• The Journal of Advanced Prosthodontics
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• v.7 no.4
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• pp.278-287
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• 2015

PURPOSE. The aim of this study was to compare the color stability, water sorption and cytotoxicity of thermoplastic acrylic resin for the non-metal clasp dentures to those of thermoplastic polyamide and conventional heat-polymerized denture base resins. MATERIALS AND METHODS. Three types of denture base resin, which are conventional heat-polymerized acrylic resin (Paladent 20), thermoplastic polyamide resin (Bio Tone), thermoplastic acrylic resin (Acrytone) were used as materials for this study. One hundred five specimens were fabricated. For the color stability test, specimens were immersed in the coffee and green tee for 1 and 8 weeks. Color change was measured by spectrometer. Water sorption was tested after 1 and 8 weeks immersion in the water. For the test of cytotoxicity, cell viability assay was measured and cell attachment was analyzed by FE-SEM. RESULTS. All types of denture base resin showed color changes after 1 and 8 weeks immersion. However, there was no significant difference between denture base resins. All specimens showed significant color changes in the coffee than green tee. In water sorption test, thermoplastic acrylic resin showed lower values than conventional heat-polymerized acrylic resin and thermoplastic polyamide resin. Three types of denture base showed low cytotoxicity in cell viability assay. Thermoplastic acrylic resin showed the similar cell attachment but more stable attachment than conventional heat-polymerized acrylic resin. CONCLUSION. Thermoplastic acrylic resin for the non-metal clasp denture showed acceptable color stability, water sorption and cytotoxicity. To verify the long stability in the mouth, additional in vitro studies are needed.

• Journal of the Optical Society of Korea
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• v.18 no.2
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• pp.174-179
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• 2014

Since in vitro neural recording and imaging applications based on a surface plasmon resonance (SPR) technique have expanded dramatically in recent years, cytotoxicity assessment to ensure the biosafety and biocompatibility for those applications is crucial. Here, we report the cytotoxicity of the SPR substrate incorporating a flint glass whose refractive index is larger than that of a conventional crown glass. A high refractive index glass substrate is essential in neural signal detection due to the advantages such as high sensitivity and wide dynamic range. From experimental data using primary hippocampal neurons, it is found that a lead-based flint glass is not appropriate as a neural recording template although the neuron cells are not directly attached to the toxic glass. We also demonstrate that the adhesion layer between the glass substrate and the gold film plays an important role in achieving the substrate stability and the cell viability.

• Advances in Traditional Medicine
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• v.1 no.2
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• pp.45-51
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• 2000

This study was carried out to evaluate cytotoxicity of the methanol extract from Sophora flavescens Ait. against L1210 (lymphocytic leukemia) and $P388D_1$ (lymphoid neoplasma) Cells in vitro. We have determined cytotoxicity by the MTT (3- (4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H- tetrazolium bromide) assay. The order of cytotoxicity of Sophora flavescens Ait. extracts against L1210 and $P388D_1$ cells in vitro is as follows: Fr. 4 > Fr. 3 > Fr. 5 > Fr. 2 > Fr. 1. These results suggest that the fraction 4 of the methanol extracts from Sophora flavescens Ait. may be a valuable choice for the development of antitumor agents. In order to develop an antimicrobial agent, dried Sophora flavescens Ait. was extracted with hot methanol, and then antimicrobial activity (MIC test) was investigated. In this study, the fraction 3 of the methanol extracts from the roots of S. flavescens showed strong growth inhibition activity against gram-positive and gram-negative bacteria (MIC, $3.125\;{\mu}g/ml$) such as S. mutans, S. epidermidis and P. putida. These results indicate that fractions 3 and 4 inhibit tumor cells and bacteria.

