• Bulletin of the Korean Chemical Society
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• v.33 no.8
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• pp.2585-2591
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• 2012

A series of heterocyclic chalcone derivatives bearing heterocycles such as thiophene or furan ring as an isostere of benzene ring were carefully prepared, and the influence of heterocycles on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities was systematically investigated. Structure-activity relationships (SAR) analysis showed that the activities of thiophene ring-containing chalcones were higher than those of furan ring-containing chalcones, and the presence of methyl substituent of heterocyclic ring distinctly affected the activities compared with non-substituted heterocycles in an opposite manner, with the 4'-methyl group of thiophene ring increasing activity and the 3'-methyl group of the furan ring decreasing activity. The distinct isosteric effect of heterocycles (i.e., thiophene or furan ring) on radical scavenging activities of heterocyclic chalones was distinctly demonstrated in our work.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.52.1-52.1
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• 2011

In this work, the effect of the addition of bioactive glass in the biocompatibility and mechanical behavior of conventional TTCP/DCPA based bone cement were investigated. The cement was initially modified with chitosan and HPMC which cross-linked with citric acid to improved mechanical properties.The injectable bone substitutes were further modified by adding varying amounts of bioactive glass (0%, 10%, 20% and 30%) and its effects on the biocompatibility of the material were studied. Afterbio-glass powders were mixed with the optimized composition for HPMC and citric acid content,the IBS was incubated at $37^{\circ}C$ at different time intervals and showed progressive formation of HAp with increasing time. Mechanical properties like Vickers hardness and compressive strength were found to increase with the increasing amount of bioactive glass addition and that setting time was shortened. The fabricated IBS morphologies were further characterized using SEM. MTT assay was performed to check the cell cytotoxicity and cell proliferation for 1, 3 and 5 days. Cell morphology, adhesion and proliferation behavior of cell in the IBS by culturing MG-63 cells on the IBS for 20, 60 and 90 mins and 1, 3 and 5 days was also investigated. All the results showed increasing biocompatibility as the bioglass content increased. MTT results found the materials to be cytocompatible and SEM images showed that cells attached and proliferated successfully.

• Journal of Technologic Dentistry
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• v.36 no.3
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• pp.179-184
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• 2014

Purpose: This study was performed to investigate the release behavior of bioactive materials as a BMP-2 embedding on the porous titanium implant. Methods: Porous Ti implant samples were fabricated by sintering of spherical Ti powders in a high vacuum furnace. Specimens diameter and height were 4mm and 10mm. Embedding materials were used to stamp ink. Sectional images, porosity and release behavior of porous Ti implants were evaluated by scanning electron microscope(SEM), mercury porosimeter and UV-Vis-NIR spectrophotometer. Results: Internal pore structure was formed fully open pore. Average pore size and porosity were $8.993{\mu}m$ and 8.918%. Embedding materials were released continually and slowly. Conclusion: Porous Ti implant was fabricated successfully by sintering method. Particles are necking strongly each other and others portions were vacancy. Therefore bioactive materials will be able to embedding to porous Ti implants. If the development of the fusion implant of the bioactive material will be able to have the chance to several patients.

• Journal of Periodontal and Implant Science
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• v.32 no.1
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• pp.187-198
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• 2002

The ultimate goal of periodontal therapy is the regeneration of periodontal tissue which has been lost due to destructive periodontal disease. To achieve periodontal regeneration, various kinds of methods have been investigated and developed, including guided tissue regeneration and bone graft. Bone graft can be catagorized into autografts, allografts, xenografts, bone substitutes. And materials of all types have different biological activity and the capacity for periodontal regeneration, but ideal graft material has not been developed that fits all the requirement of ideal bone graft material. Recently, bioactive glass that has been utilized in plastic surgery is being investigated for application in dental practice. But, there has not been any long-term assessment of bioactive glass when used in periodontal intrabony defects. The present study evaluates the long-term effects of bioactive glass on the periodontal regeneration in intrabony defects of human and the effect of plaqu control on long term treatment results after dividing patients into those who underwent 3-month regular check-up and those who didn't under go regular check-up The clinical effect on 74sites from 17 infrabony pockets of 11 patients were analyzed 36months after treatment. 51 sites which underwent regular check up were classified as the Follow-up group(F/U group), and 23 sites which did not undergo regular check up were classified as Non Follow-up group(Non F/U group). After comparing the probing depth, attachment loss, bone probing depth before and 36months after treatment, the following results could be concluded. 1. The changes of probing pocket depth showed a statistically significant decrease between after baseline and 36 months after treatment in F/U group(1.79${\pm}$0.68mm) and did no show astatistically significant decrease between after baseline and 36months after treatment in Non F/U group(0.61${\pm}$0.54mm) (P<0.05). 2. The changes of loss of attachment showed a statistically significant decrease between after baseline and 36 months after treatment in F/U group(1.44${\pm}$0.74mm) and did no show astatistically significant decrease between after baseline and 36months after treatment in Non F/U group(1.18${\pm}$1.54) (P<0.05). 3. The changes of bone probing depth showed a statistically significant decrease between after baseline and 36 months after treatment in both F/U(1.35${\pm}$0.28) and Non F/U group(0.78${\pm}$0.55mm) (P<0.05). The results suggest that treatment of infrabony defects with bioactive glass resulted in significan reduction of attachment loss and bone probing depth 36months after the treatment. The use of bioactive glass in infrabony defects, combined with regular check-up and proper plaque control generally shows favorable clinical results. This measn that bioactive glass could be a useful bone substitute.

