Pilje Kim

Bio: Pilje Kim is an academic researcher from National Institute of Environmental Research. The author has contributed to research in topics: Toxicity & Inhalation. The author has an hindex of 19, co-authored 86 publications receiving 1121 citations.

Toxicity of zinc oxide nanoparticles in rats treated by two different routes: single intravenous injection and single oral administration.

Abstract: Toxicokinetics of zinc oxide nanoparticles (ZnONP) was studied in rats via a single intravenous (iv) injection and a single oral administration (3 mg/kg or 30 mg/kg), respectively. Blood concentrations of zinc (Zn) were monitored for 7 d and tissue distribution were determined in liver, kidneys, lung, spleen, thymus, brain, and testes. To ascertain the excretion of ZnONP, Zn levels in urine and feces were measured for 7 d. ZnONP were not readily absorbed from the gastrointestinal tract (GIT) after oral administration and were excreted mostly in feces. When the nanoparticles were injected iv to rats at a dose of 30 mg/kg, peak concentration appeared at 5 min but returned to normal range by d 2 (48 h after injection). ZnONP were distributed mainly to liver, kidneys, lung, and spleen, but not to thymus, brain, and testes. The distribution level was significantly decreased to normal by d 7. Feces excretion levels after iv injection supported biliary excretion of ZnONP. In rats injected iv with 30 mg/kg, mitot...

Toxicity of Citrate-Capped Silver Nanoparticles in Common Carp (Cyprinus carpio)

Abstract: Juvenile common carp (Cyprinus carpio) were used as a model to investigate acute toxicity and oxidative stress caused by silver nanoparticles (Ag-NPs). The fish were exposed to different concentrations of Ag-NPs for 48 h and 96 h. After exposure, antioxidant enzyme levels were measured, including glutathione-S-transferase (GST), superoxidase dismutase, and catalase (CAT). Other biochemical parameters and histological abnormalities in different tissues (i.e., the liver, gills, and brain) were also examined. The results showed that Ag-NPs agglomerated in freshwater used during the exposure experiments, with particle size remaining <100 nm. Ag-NPs had no lethal effect on fish after 4 days of exposure. Biochemical analysis showed that enzymatic activities in the brain of the fish exposed to 200 𝜇g/L of Ag-NPs were significantly reduced. Varied antioxidant enzyme activity was recorded in the liver and gills. Varied antioxidant enzyme activity was recorded for CAT in the liver and GST in the gills of the fish. However, the recovery rate of fish exposed to 200 𝜇g/L of Ag-NPs was slower than when lower particle concentrations were used. Other biochemical indices showed no significant difference, except for NH3 and blood urea nitrogen concentrations in fish exposed to 50 𝜇g/L of Ag-NPs. This study provides new evidence about the effects of nanoparticles on aquatic organisms.

Combined repeated-dose toxicity study of silver nanoparticles with the reproduction/developmental toxicity screening test

Abstract: Combined repeated-dose toxicity study of citrate-capped silver nanoparticles (7.9 ± 0.95 nm) with reproduction/developmental toxicity was investigated in rats orally treated with 62.5, 125 and 250 mg/kg, once a day for 42 days for males and up to 52 days for females. The test was performed based on the Organization for Economic Cooperation and Development test guideline 422 and Good Laboratory Practice principles. No death was observed in any of the groups. Alopecia, salivation and yellow discolouration of the lung were observed in a few rats but the symptoms were not dose-dependent. Haematology, serum biochemical investigation and histopathological analysis revealed no statistically significant differences between control group and the treated groups. Toxicity endpoints of reproduction/developmental screening test including mating, fertility, implantation, delivery and foetus were measured. There was no evidence of toxicity.

Toxicity of graphene-family nanoparticles: a general review of the origins and mechanisms

Abstract: Due to their unique physicochemical properties, graphene-family nanomaterials (GFNs) are widely used in many fields, especially in biomedical applications Currently, many studies have investigated the biocompatibility and toxicity of GFNs in vivo and in intro Generally, GFNs may exert different degrees of toxicity in animals or cell models by following with different administration routes and penetrating through physiological barriers, subsequently being distributed in tissues or located in cells, eventually being excreted out of the bodies This review collects studies on the toxic effects of GFNs in several organs and cell models We also point out that various factors determine the toxicity of GFNs including the lateral size, surface structure, functionalization, charge, impurities, aggregations, and corona effect ect In addition, several typical mechanisms underlying GFN toxicity have been revealed, for instance, physical destruction, oxidative stress, DNA damage, inflammatory response, apoptosis, autophagy, and necrosis In these mechanisms, (toll-like receptors-) TLR-, transforming growth factor β- (TGF-β-) and tumor necrosis factor-alpha (TNF-α) dependent-pathways are involved in the signalling pathway network, and oxidative stress plays a crucial role in these pathways In this review, we summarize the available information on regulating factors and the mechanisms of GFNs toxicity, and propose some challenges and suggestions for further investigations of GFNs, with the aim of completing the toxicology mechanisms, and providing suggestions to improve the biological safety of GFNs and facilitate their wide application