Polypropylene nanoplastic exposure leads to lung inflammation through p38-mediated NF-κB pathway due to mitochondrial damage.

Background: Polypropylene (PP) is used in various products such as disposable containers, spoons, and automobile parts. The disposable masks used for COVID-19 prevention mainly comprise PP, and the disposal of such masks is concerning because of the potential environmental pollution. Recent reports have suggested that weathered PP microparticles can be inhaled, however, the inhalation toxicology of PP microparticles is poorly understood.

Development of a Nose-only Inhalation Toxicity Test Chamber That Provides Four Exposure Concentrations of Nano-sized Particles.

Using a numerical analysis based on computerized fluid dynamics, a nose-only inhalation toxicity chamber with four different exposure concentrations is designed and validated for flow field uniformity and cross-contamination among the exposure ports for each concentration. The designed flow field values are compared with the measured values from exposure ports located horizontally and vertically. For this purpose, nanoscale sodium chloride particles are generated as test particles and introduced to the inhalation chamber to evaluate the cross-contamination and concentration maintenance among the chambers, for each concentration group.

Blood Biochemical and Hematological Study after Subacute Intravenous Injection of Gold and Silver Nanoparticles and Coadministered Gold and Silver Nanoparticles of Similar Sizes.

Background: To investigate the effect of subacute intravenous administration AgNP (silver nanoparticles, 10 nm) and AuNP (gold nanoparticles, 12.8 nm) and AgNP/AuNP mixture to blood biochemistry, hematology, and platelet coagulation, subacute toxicity study was conducted.

Methods: AuNP and AgNP in which their size distribution was not statistically different, mixed or separate, were injected into the caudal vein of male Sprague-Dawley rats for 4 weeks.

Subacute inhalation toxicity study of synthetic amorphous silica nanoparticles in Sprague-Dawley rats.

Synthetic amorphous silica nanoparticles (SiNPs) are one of the most applied nanomaterials and are widely used in a broad variety of industrial and biomedical fields. However, no recent long-term inhalation studies evaluating the toxicity of SiNPs are available and results of acute studies are limited. Thus, we conducted a subacute inhalation toxicity study of SiNPs in Sprague-Dawley rats using a nose-only inhalation system.

Short-term inhalation study of graphene oxide nanoplates.

Graphene oxides possess unique physicochemical properties with important potential applications in electronics, pharmaceuticals, and medicine. However, the toxicity following inhalation exposure to graphene oxide has not yet been clarified. Therefore, this study conducted a short-term graphene oxide inhalation toxicity analysis using a nose-only inhalation exposure system and male Sprague-Dawley rats.

In vivo genotoxicity evaluation of lung cells from Fischer 344 rats following 28 days of inhalation exposure to MWCNTs, plus 28 days and 90 days post-exposure.

Despite their useful physico-chemical properties, carbon nanotubes (CNTs) continue to cause concern over occupational and human health due to their structural similarity to asbestos. Thus, to evaluate the toxic and genotoxic effect of multi-wall carbon nanotubes (MWCNTs) on lung cells in vivo, eight-week-old rats were divided into four groups (each group = 25 animals), a fresh air control (0 mg/m(3)), low (0.17 mg/m(3)), middle (0.

Evaluation of newly developed nose-only inhalation exposure chamber for nanoparticles.

In this study, a direct-flow-type nose-only exposure chamber developed for inhalation toxicity experiments using a numerical analysis and experiments is evaluated. Maintaining a uniform flow rate and test article concentration are the critical factors when designing an inhalation exposure chamber. Therefore, this study evaluated whether the flow rate and particle size distribution at the injection nozzles at each port could be maintained with a deviation below 10%.