• The Journal of Advanced Prosthodontics
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• v.5 no.4
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• pp.416-422
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• 2013

PURPOSE. This study was performed to define attachment and growth behavior of osteoblast-like cells and evaluate the gene expression on zirconia compared to titanium. MATERIALS AND METHODS. MC3T3-E1 cells were cultured on (1) titanium and (2) zirconia discs. The tetrazolium-based colorimetric assay (MTT test) was used for examining the attachment of cells. Cellular morphology was examined by scanning electron microscopy (SEM) and alkaline phosphatase (ALP) activity was measured to evaluate the cell differentiation rate. Mann-Whitney test was used to assess the significance level of the differences between the experimental groups. cDNA microarray was used for comparing the 20215 gene expressions on titanium and zirconia. RESULTS. From the MTT assay, there was no significant difference between titanium and zirconia (P>.05). From the SEM image, after 4 hours of culture, cells on both discs were triangular or elongated in shape with formation of filopodia. After 24 hours of culture, cells on both discs were more flattened and well spread compared to 4 hours of culture. From the ALP activity assay, the optical density of E1 cells on titanium was slightly higher than that of E1 cells on zirconia but there was no significant difference (P>.05). Most of the genes related to cell adhesion showed similar expression level between titanium and zirconia. CONCLUSION. Zirconia showed comparable biological responses of osteoblast-like cells to titanium for a short time during cell culture period. Most of the genes related to cell adhesion and signal showed similar expression level between titanium and zirconia.

• Korean Journal of Medicinal Crop Science
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• v.19 no.6
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• pp.491-500
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• 2011

Ursolic acid, triterpenoid compound has been shown to stimulate osteoblast differentiation and enhance bone formation. In the present study, we examined the effects of similar triterpenoid compounds, oleanolic acid (OA) and its derivatives, such as oleanolic acid acetate (OAA) and oleanolic acetate methyl ester (OAM) on the bone formation in MC3T3-E1 osteoblast cells. We determined cellular proliferation, alkaline phosphatase (ALP) activity, mineralization, and expression of osteoblast specific genes and mitogen activated protein kinase phosphorylation. Treatment of $0.1-10{\mu}m$ OA, OAA, and OAM increased cellular proliferation, but not significantly increased as compared with dimethyl sulfoxide (DMSO). OA, OAA, and OAM at 5uM concentration enhanced ALP expression, mineralization, and osteocalcin (OCN) mRNA level. In conclusion, OA and its derivatives stimulated the osteoblast differentiation by increasing ALP, mineralization, and OCN mRNA expression. However, there were no significantly difference on osteoblast differentiation among treatment of OA, OAA, and OAM.

• Imaging Science in Dentistry
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• v.38 no.4
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• pp.195-202
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• 2008

Purpose : To characterize the effects of 2-deoxy-D-glucose (2-DG) and quercetin (QCT) on gene expression of osteonectin (ON) and osteopontin (OP) in irradiated MC3T3-El cells. Materials and Methods : When MC3T3-El osteoblastic cells had reached 70-80% confluence, cultures were transferred to a differentiating medium supplemented with 5 mM 2-DG or 10 ${\mu}M$ QCT and then irradiated with 2, 4, 6, and 8 Gy. At various times after irradiation, the cells were analyzed for the expression of bone mineralization genes such as ON and OP. Results : The mRNA expression of both ON and OP was increased according to the culture time in the differentiation medium, and the increase of the genes peaked at 14 days after the differentiation induction. In the case of OP, the increase of mRNA expression was maintained to 28 days after the differentiation, while the mRNA level of ON was reduced to the basal level at the same time. Irradiation adding 2-DG showed a significant peak value in the expression pattern of ON at 4 Gy 7 days after irradiation. Irradiation adding QCT increased the mRNA expression of ON and OP in a dose-dependant manner, but irradiation adding 2-DG did not show any differences between the control and experiments 14 days after irradiation. Irradiation adding QCT increased significantly the expression patterns of ON 21 days after irradiation. Conclusion : The results showed that QCT acted as a radiosensitizer in the gene expression of ON and OP during differentiation of the late stage of irradiated MC3T3-E1 osteoblastic cells in vitro. (Korean J Oral Maxillofac Radiol 2008; 38: 195-202)

