• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.449-452
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• 2001

In this study. an efficacy study of Portulaca Extract (PE) and ${\beta}$ -glucan. candidates for cosmetic additives. was pedormed using artificial skin model (AS). The AS consists of collagen gel matrix populated by ATCC human skin fibroblast cell line that is overlaid with epidermal human skin keratinocyte cell line. Cytotoxicity and anti - inflammatory activity of PE and ${\beta}$ -glucan were assessed using monolayer and AS models by measuring cell viability and the secretion of interleukin -1 ${\alpha}$.

• Journal of Microbiology and Biotechnology
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• v.32 no.7
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• pp.869-876
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• 2022

The skin, which is the largest organ of the human body, is in direct contact with pollutants in the surrounding atmosphere. Meanwhile, 1-nitropyrene (1-NP), the most abundant nitro-polycyclic aromatic hydrocarbon found in particulate matter, is known to have carcinogenic effects; however, studies on its toxicity in human and canine skin are still needed. In this study, we investigated 1-NP-induced apoptosis and inflammatory pathways in HaCaT cells. In addition, we also measured the cytoprotective effect of methyl gallate (MG), which is widely distributed in medicinal and edible plants and is well known for its anti-inflammatory and antioxidant properties. MG inhibited 1-NP-induced cell death and apoptosis pathways, including the cleavage of PARP and activation of caspase-3, -7, and -9. MG also suppressed 1-NP-induced COX-2 expression and phosphorylation of mitogen-activated protein kinases (MAPKs) and MAPK kinases (MAPKKs). Our findings suggest that 1-NP induces skin toxicity in human and canine through apoptosis and inflammatory responses, and moreover, that this can be prevented by treatment with MG.

• Environmental Analysis Health and Toxicology
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• v.29
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• pp.4.1-4.10
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• 2014

Objectives Effects of nanoparticles including zinc oxide nanoparticles, titanium oxide nanoparticles, and their mixtures on skin corrosion and irritation were investigated by using in vitro 3D human skin models ($KeraSkin^{TM}$) and the results were compared to those of an in vivo animal test. Methods Skin models were incubated with nanoparticles for a definite time period and cell viability was measured by the 3-(4, 5-dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide method. Skin corrosion and irritation were identified by the decreased viability based on the pre-determined threshold. Results Cell viability after exposure to nanomaterial was not decreased to the pre-determined threshold level, which was 15% after 60 minutes exposure in corrosion test and 50% after 45 minutes exposure in the irritation test. IL-$1{\alpha}$ release and histopathological findings support the results of cell viability test. In vivo test using rabbits also showed non-corrosive and non-irritant results. Conclusions The findings provide the evidence that zinc oxide nanoparticles, titanium oxide nanoparticles and their mixture are 'non corrosive' and 'non-irritant' to the human skin by a globally harmonized classification system. In vivo test using animals can be replaced by an alternative in vitro test.

• Toxicological Research
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• v.32 no.4
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• pp.311-316
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• 2016

Effects of nanoparticles (NPs) on skin corrosion and irritation using three-dimensional human skin models were investigated based on the test guidelines of Organization for Economic Co-operation and Development (OECD TG431 and TG439). EpiDerm$^{TM}$ skin was incubated with NPs including those harboring iron (FeNPs), aluminum oxide (AlNPs), titanium oxide (TNPs), and silver (AgNPs) for a defined time according to the test guidelines. Cell viabilities of EpiDerm$^{TM}$ skins were measured by the 3-(4, 5-dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide based method. FeNPs, AlNPs, TNPs, and AgNPs were non-corrosive because the viability was more than 50% after 3 min exposure and more than 15% after 60 min exposure, which are the non-corrosive criteria. All NPs were also non-irritants, based on viability exceeding 50% after 60 min exposure and 42 hr post-incubation. Release of interleukin 1-alpha and histopathological analysis supported the cell viability results. These findings suggest that FeNPs, AlNPs, TNPs, and AgNPs are 'non-corrosive' and 'non-irritant' to human skin by a globally harmonized classification system.

• Proceedings of the SCSK Conference
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• 2003.09a
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• pp.85-96
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• 2003

Normal human skin, constantly challenged by environmental micro-organisms, has an innate ability to fight invading microbes through antimicrobial peptides. These peptides, described in both plant and animal kingdoms are able to inactivate a broad spectrum of micro-organisms. Mammalian defensins constitute one of the most common antimicrobial peptide family. Among the three human beta-defensins hBD1, hBD2 and hBD3 produced in epithelia, only hBD2 and hBD3 are inducible and additionally have been described as expressed by differentiated keratinocytes at site of inflammation and infection. The aims of these studies were to define a cell culture model in which the basal production of hBD could be detected and up-regulated in order to enhance skin auto-protection against micro-organisms. A specific Polymerase Chain Reaction method have been developed for hBD2 and hBD3 mRNA detection in non-differentiated monolayer keratinocytes cell culture. We have been able to demonstrate that in vitro, hBD2 and hBD3 expression in normal human keratinocytes could be detected and enhanced by TNF-alpha and IFN-gamma, in hypercalcic culture conditions. This research opened the possibility of the development of cosmetic active compounds, able to induce the expression of skin natural antibiotic peptides responsible about microflora ecology of the skin.

• 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).