• Mycobiology
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• v.47 no.4
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• pp.512-520
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• 2019

Statistical experimental methods were used to optimize the medium for mass production of a novel laccase3 (Lac3) by recombinant Saccharomyces cerevisiae TYEGLAC3-1. The basic medium was composed of glucose, casamino acids, yeast nitrogen base without amino acids (YNB w/o AA), tryptophan, and adenine. A one-factor-at-a-time approach followed by the fractional factorial design identified galactose, glutamic acid, and ammonium sulfate, as significant carbon, nitrogen, and mineral sources, respectively. The steepest ascent method and response surface methodology (RSM) determined that the optimal medium was (g/L): galactose, 19.16; glutamic acid, 5.0; and YNB w/o AA, 10.46. In this medium, the Lac3 activity (277.04 mU/mL) was 13.5 times higher than that of the basic medium (20.50 mU/mL). The effect of temperature, pH, agitation (rpm), and aeration (vvm) was further examined in a batch fermenter. The best Lac3 activity was 1176.04 mU/mL at 25 ℃, pH 3.5, 100 rpm, and 1 vvm in batch culture.

• Journal of Microbiology and Biotechnology
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• v.30 no.11
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• pp.1651-1658
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• 2020

Since Zika virus (ZIKV) was first detected in Uganda in 1947, serious outbreaks have occurred globally in Yap Island, French Polynesia and Brazil. Even though the number of infections and spread of ZIKV have risen sharply, the pathogenesis and replication mechanisms of ZIKV have not been well studied. ZIKV, a recently highlighted Flavivirus, is a mosquito-borne emerging virus causing microcephaly and the Guillain-Barre syndrome in fetuses and adults, respectively. ZIKV polyprotein consists of three structural proteins named C, prM and E and seven nonstructural proteins named NS1, NS2A, NS2B, NS3, NS4A, NS4B, and NS5 in an 11-kb single-stranded positive sense RNA genome. The function of individual ZIKV genes on the host innate immune response has barely been studied. In this study, we investigated the modulations of the NF-κB promoter activity induced by the MDA5/RIG-I signaling pathway. According to our results, two nonstructural proteins, NS2A and NS4A, dramatically suppressed the NF-κB promoter activity by inhibiting signaling factors involved in the MDA5/RIG-I signaling pathway. Interestingly, NS2A suppressed all components of MDA5/RIG-I signaling pathway, but NS4A inhibited most signaling molecules, except IKKε and IRF3-5D. In addition, both NS2A and NS4A downregulated MDA5-induced NF-κB promoter activity in a dosedependent manner. Taken together, our results suggest that NS2A and NS4A signifcantly antagonize MDA5/RIG-I-mediated NF-κB production, and these proteins seem to be controlled by different mechanisms. This study could help understand the mechanisms of how ZIKV controls innate immune responses and may also assist in the development of ZIKV-specific therapeutics.

