The early onset and persistent worsening pulmonary alveolar proteinosis in rats by indium oxide nanoparticles

Polyethylene glycol used as a dispersant potentiates the toxicity of insecticides in mammalian cells rather than insects

Insecticides are used in household products with various dispersants such as polyethylene glycol (PEG) and polyoxyethylene lauryl ether (PLE) to improve solubility. Although certain effects are expected, the combination effects of insecticides and dispersants remain elusive. Here, five different classes of insecticides (i.e., dinotefuran, fipronil, hydramethylnon, indoxacarb, and etofenprox) were dispersed in water, PEG, and PLE, and their lung inflammation potential was evaluated by bronchoalveolar lavage fluid analysis 24 h after intratracheal instillation into the lungs of rats. All chemicals dispersed in water caused no inflammation. However, among the five chemicals dispersed in PEG and PLE, only hydramethylnon showed significant neutrophilic inflammation and hydramethylnon in PEG showed 4-fold higher inflammogenic potential than that in PLE. The in vitro cytotoxic potential of hydramethylnon in PEG was 10-17 fold (in A549) or 12-14 fold (in dTHP-1) higher than that of hydramethylnon in PLE, and greater than 370 fold (in A549) or 65-169 fold (in dTHP-1) higher than that in water. PEG toxicity increased due to the micellar formulation of hydramethylnon in PEG, increasing cellular uptake by simple diffusion. Therefore, the observed potentiation effect highlights that the combination effect of formulation of hydrophobic compounds with dispersants should be carefully evaluated.

The oxidative stress-dependent pulmonary inflammation of inhalable multi-walled carbon nanotube-containing nano-concrete dust and its comparison with conventional concrete dust and DQ12

Nano-concrete, which is an admixture of nanomaterials in concrete recipes, has been investigated to overcome the limitations of existing concrete, such as its stability and strength. However, there is no information on the human health effects of broken-down dust released during the construction and demolition efforts. In this study, we prepared an inhalable fraction of multi-walled carbon nanotube-containing nano-concrete dust and performed comparative toxicity studies with conventional concrete dust and DQ12 using a rat intratracheal instillation model. Although the recipes for concrete and nano-concrete are entirely different, the pulverized dust samples showed similar physicochemical properties, such as 0.46-0.48 µm diameter and chemical composition. Both concrete and nano-concrete dust exhibited similar patterns and magnitudes, representing acute neutrophilic inflammation and chronic active inflammation with lymphocyte infiltration. The toxicity endpoints of the tested particles at both time points showed an excellent correlation with the reactive oxygen species levels released from the alveolar macrophages, highlighting that alveolar macrophages are the primary target cells and that the oxidative stress paradigm is the main toxicity mechanism of the tested particles. In addition, the toxicity potentials of both concrete and nano-concrete dust were more than 10 times lower than that of DQ12.

Current research on ecotoxicity of metal-based nanoparticles: from exposure pathways, ecotoxicological effects to toxicity mechanisms

Metal-based nanoparticles have garnered significant usage across industries, spanning catalysis, optoelectronics, and drug delivery, owing to their diverse applications. However, their potential ecological toxicity remains a crucial area of research interest. This paper offers a comprehensive review of recent advancements in studying the ecotoxicity of these nanoparticles, encompassing exposure pathways, toxic effects, and toxicity mechanisms. Furthermore, it delves into the challenges and future prospects in this research domain. While some progress has been made in addressing this issue, there is still a need for more comprehensive assessments to fully understand the implications of metal-based nanoparticles on the environment and human well-being.

Nose-to-brain translocation and nervous system injury in response to indium tin oxide nanoparticles of long-term low-dose exposures

