• Journal of Environmental Health Sciences
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• v.38 no.1
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• pp.1-7
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• 2012

Carbon nanotubes (CNTs) stand at the frontier of nanotechnology and are destined to stimulate the next industrial revolution. Rapid increase in their production and use in the technology industry have led to concerns over the effects of CNT on human health and the environment. The prominent use of CNTs in biomedical applications also increases the possibility of human exposure, while properties such as their high aspect ratio (fiber-like shape) and large surface area raise safety concerns for human health if exposure does occur. It is crucial to develop viable alternatives to in vivo tests in order to evaluate the toxicity of engineered CNTs and develop validated experimental models capable of identifying CNTs' toxic effects and predicting their level of toxicity in the human respiratory system. Human lung epithelial cells serve as a barrier at the interface between the surrounding air and lung tissues in response to exogenous particles such as air-pollutants, including CNTs. Monolayer culture of the key individual cell types has provided abundant fundamental information on the response of these cells to external perturbations. However, such systems are limited by the absence of cell-cell interactions and their dynamic nature, which are both present in vivo. In this review, we suggested two viable alternatives to in vivo tests to evaluate the health risk of human exposure to CNTs.

• Proceedings of the SCSK Conference
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• 2003.09b
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• pp.528-528
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• 2003

The present study was undertaken to develop the in vitro sun protection factor(SPF) test method having good correlation with in vivo method using human. 8% homomentyl salicylate, P3 reference standard and commercially available sunscreen products were measured by the in vitro method using SPF 290S analyzer, and the SPFs were compared with the SPFs measured by in vivo test method. In vitro SPFs of 8% HMS and P3 reference standard were 4.59 $\pm$ 0.12 and 14.94 $\pm$ 0.83. There are good correspondence, correlation coefficients were 0.9506 and 0.9769 respectively, between the in vitro and in vivo SPFs for the sunscreen creams and lotions. Correlation coefficients of makeup base/liquid foundation, lotion labled with "shake before use" and compact powder were 0.8812, 0.8632 and 0.5984 respectively. The optimum mixture ratio of compact powder and cream base represents 1:0.8. These results suggest that the in vitro SPF test method will be able to be used as an alternative method for in vivo SPF in case of lotion and cream.

• YAKHAK HOEJI
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• v.47 no.2
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• pp.110-119
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• 2003

The purpose of the present study was to kinetically investigate the carrier-mediated uptake in the hepatic transport of organic anions, and to simulate the ″in vivo counter-transport″ phenomena, using kinetic model which was developed in this study. The condition that the mobility of carrier-ligand complex is greater than that of free carrier is not essential for the occurrence of ″counter-transport″ phenomenon. To examine the inhibitory effects on the initial uptake of a ligand by the liver, it is necessary to judge whether the true counter-transport mechanism (trans-stimulation) is working or not. The initial plasma disappearance curves of a organic anion were then kinetically analyzed based on a flow model, in which the ligand is eliminated only from the peripheral compartment (liver compartment). Moreover, ″in vive counter-transport″ phenomena were simulated based on the perfusion model which incorporated the carrier-mediated transport and the saturable intracellular binding. The ″in vivo counter-transport″ phenomena in the hepatic transport of a organic anion were well demonstrated by incorporating the carrier-mediated process. However, the ″in vivo counter-transport″ phenomena may be also explained by the enhancement of back diffusion due to the displacement of intracellular binding. In conclusion, one should be more cautious in interpreting data obtained from so-called ″in vivo counter-transport″ experiments.

• Restorative Dentistry and Endodontics
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• v.23 no.1
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• pp.433-442
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• 1998

The purpose of this study was to observe the changes of acidity of resin cement(Time Line), glass ionomer cement(GC Fugi Lining LC), zinc phosphate cement(Fleck's zinc cement). zinc oxide eugenol cement(Sultan,Chemists.) in vivo and in vitro. Class I cavities with 3mm depth were prepared on the occlusal surfaces of 20 recently extracted human Mn. molar teeth and 20 human Mn. 3rd molar teeth in oral cavity. The prepared cavities were divided into 4 groups of each 5 teeth using the above 4 cavity liners. Each cement was mixed in accordance with manufacturer's direction at the room temperature of $23^{\circ}{\pm}5^{\circ}C$ and filled into the cavity in a width of 1 mm. The microelectrode of pH meter was inserted into the prepared cavity which was filled with mixed cement, and the acidity of cement was measured for 3 days from the beginning of cement mix in vitro and in vivo. The measured acidity was then statistically analyzed by ANOVA. The results were as follows. 1. In vitro, the pH of zinc oxide eugenol cement was statistically lower than that of the three other groups at 2min, 4min, 6min, 8min, 10min, 12min, 18min, 20min. (p<0.05). 2. The pH of zinc oxide eugenol cement in vivo was statistically higher than that in vitro at 16min,16min, 20min(p<0.05). 3. The pH of zinc phosphate cement in vivo was statistically higher than that in vitro at 4min, 20min(p<0.05). 4. In vitro and in vivo, there was no significant difference in the pH between the resin cement and the glass ionomer cement(p>0.05). 5. The initial acidity was not high, but almost neutral in all kinds of the cements.

