Absence of phagolysosomal activation and high clearance efficiency define the low pulmonary toxicity of short asbestos fibers.

The physicochemical properties of fibers critically determine asbestos pathogenicity, driving inflammation, fibrosis, and lung cancer. The prevailing paradigm in fiber toxicology posits that long and biopersistent fibers pose a greater health risk than short fibers. However, this assumption is debated due to limited studies specifically assessing the pathogenicity of short fibers.

Dynamic biodistribution of inhaled silica particles to extrapulmonary sites: Early and late translocation mechanisms with implication for particle biomonitoring.

An innovative method based on inductively coupled plasma mass spectrometry (ICP-MS) was developed to quantify the time-dependent systemic redistribution pattern of pulmonary-deposited crystalline silica particles by measuring silicon (Si) levels in the lungs, distal organs, and biological fluids. The method was applied in a murine model and validated in blood and urine samples from two occupationally exposed cohorts (miners and porcelain industry workers). In mice, 30 % of silica particles deposited in the lungs via oropharyngeal administration accumulated in extrapulmonary sites in less than 4 months.

A tiered approach to investigate the inhalation toxicity of cobalt substances. Tier 2a: Grouping cobalt compounds based on their capacity to stabilize HIF-1α in human alveolar epithelial cells in vitro.

Excessive inhalation of cobalt (Co) dust can have harmful effects on the respiratory tract, yet all cobalt substances do not have the same potential for inducing toxicity. The prevalent hypothesis is that the potential of Co substances to release Co ions in the organism and in cells drives their toxicity profile. Here, we explored the possibility of grouping Co substances for predicting inhalation toxicity based on in vitro data using the stabilization of hypoxia-inducible factor (HIF)-1α as a read out for intracellular Co ion content.

Monocytic Ontogeny of Regenerated Macrophages Characterizes the Mesotheliomagenic Responses to Carbon Nanotubes.

Macrophages are not only derived from circulating blood monocytes or embryonic precursors but also expand by proliferation. The origin determines macrophage fate and functions in steady state and pathological conditions. Macrophages predominantly infiltrate fibre-induced mesothelioma tumors and contribute to cancer development.

Dietary nanoparticles alter the composition and function of the gut microbiota in mice at dose levels relevant for human exposure.

Background: Nanotechnologies provide new opportunities for improving the safety, quality, shelf life, flavor and appearance of foods. The most common nanoparticles (NPs) in human diet are silver metal, mainly present in food packaging and appliances, and silicon and titanium dioxides used as additives. The rapid development and commercialization of consumer products containing these engineered NPs is, however, not well supported by appropriate toxicological studies and risk assessment.

Systemic effects and impact on the gut microbiota upon subacute oral exposure to silver acetate in rats.

Context: The addition of silver (Ag) to food items, and its migration from food packaging and appliances results in a dietary exposure in humans, estimated to 70-90 µg Ag/day. In view of the well-known bactericidal activity of Ag ions, concerns arise about a possible impact of dietary Ag on the gut microbiota (GM), which is a master determinant of human health and diseases. Repeated oral administration of Ag acetate (AgAc) can also cause systemic toxicity in rats with reported NOAELs of 4 mg AgAc/b.

Femtosecond pulsed laser microscopy: a new tool to assess the in vitro delivered dose of carbon nanotubes in cell culture experiments.

Background: In vitro models are widely used in nanotoxicology. In these assays, a careful documentation of the fraction of nanomaterials that reaches the cells, i.e.

Cationic Nanoliposomes Are Efficiently Taken up by Alveolar Macrophages but Have Little Access to Dendritic Cells and Interstitial Macrophages in the Normal and CpG-Stimulated Lungs.

The purpose of this study was to assess whether cationic nanoliposomes could address tumor vaccines to dendritic cells in the lungs in vivo. Nanoliposomes were prepared using a cationic lipid, dimethylaminoethanecarbamoyl-cholesterol (DC-cholesterol) or dioleoyltrimethylammoniumpropane (DOTAP), and dipalmitoylphosphatidylcholine (DPPC), the most abundant phospholipid in lung surfactant. The liposomes presented a size below 175 nm and they effectively entrapped tumor antigens, an oligodeoxynucletotide containing CpG motifs (CpG) and the fluorescent dye calcein used as a tracer.

Respiratory hazard of Li-ion battery components: elective toxicity of lithium cobalt oxide (LiCoO) particles in a mouse bioassay.

Rechargeable Li-ion batteries (LIB) are increasingly produced and used worldwide. LIB electrodes are made of micrometric and low solubility particles, consisting of toxicologically relevant elements. The health hazard of these materials is not known.

New interplay between interstitial and alveolar macrophages explains pulmonary alveolar proteinosis (PAP) induced by indium tin oxide particles.

Occupational exposure to indium tin oxide (ITO) particles has been associated with the development of severe lung diseases, including pulmonary alveolar proteinosis (PAP). The mechanisms of this lung toxicity remain unknown. Here, we reveal the respective roles of resident alveolar (Siglec-F AM) and recruited interstitial (Siglec-F IM) macrophages contributing in concert to the development of PAP.

CCR2 monocytic myeloid-derived suppressor cells (M-MDSCs) inhibit collagen degradation and promote lung fibrosis by producing transforming growth factor-β1.

Monocytes infiltrating scar tissue are predominantly viewed as progenitor cells. Here, we show that tissue CCR2 monocytes have specific immunosuppressive and profibrotic functions. CCR2 monocytic cells are acutely recruited to the lung before the onset of silica-induced fibrosis in mice.

Does carbonation of steel slag particles reduce their toxicity? An in vitro approach.

Mineral carbonation can stabilize industrial residues and, in the steel industry, may contribute to simultaneously valorize CO2 emissions and slag. We hypothesized that, by restricting the leaching of metals of toxicological concern such as Cr and V, carbonation can suppress the toxicity of these materials. The cytotoxic activity (WST1 assay) of slag dusts collected from a stainless and a Linz-Donawitz (LD) steel plant, before and after carbonation, was examined in J774 macrophages.

Nanometer-long Ge-imogolite nanotubes cause sustained lung inflammation and fibrosis in rats.

Background: Ge-imogolites are short aluminogermanate tubular nanomaterials with attractive prospected industrial applications. In view of their nano-scale dimensions and high aspect ratio, they should be examined for their potential to cause respiratory toxicity. Here, we evaluated the respiratory biopersistence and lung toxicity of 2 samples of nanometer-long Ge-imogolites.

Lung inflammation and thymic atrophy after bleomycin are controlled by the prostaglandin D2 receptor DP1.

Acute lung injury (ALI) can be accompanied by secondary systemic manifestations. In a model of ALI induced by bleomycin (bleo), we examined the response of D prostanoid receptor 1 (DP1)-deficient mice (DP1(-/-)) to better understand these processes. DP1 deficiency aggravated the toxicity of bleo as indicated by enhanced body weight loss, mortality, and lung inflammation including bronchoalveolar permeability and neutrophilia.