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.1001-1002
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• 2009

• Journal of Periodontal and Implant Science
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• v.30 no.1
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• pp.39-52
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• 2000

Polypeptide growth factor belong to a class of potent biologic mediator which regulate cell differentiation, proliferation, migration and metabolism. 1,25-dihydroxyvitamin $D_3$ decrease cell proliferation, and stimulate alkaline phosphatase activity which express in osteoblast during cell differentiation period. IGF-I is known to stimulate cell proliferation and differentiation too. 1,25-dihydroxyvitamin $D_3$ is known to increase IGF-I binding sites and IGF binding protein which inhibite the effect of IGF. The purpose of this study is to evaluate potential role of IGF-I as mediator that control the action of 1,25-dihydroxyvitamin $D_3$. MC3T3-E1 cell were seeded $5{\times}10^5/ml$ at 100mm culture plate in ${\alpha}-MEM$ containing 10% fetal bovine serum. After 48 hour incubation period, medium were changed ${\alpha}-MEM$ containing 5% fetal bovine serum. After 24 hours, $10^{-9}M$ 1,25-dihydroxyvitamin $D_3$ added. Total mRNA was extracted at 0, 6, 24, 48, 72 hour. PRPCR method was programed for the detection of IGF-I mRNA. In the both groups of 1,25-dihydroxy vitamin $D_3$ treated and control, alternative splicing form of IGF-I, IGF-IA and IGF-IB were expressed. In the 1,25-dihydroxyvitamin $D_3$ treated group, IGF-I mRNA expression was matained until 24 hour, there after expression was decresed. MC3T3-E1 cell were seeded $2.5{\times}10^4/ml$ at 24well plate in ${\alpha}-MEM$ containing 10% fetal bovine serum. After 48 hour incubation period, medium were changed ${\alpha}-MEM$ containing 3% fetal bovine serum. After 24 hours, $10^{-9}M$ 1,25-dihydroxyvitamin $D_3$ and 10 ng/ml IGF-I were added separately or together. Cell were cultured for 1 and 3 days, $2{\mu}Ci/ml\;[^3H]$ -thymidine was added for the last 24h of culture of each days. ${[^3H]}$-thymidine incorporation in to DNA was measured and expressed counter per minute(CPM). DNA synthetic activity was significantly decreased by 1,25-dihydroxyvitamin $D_3$ both at 1 day and 3 day, and in the combination group of 1,25-dihydroxyvitamin $D_3$ and IGF-I, DNA synthetic activity was also decreased both at 1 day and 3 days. IGF-I did not affect the DNA synthetic activity compared to control group both at 1 day and 3 day. From the above results, 1,25-dihydroxyvitamin $D_3$ was potent inhibitor of cell proliferaton in MC3T3-E1 cells. It assumed that the effect of 1,25-dihydroxyvitamin $D_3$ on osteoblast proliferation may be mediated in part by decreased level of IGF-I.

• Korean Journal of Environmental Agriculture
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• v.20 no.3
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• pp.155-161
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• 2001