Indium tin oxide (ITO) is a semiconductor nanomaterial with broad application in liquid crystal displays, solar cells, and electrochemical immune sensors. It is worth noting that, with the gradual increase in worker exposure opportunities, the exposure risk in occupational production cannot be ignored. At present, the toxicity of ITO mainly focuses on respiratory toxicity. ITO inhaled through the upper respiratory tract can cause pathological changes such as interstitial pneumonia and pulmonary fibrosis. Still, extrapulmonary toxicity after nanoscale ITO nanoparticle (ITO NPs) exposure, such as long-term effects on the central nervous system, should also be of concern. Therefore, we set up exposure dose experiments (0 mg·kg-1, 3.6 mg·kg-1, and 36 mg·kg-1) based on occupational exposure limits to treat C57BL/6 mice via nasal drops for 15 weeks. Moreover, we conducted a preliminary assessment of the neurotoxicity of ITO NPs (20-30 nm) in vivo. The results indicated that ITO NPs can cause diffuse inflammatory infiltrates in brain tissue, increased glial cell responsiveness, abnormal neuronal cell lineage transition, neuronal migration disorders, and neuronal apoptosis related to the oxidative stress induced by ITO NPs exposure. Hence, our findings provide useful information for the fuller risk assessment of ITO NPs after occupational exposure.

Size- and oxidative potential-dependent toxicity of environmentally relevant expanded polystyrene styrofoam microplastics to macrophages

Expanded polystyrene (EPS), also known as Styrofoam, is a widespread global pollutant, and its lightweight floating property increases its chances of weathering by abrasion and ultraviolet (UV) irradiation, resulting in microplastics. Herein, we investigated the effects of particle size ((1 µm versus 10 µm), UV irradiation (pristine versus UV oxidation), and origin (secondary versus primary) on the toxicity of Styrofoam microplastics. The target cells used in this study were selected based on human exposure-relevant cell lines: differentiated THP-1 cells for macrophages, Caco-2 for enterocytes, HepG2 for hepatocytes, and A549 for alveolar epithelial cells. In the differentiated THP-1 cells, the levels of cytotoxicity and inflammatory cytokines showed size- (1 µm > 10 µm), UV oxidation- (UV > pristine), and origin- (secondary > primary) dependency. Furthermore, the intrinsic oxidative potential of the test particles was positively correlated with cellular oxidative levels and toxicity endpoints, suggesting that the toxicity of Styrofoam microplastics also follows the oxidative stress paradigm. Additionally, all microplastics induced the activation of the pyrin domain-containing protein 3 (NLRP3) inflammasome and the release of interleukin-1β (IL-1β). These results imply that weathering process can aggravate the toxicity of Styrofoam microplastics due to the increased oxidative potential and decreased particle size.

A case report of Indium lung with progressive emphysema and fibrosis underwent lung unilateral transplantation 20 years after the end of the exposure

BACKGROUND

Indium lung is characterized by interstitial pneumonia and/or emphysema which occurs in indium-tin oxide (ITO) workers. Indium lung is now known to progress after stopping exposure to ITO, but the long-term influences of ITO remain unclear.

CASE PRESENTATION

Forty seven years old, a never-smoker, who had been engaged in an ITO manufacturing process for 8 years. Emphysema was indicated by the medical check-up for ex-ITO workers, and he was diagnosed with indium lung. He underwent partial lung resections for pneumothorax two times, and obstructive pulmonary dysfunction had progressed through the years. He underwent right single lung transplant 20 years after ITO exposure. Pathologically, his lung showed severe distal acinar emphysema and honeycomb change. Fibrosis and destruction of the lung tissue significantly progressed compared to the previous partial resections. Scanning electron microscopy combined with energy dispersive spectroscopy revealed that the deposited particles contained indium and tin. After the transplantation, his respiratory function was improved.

CONCLUSIONS

In this case, ITO resided in the lung tissue for 20 years, and lung tissue destruction kept progressing. Careful medical follow-up is recommended for ITO-workers even if they are asymptomatic.

Beyond GalNAc! Drug delivery systems comprising complex oligosaccharides for targeted use of nucleic acid therapeutics

Nucleic Acid Therapeutics (NATs) are establishing a leading role for the management and treatment of genetic diseases following FDA approval of nusinersen, patisiran, and givosiran in the last 5 years, the breakthrough of milasen, with more approvals undoubtedly on the way. Givosiran takes advantage of the known interaction between the hepatocyte specific asialoglycoprotein receptor (ASGPR) and N-acetyl galactosamine (GalNAc) ligands to deliver a therapeutic effect, underscoring the value of targeting moieties. In this review, we explore the history of GalNAc as a ligand, and the paradigm it has set for the delivery of NATs through precise targeting to the liver, overcoming common hindrances faced with this type of therapy. We describe various complex oligosaccharides (OSs) and ask what others could be used to target receptors for NAT delivery and the opportunities awaiting exploration of this chemical space.

