• Proceedings of the Materials Research Society of Korea Conference
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• 2009.11a
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• pp.42.1-42.1
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• 2009

In recent years, it has been tried to develop the efficacy and bioactivity of Calcium Phosphate cements(CPC) as injectable bone substitute (IBS) by reinforcing them through varying the amount in its compositions and relative concentrations or adding other additives. In this study, the biocompatibility of are inforced Calcium Phosphate-Calcium Sulfate injectable bone substitute (IBS)containing poly ($\varepsilon$-caprolactone)PCL microspheres was evaluated which consisted of solution chitosan and Na-citrate as liquid phase and tetra calcium phosphate (TTCP), dicalciumphosphate anhydrous (DCPA) powder as the solid phase. The in vitrobiocompatibility of the IBS was done using MTT assay and Cellular adhesion and spreading studies. The in vitro experiments with simulated body fluid (SBF) confirmed the formation of apatite on sample surface after 7 and 14 days of incubation in SBF. SEM images for one cell morphologies showed that the cellular attachment was good. MG-63 cells were found to maintain their phenotype on samples and SEM micrograph confirmed that cellular attachment was well. In vitro cytotoxicity tests by an extract dilution method showed that the IBS was cytocompatible for fibroblast L-929.

• Reproductive and Developmental Biology
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• v.31 no.2
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• pp.109-113
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• 2007

This study was conducted to evaluate the effect of cytochalasin B (CB) treatment in the activation medium on the development of somatic cell nuclear transfer (SCNT) rat embryos. Fetal fibroblast cells were isolated from a Day 14.5 fetus, and the oocytes for recipient cytoplasm were recovered from 4-week old Sprague Dawley rats. After enucleation and nuclear injection, the reconstructed oocytes were immediately exposed to activation medium consisting of 10 mM $SrCl_2$ with or without CB for 4 hr, and formation of pseudo-pronucleus (PPN) was checked at 18 hr after activation. Then, they were transferred into day 1 pseudopregnant recipients (Hooded Wistar) or cultured for 5 days to check their developmental competence in vivo or in vitro. The number of PPN was not affected by CB treatment during the activation. However, CB treatment supported pre-implantation development of rat SCNT embryos. Embryos generated by the procedures of SCNT were also capable of implanting, with 1 implantation scar found from a recipient following the transfer of 87 SCNT embryos to four foster mothers. The result of the present study shows that rat SCNT embryo can develop to post-implantation stage following treatment with CB.

• Fibers and Polymers
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• v.6 no.3
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• pp.219-223
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• 2005

Water-soluble chitin (WSC) was prepared by carefully deacetylating chitins to about $50\%$ of N-acetyl content. Topical formulations based on WSC were prepared and their effects on wound healing were evaluated on a rabbit ear model. Full-thickness, open skin wounds were made on the ears of rabbits and WSC ointments were embedded in the open wounds. The application of WSC ointments significantly accelerated wound healing and wound contraction. The areas of epithelial-ization and granulation tissues in WSC ointment group are remarkably larger than those in control group (no treatment) and in placebo group (treated with ointment-base materials). A large number of grown granulation tissues including dense fibroblast deposition were observed under the thickened epithelium of the wound treated with WSC ointments. The number of inflammatory cells in WSC ointment group was significantly decreased compared with those in control and placebo groups, indicating that WSC would give low stimuli to wounds and prevent excessive scar formation. Neovascularization was the most prominent in WSC ointment group. Wound contraction in WSC ointment group was much larger than those in control and placebo groups. Overall results demonstrate that the topical formulation based on WSC is considered to become an excellent dressing as a wound healing assistant.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.26 no.1
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• pp.1-5
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• 2017

This study investigated the mechanical tearing of a cell membrane using a nanostructured alumina filter for easy and quick mechanical cell disruption. Nanostructured alumina filters were prepared by a multi-step aluminum anodizing process and nanopore etching process. Six different types of nanostructures were formed on the surface of the nanoporous alumina filters to compare the mechanical cell disruption characteristics according to the shape of the nanostructure. The prepared alumina filter was assembled in a commercial filter holder, and then, NIH3T3 fibroblast cells in a buffer solution were passed through the nanostructured alumina filter at a constant pressure. By measuring the concentration of proteins and DNA, the characteristics of mechanical cell disruption of the nanostructured alumina filter were investigated.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2016.11a
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• pp.118.2-118.2
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• 2016

몇몇의 박테리아들은 바이오필름을 형성하여 그들 스스로를 보호한다. 하지만 바이오필름으로 인해 악취와 질병 등의 문제가 많이 발생되고 있기 때문에 바이오필름을 형성하는 박테리아의 성장을 효율적으로 억제하기 위해 은 나노, 구리 나노입자들이 포함된 다양한 나노스케일의 재료들에 대한 연구가 활발히 진행되어오고 있다. 이들 연구의 주된 목표는 체내에서 독성은 나타내지 않으면서 항균성을 증가시키는 것에 있다. 특히, 구형으로 이루어진 나노입자와 높은 종횡비를 가지는 탄소나노튜브와 같이 차원이 다른 나노물질들의 복합체들은 세포독성을 최소화하면서 특정 박테리아에 대한 항균성을 향상시킬지도 모른다. 이번 연구에서는, 산 처리된 탄소나노튜브에 화학적인 방법을 이용하여 구리 이온을 각각 환원시켜 구리 나노-탄소나노튜브 복합체를 합성하였다. 이들 복합체는 transmission electron microscopy, X-ray diffractometry, energy-dispersive X-ray spectroscopy 를 이용하여 특성이 분석되었고 Methylobacterium spp., Sphingomonas spp. 와 E. coli 에 대하여 항균성이 평가되었다. 추가적으로 구리 나노-탄소나노튜브 복합체는 human fibroblast cells 에 대하여 세포독성이 평가되었고 제작된 마이크로칩 안에 형성된 바이오필름의 성장억제효과가 평가되었다. 결과적으로, 구리 나노-탄소나노튜브 복합체에서 바이오필름을 형성하는 Methylobacterium spp. 에 대하여 특이적으로 항균성을 나타냈으며 바이오필름이 형성된 마이크로칩에서 바이오필름을 제거 하는 것이 확인되었다.