• Journal of Apiculture
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• v.33 no.4
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• pp.277-282
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• 2018

Ethanol extracted propolis (EEP) was mixed with honey (honeypolis) to dissolve well in water and in vitro skin irritation test was conducted. In vitro method is designed to predict and classify the skin irritation potential of a chemical by assessment of its effect on $EpiDerm^{TM}$, a reconstituted three-dimensional human epidermis model. Cytotoxicity is expressed as the reduction of mitochondrial dehydrogenase activity measured by formazan production from MTT after a 60 min exposure period. In this study under the given conditions honeypolis showed no irritant effects. Honeypolis meets acceptance criteria if: mean absolute OD 570 nm of the three negative control tissues is ${\geq}0.8$ and ${\leq}2.8$, mean relative tissue viability of the three positive control tissues is ${\leq}20%$, standard deviation of relative tissue viability obtained from each three concurrently tested tissues is ${\leq}18%$. Honeypolis is therefore classified as "non-irritant" in accordance with UN GHS "No Category".

• Journal of Microbiology and Biotechnology
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• v.17 no.9
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• pp.1573-1578
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• 2007

An increasing number of applications is being developed for the use of nanoparticles in various fields. We investigated possible toxicities of nanoparticles in cell culture and in mice. Nanoparticles tested were Zn (300 nm), Fe (100 nm), and Si (10-20, 40-50, and 90-110 nm). The cell lines used were brain, liver, stomach, and lung from humans. In the presence of nanopaticles, mitochodrial activity decreased zero to 15%. DNA contents decreased zero to 20%, and glutathione production increased zero to 15%. None of them showed a dose dependency. Plasma membrane permeability was not altered by nanoparticles. In the case of Si, different sizes of the nanoparticles did not affect cytotoxicity. The cytotoxicity was also shown to be similar in the presence of micro-sized ($45\;{\mu}m$) Si particles. Organs from mice fed with nanoparticles showed nonspecific hemorrhage, lymphocytic infiltration, and medullary congestion. A treatment with the micro-sized particle showed similar results, suggesting that the acute in vivo toxicity was not altered by nano-sized particles.

• The Journal of Korean Medicine
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• v.19 no.2
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• pp.313-325
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• 1998

The effect of Holotrichia on natural killer cell activity in normal mouse were studied. 1. The oral administration of Holotrichia increased spleen weight about 21.1% and also cell numbers of spleen compared to control mice group. 2. The cytotoxicity of effector cell was most effectively induced in a ratio of 50 : 1(effector/target cell). 3. Cytotoxicity of effector cells was. increased about 24% as compared with control group in in vivo test. 4. On the other hand, the administration of Holotrichia original solution showed significant increase the cytotoxicity. The cytotoxicity was increased concentration dependently. 5. The cytotoxicity by $^{3}H-thymidine$ incorporation assay showed similar effect with LDH enzyme method. 6. In the purified NK cells, the cytotoxicity was increased about 31% as compared with control group in in vivo system and the ratio of cytotoxicity was generally more increased than that of partially purified NK cell. 7. In vitro experimet of the purified NK cells, the cytotoxicity was increased 11.8% as compared with control group and the ratio of cytotoxicity was also more increased than that of partially purified NK cell. These results suggest that Holotrichia is administrated to mice with malignant tumors, the increase of NK cell activity may occur and affect tumor cells.

• Journal of Environmental Health Sciences
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• v.41 no.1
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• pp.17-23
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• 2015

Objectives: The cytotoxcities of Au, Ag, SWCNT, $SiO_2$, and ZnO nanomaterials were evaluated in order to assess their potential toxicological effects in in vitro cell models using colony forming efficiency (CFE) assay. Methods: The CFE assay of the test materials was carried out on Hep G2 cells. The size distribution of nanomaterials was studied by transmission electron microscopy (TEM). Changes in cell viability after treatment with a toxicant will result in a decreased number of colonies formed in comparison to solvent. Results: The TEM images show that all the particles except SWCNT and ZnO can be considered approximately spherical. The gold and $SiO_2$ nanoparticles show no response (no toxicity) in concentration response experiments. A statistically significant toxic effect was found in Hep G2 cells treated with Ag, SWCNT and ZnO nanomaterials. Conclusion: In this study, we considered CFE assay to be a promising test for screening studies for cytotoxicity with physicochemical analysis.

