Byeong Woo Lee

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Single-wall carbon nanotubes (SWCNTs) were well-dispersed by ultrasonication to conduct an inhalation study. SWCNTs were generated using a pressurised nebuliser with liquid suspension of SWCNTs. Wistar rats were exposed to the well-dispersed SWCNT (diameter of bundle: 0.2 μm; length of bundle: 0.7 μm) for 4 weeks. The low and high mass concentrations of(More)
Multi-walled carbon nanotubes (MWCNTs), dispersed in suspensions consisting mainly of individual tubes, were used for intratracheal instillation and inhalation studies. Rats intratracheally received a dose of 0.2 mg, or 1 mg of MWCNTs and were sacrificed from 3 days to 6 months. MWCNTs induced a pulmonary inflammation, as evidenced by a transient neutrophil(More)
It is important to conduct a risk assessment that includes hazard assessment and exposure assessment for the safe production and handling of newly developed nanomaterials. We conducted an inhalation study of a multi-wall carbon nanotube (MWCNT) as a hazard assessment. Male Wistar rats were exposed to well-dispersed MWCNT for 4 weeks by whole body(More)
Inhalation studies and intratracheal instillation studies using laboratory animals are commonly conducted for pulmonary toxicity tests of nanomaterials. In our study, male Wister rats were exposed to nickel oxide (NiO) particles including a nano-scale, even for aerosols and suspensions, in a 4-week inhalation and intratracheal instillation. Using(More)
OBJECTIVE We examined the pulmonary toxicity of nickel oxide nanoparticle agglomerates in the rat lung following an intratracheal instillation. METHODS The weighted average surface primary diameter of nickel oxide nanoparticles was 8.41 nm, and the count median diameter of nickel oxide nanoparticle agglomerates suspended in saline was 1.34 µm. Male Wistar(More)
In order to investigate the pulmonary toxicity of titanium dioxide (TiO2) nanoparticles, we performed an intratracheal instillation study with rats of well-dispersed TiO2 nanoparticles and examined the pulmonary inflammation and histopathological changes in the lung. Wistar Hannover rats were intratracheally administered 0.2 mg (0.66 mg/kg) and 1.0 mg (3.3(More)
OBJECTIVE In our previous study, we reported that the micron-sized nickel oxide nanoparticle agglomerates induced neutrophil infiltration and the gene expression of the cytokine-induced neutrophil chemoattractant (CINC)-2αβ in a rat lung. In this study, we examined the expression of the CINCs family in the lung using the same rat model exposed to(More)
OBJECTIVE Titanium dioxide nanoparticles are widely used as UV filters in cosmetics and as a photocatalyst. We evaluated pulmonary responses to different crystal forms of TiO2 nanoparticles. METHODS We used 4 different TiO2 samples with similar specific surface areas (anatase, rutile, amorphous, and P25). Each sample was suspended in distilled water and(More)
The pulmonary toxicity of multi-wall carbon nanotubes (MWCNT) were examined by intratracheal instillation. We prepared a well-dispersed MWCNT dispersion including MWCNTs of 3.71 μm geometric average length. The fiber length of most of the MWCNTs in the dispersion was 10 μm or less. The MWCNT dispersion was administered OPEN ACCESS Materials 2012, 5 2834 to(More)
Zinc oxide (ZnO) powders were synthesized by a simple hydrothermal process in the temperature range of 50 to 100 C. Nanocrystallites were formed by a simple hydrothermal route from aqueous solutions of zinc nitrate hexahydrate (Zn(NO3)2·6H2O) and NaOH under controlled process conditions such as precursor concentration (0.07 to 1 mol/L), reaction pH (7 to(More)