This study was carried out to investigate cytotoxicity of paraquat or bentazone on NIH 3T3 fibroblasts, toxicity of paraquat or bentazone, and compensatory effects of 3-Methylcholanthrene(3-MC) on the rat liver. In order to MTT assay, the $5.0{\times}10^4$ cell/mL of NIH 3T3 fibroblast in each well of 24 multidish were cultured. After 24 hours, the cells were treated with solution of paraquat or bentazone(1, 25, 50, 100 ${\mu}M$ respectively). After the NIH 3T3 fibroblast of all groups were cultured in same condition for 48 hours. MTT assay were performed to evaluate the cytotoxicity of cell organelles. Paraquat or bentazone $MTT_{50}$ were 1668.97 ${\mu}M$ and 1506.97 ${\mu}M$, respectively. These $IC_{50}$ of paraquat or bentazone were decided low cytotoxicity by Borenfreund. In order to observe the toxicity and compensatory effects of paraquat or bentazone on the rat liver, Sprague-Dawley male rats were used as experimental animals and divided into paraquat or bentazone only treated group and simultaneous application group of paraquat or bentazone and 3-MC. At 30 min and 1, 3, 6, 12, 24, 48 and 96 hrs interval after each treatment, the animals were sacrificed by decapitation and liver were immediately removed, immersed in fixatives, and processed with routine method for light microscopic study. Paraffin sections were stained with H-E, PAM and Best Carmine. Under the light microscope, degenerative changes of hepatic lobules were frequently observed in portal area from 3 hrs after paraquat or bentazone treatment. All hepatic cells were induced degenerative change at 12 hrs and more severe degenerative change at 48 hrs after paraquat or bentazone treatment. Especially, hepatic cells of bentazone only treated group were distinctly showed pyknotic. Glycogen granules were increased in portal area at 3 hrs, all hepatic cells at 12 hrs and remarkably increased at 48 hrs after paraquat or bentazone treated group. But hepatic cells of bentazone only treated group were regeneration at 48 hrs from portal area and glycogen granules of hepatic cells of paraquat or bentazone and 3-MC combination treated group showed in central area only at 48 hrs. The results indicate that 3-MC may be decrease paraquat or bentazone cytotoxicity on the rat liver.

• Journal of Periodontal and Implant Science
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• v.30 no.2
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• pp.375-390
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• 2000

The purpose of this study is to evaluate the expression ofIGF-I, considered as the mediator of action of estrogen, and IGF-IA and IGF-IB, alternative slicing form of IGF-I, using $17{\beta}-estradiol$ in MC3T3-E1 cells. We observed the effect on type I collagen and osteopontin gene expression and DNA synthetic activity of MC3T3-E1 cells, added by estrogen, IGF-I and combination and the interactionon proliferation and differentiation of MC3T3-E1 cells. The results were as follows :RT-PCR experiment for observing timedependantIGF-I gene expression patternshowed IGF-IA and IB gene expression in both of control and test group. In these IGF-IA gene expression was appeared predominantly. In control, IGF-I geneexpression level was maintained until 24hr and then decreased gradually. In testgroup, IGF-I gene expression level increased as time goes by. Experiment measuring DNA synthetic activity, as it is added by $17{\beta}-estradiol$, IGF-I and combination, showed that first day , there was the tendency of more increase of synthetic activity in all test group than control but no statical significance(P>0.05), and third day, there was more increase of DNA synthetic activity in $17{\beta}-estradiol$ group and combination group and it was statically significant. (P<0.005) Experiment for observing type I collagen gene expression pattern showed more increase of expression in $17{\beta}-estradiol$ group than control and no significant difference in IGF-I group and combination group. Experiment for observing osteopontin gene expression pattern showed no significant difference in control and test group. In conclusion, $17{\beta}-estradiol$ in MC3T3- E1 cells increased IGF-I gene and DNA synthetic activity simultaneously, therefore it appeared that IGF-I is related to the action of estrogen. Combination treatment of IGF-I and $17{\beta}-estradiol$ has effect on cell proliferation but this effect is lower than IGF-I or $17{\beta}-estradiol$ alone. However, combination treatment has not great effect on type I collagen or osteopontin gene expression thus little effect of cell differentiation.

