Toxicological Research Division

South Korea

Toxicological Research Division

South Korea
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Kim H.-M.,Yonsei University | Kim M.-K.,Yonsei University | Kim M.-K.,Seoul Womens University | Lee J.-Y.,Yonsei University | And 7 more authors.
Nippon Seramikkusu Kyokai Gakujutsu Ronbunshi/Journal of the Ceramic Society of Japan | Year: 2014

We have evaluated the morphology dependent biological behaviors of calcite particles in simulated body fluid conditions. Two kinds of calcite particles with different morphologies (cubic and spicule) were prepared utilizing different polyol solvents. According to X-ray diffraction, scanning electron microscopy, zeta potential measurement and dynamic light scattering study, two calcite samples had different morphology but other physicochemical parameters like particle size and surface chemistry of two samples were similar. The biological behaviors of two calcites were evaluated in simulated gastric and intestinal condition considering the oral administration of calcite as potential bio-medical applications. Calcium dissolution rate, change in zeta potential and interaction with proteins of differently shaped calcites in simulated biological conditions were evaluated. Spicule shaped calcites showed facilitated surface calcium ion dissolution compared with cubic shaped one in simulated gastric condition. The zeta potential measurement and protein fluorescence quenching assay results revealed that the spicule calcites interacted more actively with biological substances like electrolytes and proteins than cubic shaped one. Scanning electron microscopic images of calcites treated in simulated body fluid exhibited that the biological behaviors of calcites could be mainly determined by the dissolution and particle-biosubstance interaction at the surface of calcite particles. © 2014 The Ceramic Society of Japan. All rights reserved.


Kim K.-M.,Yonsei University | Song J.H.,Yonsei University | Kim M.-K.,Yonsei University | Chung S.-T.,Toxicological Research Division | And 5 more authors.
Molecular and Cellular Toxicology | Year: 2014

Based on increasing interest and demands for nanomaterials in both industrial and academic fields, concerns for their potential toxicity emerged. In order to evaluate their potential toxicity as well as their interaction towards biological substances, it is important to comprehend and to precisely determine their physicochemical properties. In this review, we demonstrate current state-of-art on analytical methods for determining physicochemical parameters of nanomaterials in both powder and suspension states. A brief introduction on the operating principles of each instrument along with literature examples is given. © 2014, The Korean Society of Toxicogenomics and Toxicoproteomics and Springer Science+Business Media Dordrecht.


Xiao C.W.,Nutrition Research Division | Xiao C.W.,University of Ottawa | Wood C.M.,Nutrition Research Division | Weber D.,Food Research Division | And 4 more authors.
Genes and Nutrition | Year: 2014

Accumulation of hepatic lipid droplet (HLD) is the hallmark pathology of non-alcoholic fatty liver disease (NAFLD). This study examined the effects of soy isoflavones (ISF) and different amounts of soy proteins on the accumulation of HLD, lipid metabolism and related gene expression in rats. Weanling Sprague-Dawley rats were fed diets containing either 20 % casein protein without (D1) or with (D2) supplemental ISF (50 mg/kg diet) or substitution of casein with increasing amounts of alcohol-washed soy protein isolate (SPI, 5, 10, and 20 %; D3, D4, D5) for 90 days. Dietary casein (20 %) induced accumulation of HLD in female, but not in male rats. Both soy proteins and ISF remarkably prevented the formation of HLD. Soy proteins lowered hepatic total cholesterol and triglyceride in a dose-dependent manner. Interestingly, soy proteins but not ISF significantly increased free fatty acids in the liver of the female rats compared to D1. Proteomic analysis showed that at least 3 enzymes involved in lipogenesis were down-regulated and 7 proteins related to fatty acid β-oxidation or lipolysis were up-regulated by soy protein over D1. Additionally, 9 differentially expressed proteins identified were related to amino acid metabolism, 5 to glycolysis and 2 to cholesterol metabolism. Dietary ISF and SPI markedly reduced hepatic-peroxisome-proliferator-activated receptor γ2 (PPARγ2) and fat-specific protein 27 (FSP27) in female rats. Overall, this study has shown that partial or full replacement of dietary casein by soy protein or supplementation with soy ISF can effectively prevent the accumulation of HLD. The potential molecular mechanism(s) involved might be due to suppression of lipogenesis and stimulation of lipolysis and down-regulation of PPARγ2 and FSP27. This suggests that consumption of soy foods or supplements might be a useful strategy for the prevention or treatment of fatty liver diseases. © 2013 Her Majesty the Queen in Right of Canada as represented by the Minister of Health.

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