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.3
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• pp.211-216
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• 2016

Micronucleus test is genotoxicity assay for detection of micronuclei in the cytoplasm of interphase cells. The reduction and replacement of in vivo toxicity testing on animals require the development of in vitro models to predict the genotoxicity or other tests for cosmetic products. In this study, we evaluated a genotoxicity assay for topically applied chemicals using a three-dimensional human reconstructed skin model, KeraSkin$^{TM}$. Two genotoxins, mitomycin C (MMC) and methyl methanesulfonate (MMS), induced significant dose-related increases in cytotoxicity and micronuclei induction in the skin model. In contrast, two non-genotoxins, 4-nitrophenol (4-NP) and trichloroethylene (TCE), induced cytotoxicity but not micronucleus formation. In conclusion, micronucleus test using human skin model may be useful for predicting in vitro genotoxic potentials of cosmetic products.

• Imaging Science in Dentistry
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• v.32 no.1
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• pp.11-18
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• 2002

Purpose: To evaluate cultured human artificial skin as an experimental model for studying radiation effects in vitro. Materials and Methods: The skin was constructed by culturing keratinocytes over collagen lattice which made by culturing fibroblasts. Two groups were irradiated to gamma rays at single dose of 25 Gy with or without 3.5% of DMSO. Ultrastructures were investigated by electron microscopy after irradiation. The number of epidermal layers and expression of cytokeratin (CK) 14 & 10 were also seem by light microscopy. Results: At 2 days after irradiation in experimental group without DMSO, necrotic cells were rarely found in the spinosal layer and undercornified cells were visible in the homey layer. Similar findings were also found in experimental group with DMSO but in mild form. The number of epidermal layers in experimental group without DMSO were significantly fewer than other group. CK 14 expressed in all the layer excluding homey layer but CK 10 expressed over 3∼4 basal layers. Such patterns of CK expression were similar to all groups. It is suggested that structures of the keratinocytes and epidermal formation could be disturbed by irradiation in artificial skin and that DMSO can protect these damages. Conclusion : Therefore this work could be used as an organotypic experimental model in vitro using human cells for studying radiation effect in skin. Furthermore structural findings provided in this study could be used as useful basic data in further study using this model.

• Archives of Plastic Surgery
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• v.33 no.5
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• pp.606-611
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• 2006

Purpose: Animal models of a chronic wound are yet to be fully developed, and animal studies on this subject has yet to take place. The purpose of this study is to create the foundation for research on chronic wound healing based on a swine model, the most similar to that of a human. Methods: Three female 2-3 month old 'yolkshires' were used. Total of eight full thickness skin defects, $6{\times}3cm$ sized, were created on the back of each pigs. Three groups were created for comparison; Group I (n=4) was left as they were after full skin thickness excision, while the excised tissues of Group II (n=3) were turned inside out and sutured so that the epidermis would come in contact with the fascia. Group III (n=3) were excised full skin thickness in depth and silicone blocks were implanted in them. Dressing was not practised so that the wounds would be vulnerable to infection. Results: In Group III, the skin contraction rate was the least among the three groups for each three weeks of observation respectively. Also during the three weeks, bacteral colonization was at the highest among the comparison. On the third week, inflammatory cells were still active, but the generations of epidermis and collagen synthesis were detected minimally. Conclusion: The Group III was relatively the most similar model of chronic wounds. and modification of the silicone blocks, could provide us with a very effective chronic skin wound model similar to human.

• Nutritional Sciences
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• v.9 no.3
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• pp.212-226
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• 2006

The involvement of arachidonic acid (AA) metabolizing enzyme, lipoxygenase (LOX), in the development of particular tumors in humans has gradually been acknowledged and LOX has emerged as a novel target to prevent or treat human cancers. In the mouse skin carcinogenesis model, which provides an excellent model to study multistage nature of human cancer development, many studies have shown that some of the LOXs are constitutively upregulated in their expression. Moreover, application of LOX inhibitors effectively reduced tumor burdens, which implicates the involvement of LOX in mouse skin tumor development as well. 8S-LOX is a recently cloned LOX, which is specifically expressed in mouse skin after 12-O-tetradecanoyl-phorbol-13-acetate (TPA) treatment but not in normal skin. Unlike other members of the LOX 'family' expressed in mouse skin, this TPA-induced expression of 8S-LOX is prominent only in the skin of the TPA tumor promotion-sensitive strains of mice (SENCAR, CD-1, and NMRI) but not in the promotion-resistant C57BL/6J mice. This is a very unique phenomenon among strains of mice. Constitutive upregulation of 8S-LOX was also found in early stage papillomas and the expression was gradually reduced as the tumors became malignant. Based on these observations, it has been thought that 8S-LOX is involved in TPA-induced tumor promotion as well as in tumor conversion from papillomas to carcinomas. In accordance with this hypothesis, several studies have suggested possible roles of 8S-hydroxyeicosatetraenoic acid (HETE), an AA metabolite of 8S-LOX, in mouse skin tumor development. A clastogenic activity of 8S-HETE was demonstrated in primary keratinocytes and a close correlation between the levels of etheno-DNA adducts and 8S-HETE during skin carcinogenesis was also reported. On the other hand, it has been reported that 8S-LOX protein expression is restricted to a differentiated keratinocyte compartment Moreover, reported findings on the ability of 8S-HETE to cause keratinocyte differentiation appear to be contrary to the procarcinogenic features of the 8S-LOX expression, presenting a question as to the role of 8S-LOX during mouse skin carcinogenesis. In this review, molecular and biological features of 8S-LOX as well as current views on the functional role of 8S-LOX/8S-HETE during mouse skin carcinogenesis are presented.