

Primary and Secondary Genotoxicity of Nanoparticles: Establishing a Co-Culture Protocol for Assessing Micronucleus Using Flow Cytometry.

Genotoxicity is an important endpoint to assess for understanding the risks associated with nanoparticles (NPs). Most genotoxicity studies performed on NPs have focused on primary genotoxicity analyzed by comet- or micronuclei (MN) assay using microscopic scoring. Here, we established a protocol for a more efficient version of MN assessment using flow cytometry and, importantly, both primary and secondary (inflammation-driven) genotoxicity was assessed.

Adverse Outcome Pathway Development for Assessment of Lung Carcinogenicity by Nanoparticles.

Lung cancer, one of the most common and deadly forms of cancer, is in some cases associated with exposure to certain types of particles. With the rise of nanotechnology, there is concern that some engineered nanoparticles may be among such particles. In the absence of epidemiological evidence, assessment of nanoparticle carcinogenicity is currently performed on a time-consuming case-by-case basis, relying mainly on animal experiments.

Modelled lung deposition and retention of welding fume particles in occupational scenarios: a comparison to doses used in vitro.

Translating particle dose from in vitro systems to relevant human exposure remains a major challenge for the use of in vitro studies in assessing occupational hazard and risk of particle exposure. This study aimed to model the lung deposition and retention of welding fume particles following occupational scenarios and subsequently compare the lung doses to those used in vitro. We reviewed published welding fume concentrations and size distributions to identify input values simulating real-life exposure scenarios in the multiple path particle dosimetry (MPPD) model.

Toxicity evaluation of particles formed during 3D-printing: Cytotoxic, genotoxic, and inflammatory response in lung and macrophage models.

Additive manufacturing (AM) or "3D-printing" is a ground-breaking technology that enables the production of complex 3D parts. Its rapid growth calls for immediate toxicological investigations of possible human exposures in order to estimate occupational health risks. Several laser-based powder bed fusion AM techniques are available of which many use metal powder in the micrometer range as feedstock.

Gold Nanoparticles Dissolve Extracellularly in the Presence of Human Macrophages.

Introduction: Gold nanoparticles (AuNPs) have the potential to be used in various biomedical applications, partly due to the inertness and stability of gold. Upon intravenous injection, the NPs interact with the mononuclear phagocyte system, first with monocytes in the blood and then with macrophages in tissue. The NP-macrophage interaction will likely affect the stability of the AuNPs, but this is seldom analyzed.

Genotoxicity and inflammatory potential of stainless steel welding fume particles: an in vitro study on standard vs Cr(VI)-reduced flux-cored wires and the role of released metals.

Welders are daily exposed to various levels of welding fumes containing several metals. This exposure can lead to an increased risk for different health effects which serves as a driving force to develop new methods that generate less toxic fumes. The aim of this study was to explore the role of released metals for welding particle-induced toxicity and to test the hypothesis that a reduction of Cr(VI) in welding fumes results in less toxicity by comparing the welding fume particles of optimized Cr(VI)-reduced flux-cored wires (FCWs) to standard FCWs.

Impact of mono-culture vs. Co-culture of keratinocytes and monocytes on cytokine responses induced by important skin sensitizers.

Sensitization to a contact allergen brings with it a lifelong risk to develop allergic contact dermatitis. Inflammation is an important part of the skin sensitizing mechanism, and understanding how different haptens stimulate the immune system, as well as the role played by different cell types present in skin, may be helpful for developing optimized models for risk assessment of new chemicals or mixtures. The aim of this study was to compare the cytokine profile following exposure of cells representing keratinocytes (HaCaT), monocytes (THP-1) and a co-culture of these cells to three clinically important skin sensitizers: cobalt (II) chloride (CoCl), methylisothiazolinone (MI) and p-phenylenediamine (PPD).

Adsorption of Horseradish Peroxidase on Metallic Nanoparticles: Effects on Reactive Oxygen Species Detection Using 2',7'-Dichlorofluorescin Diacetate.

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.

Silver Nanoparticles Alter Cell Viability Ex Vivo and in Vitro and Induce Proinflammatory Effects in Human Lung Fibroblasts.

Silver nanoparticles (AgNPs) are commonly used in commercial and medical applications. However, AgNPs may induce toxicity, extracellular matrix (ECM) changes and inflammatory responses. Fibroblasts are key players in remodeling processes and major producers of the ECM.

Transcriptome Profiling and Toxicity Following Long-Term, Low Dose Exposure of Human Lung Cells to Ni and NiO Nanoparticles-Comparison with NiCl.

Production of nickel (Ni) and nickel oxide (NiO) nanoparticles (NPs) leads to a risk of exposure and subsequent health effects. Understanding the toxicological effects and underlying mechanisms using relevant in vitro methods is, therefore, needed. The aim of this study is to explore changes in gene expression using RNA sequencing following long term (six weeks) low dose (0.