Exposure to Nickel Oxide Nanoparticles Induces Acute and Chronic Inflammatory Responses in Rat Lungs and Perturbs the Lung Microbiome

Nickel oxide nanoparticles (NiO NPs) are highly redox active nanoparticles. They can cause acute and chronic inflammation in rat lungs. Unlike the gut microbiome, the association between the lung microbiome's role and pulmonary inflammatory response to inhaled nanoparticles remains largely unexplored. We aimed to explore the interaction between the lung microbiome and inflammatory responses in rats exposed to NiO NPs. Thirty female Wistar rats were randomly categorized into control and low- (50 cm2/rat), and high- (150 cm2/rat) dose NiO NPs exposure groups. NiO NPs were intratracheally instilled, and cytological, biochemical, proinflammatory cytokine, and lung microbiome analyses of bronchoalveolar lavage fluid were performed at 1 day and 4 weeks after instillation. NiO NPs caused a neutrophilic and lymphocytic inflammatory response in rat lung. We demonstrated that exposure to NiO NPs can alter the lung microbial composition in rats. In particular, we found that more Burkholderiales are present in the NiO NPs exposure groups than in the control group at 1 day after instillation. Dysbiosis in the lung microbiome is thought to be associated with acute lung inflammation. We also suggested that Burkholderiales may be a key biomarker associated with lung neutrophilic inflammation after NiO NPs exposure.

ABCG1 and ABCG4 as key transporters in the development of pulmonary alveolar proteinosis by nanoparticles

Pulmonary alveolar proteinosis (PAP) has been reported in rodents treated with nanoparticles (NPs). However, little is known about the type of NPs producing PAP and their toxicity mechanisms. Here, we assembled seven PAP-inducing NPs and TiO₂ NPs as a negative control. At 1 and 6 months after a single intratracheal instillation in rats, pulmonary inflammation and the gene expression of ATP-binding cassette (ABC) transporters and related genes were evaluated in separated alveolar macrophages (AMs). One month after intratracheal instillation, seven NPs (Eu₂O₃, In₂O₃, Pr₆O₁₁, Sm₂O₃, Tb₄O₇, and NiO) caused PAP, but only In₂O₃ NPs caused persistent PAP at 6 months after treatment. The levels of phospholipids, indicators of PAP, showed good correlations with the gene expression profile of five transporters (ABCA1, ABCB4, ABCB8, ABCG1, and ABCG4), which effluxing phospholipids in AMs. Among them, ABCG1 and ABCG4 might be key transporters involved in PAP development because both showed a negative correlation with the magnitude of PAP, while others might be compensatory transporters for PAP recovery, as they showed a positive correlation. In conclusion, the identification of seven PAP-producing NPs implies that PAP may be an emerging occupational disease and that ABCG1 and ABCG4 may be therapeutic targets for PAP.

Assessment of Occupational Exposure to Indium Dust for Indium-Tin-Oxide Manufacturing Workers

According to recent research, indium nanoparticles (NPs) are more toxic than micro-sized particles. While cases of indium lung disease have been reported worldwide, very little research has been conducted on the occupational exposure to indium NPs. Recently, an indium-related lung disease was reported in Korea, a global powerhouse for display manufacturing. In this study, we conducted an assessment ofoccupational exposure at an indium tin oxide (ITO) powder manufacturing plant, where the first case of indium lung disease in Korea occurred. Airborne dustwas obtained from a worker's breathing zone, and area sampling in the workplace environment was conducted using real-time monitoring devices. Personal samples were analyzed for the indium concentrations in total dust, respirable dust fraction, and NPs using personal NPs respiratory deposition samplers. The total indium concentration of the personal samples was lower than the threshold limit value recommended by the American Conference of Governmental Industrial Hygienists (ACGIH TLV), which was set as occupational exposure limit (OEL). However, the respirable indium concentration exceeded the recently set ACGIH TLV for the respirable fraction of indium dust. The concentration of indium NPs ranged between 0.003 and 0.010 × 10-2 mg/m3, accounting for only 0.4% of the total and 2.7% of the respirable indium particles. This was attributed to the aggregating of NPs at the µm sub-level. Given the extremely low fraction of indium NPs in the total and respirable dust, the current OEL values, set as the total and respirable indium concentrations, do not holistically represent the occupational exposure to indium NPs or prevent health hazards. Therefore, it is necessary to set separate OEL values for indium NPs. This study covers only the process of handling ITO powder. Therefore, follow-up studies need to be conducted on other ITO sputtering target polishing and milling processes, which typically generate more airborne NPs, to further investigate the effects of indium on workers and facilitate the necessary implementation of indium-reducing technologies.