• Imaging Science in Dentistry
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• v.34 no.3
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• pp.137-144
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• 2004

Purpose: To investigate the effects of low dose irradiation on the calcium content and calcific nodule formation of the MC3T3-El osteoblastic cell line. Materials and Methods: Cells were irradiated with a single dose of 0.2, 0.4 and 0.6 Gy at a dose rate of 5.38 Gy/min using Cs-137 irradiator. After irradiation, the calcium content and calcific nodule formation were examined on the 1st, 2nd, 3rd and 4th week. Results: We did not find any significant difference of total calcium content after irradiation of 0.2, 0.4 and 0.6 Gy when compared with the unirradiated control group. There was no significant difference of total calcium content between 0.2, 0.4 and 0.6 Gy irradiated groups. We found an increased tendency of the calcific nodule formation after irradiation of 0.2, 0.4 and 0.6 Gy when compared with the unirradiated control group without significant difference of calcific nodule formation between 0.2, 0.4 and 0.6 Gy irradiated groups. Conclusion : The results showed an increased tendency of the calcific nodule formation after low dose irradiation. However, this tendency did not increase with the increase of irradiation dose.

• Journal of Periodontal and Implant Science
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• v.31 no.1
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• pp.123-135
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• 2001

Several growth factors and polypeptides were studied for the regeneration of periodontal supporting tissues which had been lost due to periodontal disease. But these are not commonly used for regenerators of bone tissue or alveolar bone, because of the insufficiency of studies on their side effects, genetic engineering for mass production and stability for clinical application. Recently, many natural products, which have advantage of less side effects and possibility of long-term use, have been studied for their capacity and effects of anti-bacterial, anti-inflammatory and regenerative potential or periodontal tissues. Cnidii Rhizoma, Rhinocerotis Cornu and Drynariae Rhizoma have been traditionally used as a drug for treatment of bone disease in oriental medicine. The purpose of this study was to examine the ability of alkaline phosphatase synthesis of MC3T3-E1 cells when above medicines were supplimented. MC3T3-E1 cells were cultured with ${\alpha}-MEM(negative control)$, dexamethasone(positive control), and each natural products for 3 and 5 days. And then ALP synthesis was measured by spectrophotometer for enzyme activity and by naphthol AS-BI staining for morphometry. Except Cnidii Rhizoma, all of the natural products of this study induced higher activity of ALP synthesis than controls. Among them Drynariae Rhizoma induced the highest activity. In the aspects of culturing time, all medicines did not showed the difference between 3 and 5 days, but $10^{-7}g/ml$ group of Rhinocerotis Corun showed significant increase at 3 days than at 5 days. These results indicate that several natural products have a inducing ability of ALP synthesis on osteoblasts.

• Restorative Dentistry and Endodontics
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• v.41 no.3
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• pp.167-175
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• 2016

Objectives: Endodontically treated teeth with insufficient tooth structure are often restored with esthetic restorations. This study evaluated the cytotoxicity and biological effects of yttria partially stabilized zirconia (Y-TZP) blocks in combination with several dental cements. Materials and Methods: Pairs of zirconia cylinders with medium alone or cemented with three types of dental cement including RelyX U200 (3M ESPE), FujiCEM 2 (GC), and Panavia F 2.0 (Kuraray) were incubated in medium for 14 days. The cytotoxicity of each supernatant was determined using 3-(4,5-dimethylthiazole- 2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays on L929 fibroblasts and MC3T3-E1 osteoblasts. The levels of interleukin-6 (IL-6) mRNA were evaluated by reverse transcription polymerase chain reaction (RT-PCR), and IL-6 protein was evaluated by enzyme-linked immunosorbent assays (ELISA). The data were analyzed using one-way ANOVA and Tukey post-hoc tests. A p < 0.05 was considered statistically significant. Results: The MTT assays showed that MC3T3-E1 osteoblasts were more susceptible to dental cements than L929 fibroblasts. The resin based dental cements increased IL-6 expression in L929 cells, but reduced IL-6 expression in MC3T3-E1 cells. Conclusions: Zirconia alone or blocks cemented with dental cement showed acceptable biocompatibilities. The results showed resin-modified glass-ionomer based cement less produced inflammatory cytokines than other self-adhesive resin-based cements. Furthermore, osteoblasts were more susceptible than fibroblasts to the biological effects of dental cement.