• Journal of Microbiology and Biotechnology
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• v.29 no.8
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• pp.1316-1323
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• 2019

Middle East respiratory syndrome coronavirus (MERS-CoV) is a newly emerging coronavirus which is zoonotic from bats and camels. Its infection in humans can be fatal especially in patients with preexisting conditions due to smoking and chronic obstructive pulmonary disease (COPD). Among the 25 proteins encoded by MERS-CoV, 5 accessory proteins seem to be involved in viral evasion of the host immune responses. Here we report that ORF4a, ORF4b, and ORF8b proteins, alone or in combination, effectively antagonize nuclear factor kappa B ($NF-{\kappa}B$) activation. Interestingly, the inhibition of $NF-{\kappa}B$ by MERS-CoV accessory proteins was mostly at the level of pattern recognition receptors: melanoma differentiation-associated gene 5 (MDA5). ORF4a and ORF4b additively inhibit MDA5-mediated activation of $NF-{\kappa}B$ while that of retinoic acid-inducible gene 1 (RIG-I) is largely not perturbed. Of note, ORF8b was found to be a novel antagonist of MDA5-mediated $NF-{\kappa}B$ activation. In addition, ORF8b also strongly inhibits Tank-binding kinase 1 (TBK1)-mediated induction of $NF-{\kappa}B$ signaling. Taken together, MERS-CoV accessory proteins are involved in viral escape of $NF-{\kappa}B$-mediated antiviral immune responses.

• Journal of Microbiology and Biotechnology
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• v.30 no.12
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• pp.1801-1809
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• 2020

Chikungunya virus (CHIKV) was first identified in 1952 as a causative agent of outbreaks. CHIKV is transmitted by two mosquito species, Aedes aegypti and A. albopictus. Symptoms after CHIKV infection in human are typically fever and joint pain, but can also include headache, muscle pain, joint swelling, polyarthralgia, and rash. CHIKV is an enveloped single-stranded, positive-sense RNA virus with a diameter of approximately 70 nm. The pathogenesis of CHIKV infection and the mechanism by which the virus evades the innate immune system remain poorly understood. Moreover, little is known about the roles of CHIKV-encoded genes in the viral evasion of host immune responses, especially type I interferon (IFN) responses. Therefore, in the present study, we screened CHIKV-encoded genes for their regulatory effect on the activation of nuclear factor kappa B (NF-κB), a critical transcription factor for the optimal activation of IFN-β. Among others, non-structural protein 2 (nsP2) strongly inhibited melanoma differentiation-associated protein 5 (MDA5)-mediated induction of the NF-κB pathway in a dose-dependent manner. Elucidation of the detailed mechanisms of nsP2-mediated inhibition of the MDA5/RIG-I signaling pathway is anticipated to contribute to the development of virus-specific therapeutics against CHIKV infection.

• The Korea Journal of Herbology
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• v.33 no.1
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• pp.27-35
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• 2018

Objectives : Gastrodiae Rhizoma extract (GE) is possess the various bioactive compounds such as gastrodin, vanilyl alcool and p-hydroxybenzyl alcohol. Various processing methods such as steaming have been widely applied to ease ingestion and enhance the therapeutic effects of plant materials including GE in East-Asia area. The aim of this study was to evaluate the dermal bioactive properties of GE. Methods : First, total phenol, total flavonoid, gastrodin and ergothionein contents of GE were measured. In order to evaluate the dermal bioactive properties of steamed GE compared with not-steamed GE, tyrosinase, collagenase and elastase inhibitory activity were tested. Furthermore, the anti-oxidant activity of GE assessed based on DPPH and ABTS radical scavenging assay. Results : In results, total phenol and total flavonoid contents were increased when 9 times steamed compared to not-steamed GE. Also, GE increased gastrodin contents, in proportion to the number of steaming times and ergothioneine content was abolished in the steaming state. The DPPH radical scavenging activity of GE increased by steaming, but the ABTS radical scavenging activity was not related to the steaming process. In addition, the tyrosinase inhibitory activity was increased as the number of steaming times of GE increased. Collagenase was most inhibited by 4 times steamed GE, and elastase was inhibited by 8 times steamed GE. Conclusion : In conclusion, these results suggest that steamed GE extract has the potential as a cosmetic material which possess anti-oxidant and whitening activities than not steamed GE.

• Journal of the Korean Ceramic Society
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• v.56 no.2
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• pp.205-210
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• 2019

Bioactive glass (BG) finds limited use as a bone replacement material owing to its low mechanical properties. In order to solve this problem, the micro-sized 13-93 BG was prepared as a fabric composite with SiC microfibers, and its mechanical properties and biocompatibility were investigated in this study. The tensile strengths of BG-SiC fiber-bundle composites increased in proportion to the number of SiC fibers. In particular, even when only one SiC fiber was substituted, the tensile strength increased by 81% to 1428 MPa. In the early stage of the in-vitro test, a silica-rich layer was formed on the surface of the 13-93 BG fibers. With time, calcium phosphate grew on the silica-rich layer and the BG fibers were delaminated. On the other hand, no products were observed on the SiC fibers for 7 days, therefore, SiC fibers are expected to maintain their strength even after transplantation in the body.