Dry Generation of CeO Nanoparticles and Deposition onto a Co-Culture of A549 and THP-1 Cells in Air-Liquid Interface-Dosimetry Considerations and Comparison to Submerged Exposure.

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 CeO NPs (NM-212) in a co-culture of A549 lung epithelial cells and differentiated THP-1 cells in both ALI and submerged conditions.

ToxTracker Reporter Cell Lines as a Tool for Mechanism-Based (geno)Toxicity Screening of Nanoparticles-Metals, Oxides and Quantum Dots.

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.

Silver nanoparticles modulate lipopolysaccharide-triggered Toll-like receptor signaling in immune-competent human cell lines.

Silver (Ag) nanoparticles are commonly used in consumer products due to their antimicrobial properties. Here we studied the impact of Ag nanoparticles on immune responses by using cell lines of monocyte/macrophage and lung epithelial cell origin, respectively. Short-term experiments (24 h) showed that Ag nanoparticles reduced the lipopolysaccharide (LPS)-induced secretion of pro-inflammatory cytokines in THP-1 cells under serum-free conditions.

High variability in toxicity of welding fume nanoparticles from stainless steel in lung cells and reporter cell lines: the role of particle reactivity and solubility.

Millions of people in the world perform welding as their primary occupation resulting in exposure to metal-containing nanoparticles in the fumes generated. Even though health effects including airway diseases are well-known, there is currently a lack of studies investigating how different welding set-ups and conditions affect the toxicity of generated nanoparticles of the welding fume. The aim of this study was to investigate the toxicity of nine types of welding fume particles generated active gas shielded metal arc welding (GMAW) of chromium-containing stainless steel under different conditions and, furthermore, to correlate the toxicity to the particle characteristics.

Inflammation and (secondary) genotoxicity of Ni and NiO nanoparticles.

Nanoparticle-induced genotoxicity can arise through different mechanisms, and generally, primary and secondary genotoxicity can be distinguished where the secondary is driven by an inflammatory response. It is, however, yet unclear how a secondary genotoxicity can be detected using methods. The aim of this study was to investigate inflammation and genotoxicity caused by agglomerated nickel (Ni) and nickel oxide (NiO) nanoparticles and, furthermore, to explore the possibility to test secondary (inflammation-driven) genotoxicity .

Macrophage-Assisted Dissolution of Gold Nanoparticles.

Gold nanoparticles (AuNPs) are readily functionalized and considered biocompatible making them useful in a wide range of applications. Upon human exposure, AuNPs will to a high extent reside in macrophages, cells that are designed to digest foreign materials. To better understand the fate of AuNPs in the human body, their possible dissolution needs to be explored.

Calcium-dependent cyto- and genotoxicity of nickel metal and nickel oxide nanoparticles in human lung cells.

Background: Genotoxicity is an important toxicological endpoint due to the link to diseases such as cancer. Therefore, an increased understanding regarding genotoxicity and underlying mechanisms is needed for assessing the risk with exposure to nanoparticles (NPs). The aim of this study was to perform an in-depth investigation regarding the genotoxicity of well-characterized Ni and NiO NPs in human bronchial epithelial BEAS-2B cells and to discern possible mechanisms.

Mechanistic insight into reactivity and (geno)toxicity of well-characterized nanoparticles of cobalt metal and oxides.

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 CoO) 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.

RNA-sequencing reveals long-term effects of silver nanoparticles on human lung cells.

Despite a considerable focus on the adverse effects of silver nanoparticles (AgNPs) in recent years, studies on the potential long-term effects of AgNPs are scarce. The aim of this study was to explore the effects of AgNPs following repeated low-dose, long-term exposure of human bronchial epithelial cells. To this end, the human BEAS-2B cell line was exposed to 1 µg/mL AgNPs (10 nm) for 6 weeks followed by RNA-sequencing (RNA-Seq) as well as genome-wide DNA methylation analysis.

Size-dependent genotoxicity of silver, gold and platinum nanoparticles studied using the mini-gel comet assay and micronucleus scoring with flow cytometry.

Metallic nanoparticles (NPs) are promising nanomaterials used in different technological solutions as well as in consumer products. Silver (Ag), gold (Au) and platinum (Pt) represent three metallic NPs with current or suggested use in different applications. Pt is also used as vehicle exhaust catalyst leading to a possible exposure via inhalation.

Genotoxic and mutagenic properties of Ni and NiO nanoparticles investigated by comet assay, γ-H2AX staining, Hprt mutation assay and ToxTracker reporter cell lines.

Nickel (Ni) compounds are classified as carcinogenic to humans but the underlying mechanisms are still poorly understood. Furthermore, effects related to nanoparticles (NPs) of Ni have not been fully elucidated. The aim of this study was to investigate genotoxicity and mutagenicity of Ni and NiO NPs and compare the effect to soluble Ni from NiCl .