• Bulletin of the Korean Chemical Society
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• v.34 no.6
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• pp.1857-1863
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• 2013

Most of biomaterials come in direct contact with the body, making standardized methods of evaluation and validation of biocompatibility an important aspect to biomaterial development. However, biomaterial validation guidelines have not been fully established, until now. This study was to compare the in vitro behavior of osteoblasts cultured on nanomaterial $TiO_2$ surfaces to osteoblast behavior on culture plates. Comparisons were also made to cells grown in conditioned media (CM) that creates an environment similar to the in vivo environment. Comparisons were made between the different growth conditions for osteoblast adhesion, proliferation, differentiation, and functionality. We found that the in vivo-like system of growing cells in concentrated CM provided a good validation method for biomaterial development and in vivo implant therapy. The $TiO_2$ materials were biocompatible, showing similar behavior to that observed in vivo. This study provided valuable information that would aid in the creation of guidelines into standardization and evaluation of biocompatibility in $TiO_2$ biomaterials.

• The Korean Journal of Food And Nutrition
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• v.21 no.2
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• pp.115-120
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• 2008

To develop a new Gugija(Lycium chinensis Mill) product having increased value, the physiological functionality of various commercial Gugija products were investigated. In addition, an in vivo study was performed using spontaneous hypertensive rats(SHR) to examine the anti-hypertension effects of products. The results showed that antioxidant activity was highest in the methanol extract of Gugija leaf pickle(97.7%), and anti-hypertensive angiotensin I -converting enzyme(ACE) inhibitory activity was 80.4% in Gugija doenjang(soybean paste) water extract. Anti-cholesterolemia HMG-CoA reductase inhibitory activity was highest in the methanol extract of Gugija rice cake(66.1 %). However, SOD-like activity was below 30% in most products; and fibrinolytic activity was not detected or was very weak. Ultimately, we selected Gugija tea and Gugija wine as superior anti-hypertensive Gugija products, and subsequent in vivo testing was performed using SHR, comparing the tea and wine to Gugija fruit. Among them, the Gugija fruit demonstrated the best anti-hypertension effects in SHR.

• Journal of Embryo Transfer
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• v.33 no.4
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• pp.281-286
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• 2018

Zona pellucida (ZP), a primarily representative coat of mammalian egg and embryo, has an extremely heterogeneous morphology during different developmental stages. The objective of the present study was to compare the morphological changes of the ZP surface of immature, in vitro and in vivo matured canine oocytes by using scanning electron microscopy (SEM). Canine ovaries were collected from local veterinary hospitals to recover immature oocytes. The ovaries were sliced and the released cumulus oocyte complexes (COCs) were washed with TL-HEPES. The selected COCs were randomly divided into two groups, first group was processed immediately at immature state and the second group was processed 72 h after in vitro maturation, and compared with in vivo derived oocytes. Oocytes were fixed, critical point dried and examined under SEM. The diameters of oocyte and outer holes of the ZP were measured on a total of 249 oocytes; the results were analyzed using One-way ANOVA. Our results showed that, the diameter of immature oocytes significantly differed (p < 0.05) from that of in vivo matured oocytes ($79.60{\pm}0.77{\mu}m$ vs. $101.46{\pm}1.07{\mu}m$, respectively). Similarly, a significant difference (p < 0.05) in the diameters between those of in vitro and in vivo matured oocytes were found ($79.51{\pm}2.36{\mu}m$ vs. $101.46{\pm}1.07{\mu}m$, respectively). Moreover, the diameters of the outer holes of the ZP were significantly (p < 0.05) larger in in vivo matured ($1.48{\pm}0.42{\mu}m$) than in vitro matured for 72 and immature oocytes ($1.10{\pm}0.16$ and $0.43{\pm}0.12{\mu}m$, respectively). Taken together, these data indicates that the ZP surface is related to oocyte maturity in canine.

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.68.1-68.1
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• 2005

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.1359-1360
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• 2010

• Journal of Periodontal and Implant Science
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• v.14 no.1
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• pp.69.2-69.2
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• 1984