• Biomolecules & Therapeutics
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• v.3 no.3
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• pp.242-244
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• 1995

In vitro cell culture system has been proposed as a promising alternative model to in vivo skin irritation test. These studies were performed to screen the cytotoxicity effects of surfactants using normal human skin fibroblasts. Cell membrane integrity assessed by the leakage of lactate dehydrogenase (LDH) and mitochondrial integrity by MTT [3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromides reduction test were affected in a dose dependent manner. The irritation potential of surfactants to human skin patch test, and the changes of capillary permeability by rabbit intradermal safety test were assessed as in vivo methods. Our results suggest that LDH leakage assay and MTT reduction test using cultured human fibroblasts could be predictive for the irritancy of various surfactants in human, and LDH assay is superior correlated with in vivo test (r=0.886) to MTT test with in vivotest (r=0.757).

• Restorative Dentistry and Endodontics
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• v.38 no.4
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• pp.204-209
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• 2013

Objectives: The objective of this in vitro study was to evaluate and compare the cytotoxicity of four different root canal sealers i.e. Apexit Plus (Ivoclar Vivadent), Endomethasone N (Septodont), AH-26 (Dentsply) and Pulpdent Root Canal Sealer (Pulpdent), on a mouse fibroblast cell line (L929). Materials and Methods: Thirty two discs for each sealer (5 mm in diameter and 2 mm in height) were fabricated in Teflon mould. The sealer extraction was made in cell culture medium (Dulbecco's Modified Eagle's Medium, DMEM) using the ratio 1.25 $cm^2/mL$ between the surface of the sealer samples and the volume of medium in a shaker incubator. Extraction of each sealer was obtained at 24 hr, 7th day, 14th day, and one month of interval. These extracts were incubated with L929 cell line and 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide (MTT) assay was done. Two-way ANOVA for interaction effects between sealer and time and Post-hoc multiple comparison using Tukey's test across all the 16 different groups were used for statistical analysis. Results: Apexit Plus root canal sealer was significantly less toxic than other sealers (p < 0.05) and showed higher cellular growth than control. Endomethasone N showed mild cytotoxicity. AH-26 showed severe toxicity which became mild after one month while Pulpdent Root Canal Sealer showed severe to moderate toxicity. Conclusions: Apexit Plus was relatively biocompatible sealer as compared to other three sealers which were cytotoxic at their initial stages, however, they became biocompatible with time.

• Biomedical Science Letters
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• v.13 no.4
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• pp.273-278
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• 2007

Stem cells have been the subject of increasing scientific interest because of their utility in numerous biomedical applications. Stem cells are capable of renewing themselves; that is, they can be continuously cultured in an undifferentiated state, giving rise to more specialized cells of the human body. Therefore, stem cells are an important new tools for developing unique, in vitro model systems to test drugs and chemicals and a potential to predict or anticipate toxicity in humans. In the present study, in vitro cultured F3 immortalized human neural stem cell line and in vivo adult Sprague Dawley rats was used to evaluate the cytotoxicity of anticancer drug paclitaxel. In vitro apoptotic activity of paclitaxel was evaluated in F3 cell line by a MTT assay and DAPI test. The cell death was induced with the treatment of 20 nM paclitaxel and chromatin degradation was detected by DAPI staining, which was analyzed by fluorescent microscope. In vivo studies, we also observed nestin immunoreactivity on subventricular zone, which is stem cell rich region in the adult brain of the SD rat. Immunofluorescent staining result shows that pixel intensities of nestin were decreased in a dose dependent manner. These results suggest that paclitaxel is able to induce cytotoxic activity both in F3 neural stem cell line and neural stem cell in SD rat brain.