• Biomedical Science Letters
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• v.10 no.3
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• pp.269-273
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• 2004

This study was designed to investigate the effect of ferulic acid on cell viability and cell adhesion activity in normal human gingival fibroblasts. The cell viability and cell adhesion activity of ferulic acid was measured by MTT assay or XTT assay, respectively, after normal human gingival fibroblasts were treated with or without ferulic acid for 48 hours. The cell viability of ferolic acid on normal human gingival fibroblasts did not show any decreasement by MTT assay and also, cell adhesion activity did not decreased by XTT assay, respectively, compared with control after cells were treated with various concentrations of ferolic acid for 48 hours. MTT/sub 50/ and XTT/sub 50/ were 2,130.0 μM and 1,773.7 μM ferolic acid, respectively. These results suggest that ferolic acid is non-toxic to normal human gingival fibroblasts by showing no significant differences in the cell viability and the adhesion activity compared with control by colorimetric assay.

• Biomedical Science Letters
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• v.10 no.3
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• pp.263-268
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• 2004

This study was carried out to evaluate the cytotoxic effect of phenolic compound on normal NIH 3T3 fibrolasts. The colorimetric assay for phenol compound, syringic acid was performed by MTT assay or XTT assay. MTT or XTT assays are known as a very sensitive method in measuring the cytotoxic effect of chemical agents in vitro. In the present study, syringic acid on normal Nlli 3T3 fibroblasts did not show any cytotoxicity for MTT assay or XTT assay compared with control after cells were treated with various concentrations of syringic acid for 48 hours. MTT/sub 50/ and XTT/sub 50/ were 3,340.9 μM and 2,462.4 μM of syringic acid, respectively. From the above the results, it is suggested that phenolic compound of syringic acid did not have any cytotoxicity on normal NIH 3T3 fibroblasts.

• Toxicological Research
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• v.21 no.1
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• pp.71-75
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• 2005

Chrysin (5,7-dihydroxyflavone) is a flavonoid compound contained in many fruits, vegetables and honey. In our experiment, we investigated genotoxicity of chrysin using bacterial reverse mutation assay, chromosomal aberration test, in vivo micronucleus test. In bacterial reverse mutation assay, chrysin did not induce mutagenicity in Salmonella typhimurium TA98, TA100, TA1535, TA1537, TA102 with and without metabolic activation. In chromosome aberration test, chrysin did not also induce structural and numerical abberations regardless of metabolic activation in Chinese hamster lung fibroblast cells. In mouse micronucleus test, no significant increase in the occurrence of micronucleated polychromatic erythrocytes (MNPCE) was observed in ICR male mice orally administered with chrysin at the dose of 0.5, 1.0, 2.0 g/kg body weight. Taken together these results, chrysin has no mutagenic potential in our experiment.

• Korean Journal of Medicinal Crop Science
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• v.19 no.6
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• pp.508-513
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• 2011

The bark of the root and stem of Ulmus davidiana var. japonica has been used as a traditional Korean medicine to treat inflammatory disorders. This plant reportedly shows antioxidant, anticancer, and anti-inflammatory effects. In this study, we investigated the protective effects of Ulmus davidiana var. japonica ethanolic extract (UDE) on UVB irradiation-induced wrinkle in hairless mice. We evaluated for their free radical-scavenging activities against 1,1-diphenyl-2-picrylhydrazyl (DPPH) and the anti-elastase activities, and for their anti-matrix metalloproteinase-1 (MMP-1) activity in human skin fibroblast cells. In the wrinkle measurement and image analysis of skin replicas, the results showed that UDE significantly inhibited wrinkle formation caused by chronic UVB irradiation. These results suggest that UDE has anti-wrinkle activity.

• Korean Journal of Materials Research
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• v.21 no.2
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• pp.125-132
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• 2011

Fibrous chitosan membranes were fabricated as a substrate for skin applications using an electro-spinning process with different solvents and varying concentrations. Scanning electron microscopy (SEM) images confirmed that the formation of the chitosan fibrous membrane in trifluoroacetic acid was better than that in acetic acid. Fourier transform infrared spectroscopy showed that the chitosan fibers were cross-linked with glutaraldehyde, and that the cytotoxicity of the aldehyde groups was reduced by glycine and washing by NaOH and DI water. Chitosan cross-linked fibrous membranes were insoluble in water and could be washed thoroughly to wash away glycine and excess NaOH and prevent the infiltration of other water soluble bio-toxic agents using DI water. MTT assay method was employed to test the cytotoxicity of chitosan membranes during fabricating, treating and washing processes. After the dehydration of cell cultured chitosan membranes, cell attachment behavior on the material was evaluated using SEM method. Effect of the treatment processes on the biocompatibility of the chitosan membranes was shown by comparing of filopodium and lamellipodium of fibroblast cells on grown washed and unwashed chitosan fibrous membrane. The MTT assay and SEM morphology confirmed that the washed chitosan fibrous membrane increased cell attachment and cell growth, and decreased toxicity compared to results for the unwashed chitosan fibrous membrane.