A link between nanoparticles and Parkinson's disease. Which nanoparticles are most harmful?

Nowadays, different kinds of nanoparticles (NPs) are produced around the world and used in many fields and products. NPs can enter the body and aggregate in the various organs including brain. They can damage neurons, in particular dopaminergic neurons in the substantia nigra (SN) and striatal neurons which their lesion is associated with Parkinson's disease (PD). So, NPs can have a role in PD induction along with other agents and factors. PD is the second most common neurodegenerative disease in the world, and in patients, its symptoms progressively worsen day by day through different pathways including oxidative stress, neuroinflammation, mitochondrial dysfunction, α-synuclein increasing and aggregation, apoptosis and reduction of tyrosine hydroxylase positive cells. Unfortunately, there is no effective treatment for PD. So, prevention of this disease is very important. On the other hand, without having sufficient information about PD inducers, prevention of this disease would not be possible. Therefore, we need to have sufficient information about things we contact with them in daily life. Since, NPs are widely used in different products especially in consumer products, and they can enter to the brain easily, in this review the toxicity effects of metal and metal oxide NPs have been evaluated in molecular and cellular levels to determine potential of different kinds of NPs in development of PD.

Prediction of Chronic Inflammation for Inhaled Particles: the Impact of Material Cycling and Quarantining in the Lung Epithelium

On a daily basis, people are exposed to a multitude of health-hazardous airborne particulate matter with notable deposition in the fragile alveolar region of the lungs. Hence, there is a great need for identification and prediction of material-associated diseases, currently hindered due to the lack of in-depth understanding of causal relationships, in particular between acute exposures and chronic symptoms. By applying advanced microscopies and omics to in vitro and in vivo systems, together with in silico molecular modeling, it is determined herein that the long-lasting response to a single exposure can originate from the interplay between the newly discovered nanomaterial quarantining and nanomaterial cycling between different lung cell types. This new insight finally allows prediction of the spectrum of lung inflammation associated with materials of interest using only in vitro measurements and in silico modeling, potentially relating outcomes to material properties for a large number of materials, and thus boosting safe-by-design-based material development. Because of its profound implications for animal-free predictive toxicology, this work paves the way to a more efficient and hazard-free introduction of numerous new advanced materials into our lives.

Toxicity of engineered nanomaterials with different physicochemical properties and the role of protein corona on cellular uptake and intrinsic ROS production

The Organisation for Economic Co-operation and Development has listed thirteen engineered nanomaterials (ENM) in order to investigate their toxicity on human health. Silicon dioxide (SiO₂) and titanium dioxide (TiO₂) are included on that list and we added indium tin oxide (ITO) nanoparticles (NPs) to our study, which is not listed on OECD suggested ENM to be investigated, however ITO NPs has a high potential of industrial production. We evaluate the physicochemical properties of SiO₂ NPs (10-20 nm), TiO₂ nanofibers (NFs; 3 μm length) and ITO NPs (<50 nm) and the impact of protein-corona formation on cell internalization. Then, we evaluated the toxicity of uncoated ENM on human lung epithelial cells exposed to 10 and 50 μg/cm² for 24 h. TiO₂ NFs showed the highest capability to adsorb proteins onto the particle surface followed by SiO₂ NPs and ITO NPs after acellular incubation with fetal bovine serum. The protein adsorption had no impact on Alizarin Red S conjugation, intrinsic properties for reactive oxygen (ROS) formation or cell uptake for all types of ENM. Moreover, TiO₂ NFs induced highest cell alterations in human lung epithelial cells exposed to 10 and 50 μg/cm² while ITO NPs induced moderated cytotoxicity and SiO₂ NPs caused even lower cytotoxicity under the same conditions. DNA, proteins and lipids were mainly affected by TiO₂ NFs followed by SiO₂ NPs with toxic effects in protein and lipids while limited variations were detected after exposure to ITO NPs on spectra analyzed by Fourier Transform Infrared Spectroscopy.