• Restorative Dentistry and Endodontics
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• v.20 no.2
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• pp.538-548
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• 1995

Calcium hydroxide has been used not only as pulp capping and pulpotomy agents in the operative dentistry, but dressing and temporary filling materials in root canal treatment. Calcium hydroxide was known to stimulate odontoblast to produce new reparative dentin and to eliminate microorganims effectively in the infected root canals. The purpose of this study was to evaluate the effect of calcium hydroxide solution on cultured L929 cells and its antibacterial effect on several streptococci. Calcium hydroxide solution (0.121g/100ml) was added to L929 cells and cell viability was measured using 3-(4,5-dimethylthiazol-2-yl) -2,5-dimethyltetrazolium bromide (MTT) and neutral red (NR) dye. Calcium hydroxide solution (20, 40, 60, 80, 100 and $150{\mu}l$) was added to L929 cells in 96-well microplates for 1, 4 and 24 hours respectively. Cell viability was gradually decreased when the volume and exposure time of calcium hydroxide solution were increased. When $150{\mu}l$ of calcium hydroxide was applied to L929 cells for 24 hours, there was more than fifty percent reduction of cell viability. Calcium hydroxide solution (20g/100ml) showed antibacterial effect against S. uberis, S. intermedius and S. mitis after thirty-second exposure. But 0.121g/100ml concentration of cacium hydroxide solution exhibited no antibacterial effect on six streptococci after one-hour exposure.

• Restorative Dentistry and Endodontics
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• v.17 no.1
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• pp.134-140
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• 1992

The purpose of this study was to investigate the antibacterial effect of zinc oxide eugenol(ZOE), zinc phosphate cement(ZPC), glass ionomer cement, resin, and Vitapex to S. muntans, S. sanguis, S. fecalis and E. coli by agar diffusion method. Four wells were punctured in mitis-salivarius agar plate per each group and each wells were filled with restorative matetials. The width of inhibition zones produced in mitis - salivarius agar were measured as the parameter of the antibacterial effect after 16 hours and 40 hours. In S. mutans and S. sanguis, the largest inhibition zone was produced on ZOE, followed by glass ionomer cement, and ZPC. Inhibition zones was not observed in resin and Vitapex. In S. fecalis, ZOE and glass ionomer cement showed wider inhibition zone than ZPC. In E. coli, ZOE showed wider inhibition zone than ZPC, but no inhibition zone was observed on glass ionomer cement.

• Journal of Microbiology and Biotechnology
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• v.31 no.9
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• pp.1288-1294
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• 2021

There are a growing number of reports of hospital-acquired infections caused by pathogenic bacteria, especially methicillin-resistant Staphylococcus aureus (MRSA). Many plant products are now being used as a natural means of exploring antimicrobial agents against different types of human pathogenic bacteria. In this research, we sought to isolate and identify an active molecule from Sedum takesimense that has possible antibacterial activity against various clinical isolates of MRSA. NMR analysis revealed that the structure of the HPLC-purified compound was 1,2,4,6-tetra-O-galloyl-glucose. The minimum inhibitory concentration (MIC) of different extract fractions against numerous pathogenic bacteria was determined, and the actively purified compound has potent antibacterial activity against multidrug-resistant pathogenic bacteria, i.e., MRSA and its clinical isolates. In addition, the combination of the active compound and β-lactam antibiotics (e.g., oxacillin) demonstrated synergistic action against MRSA, with a fractional inhibitory concentration (FIC) index of 0.281. The current research revealed an alternative approach to combating pathogenesis caused by multi-drug resistant bacteria using plant materials. Furthermore, using a combination approach in which the active plant-derived compound is combined with antibiotics has proved to be a successful way of destroying pathogens synergistically.

• Bulletin of the Korean Chemical Society
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• v.35 no.9
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• pp.2818-2824
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• 2014

Trp residue is considered as one of the important constituents in antimicrobial peptides (AMPs) as it presence secured good activities in many cases. However, it is preferable to be changed because of their sensitivity towards light. We have synthesized the short Trp-rich AMP Pac-525 and its analogues to investigate the possibility of His(chx) as possible replacement analogue for Trp in AMPs. Based on the assay result of the antibacterial activity including anti-MRSA activity, His(chx) is considered as good candidate for the Trp replacement. Through these study, we found that His(chx) had several merits to design therapeutic antimicrobial agents compare to Trp in terms of i) increasing antibacterial activity without hemolytic activity, ii) successful in designing the short peptide (only four residues), iii) having anti-MRSA activity, iv) overcoming the light sensitivity. Furthermore, transmission electron microscopy (TEM) and dye leakage experiments suggested that P11 and P16 containing His(chx) kill bacteria via forming pore/ion channels on bacterial cell membranes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.4
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• pp.364-370
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• 1987

A lysozyme is isolated and purified partially form the egg white of Korean native Ogol fowl(Natural monument No. 265) by the method of direct crystallization. The bacteriolytic activities of 1% lysozyme against Staphylococus aureus 57, Bacillus subtilis ATCC 6633, and Escherichia coli NIHJ-JC2 was investigated with or without some other antibacterial materials in the nutrient broth culture. According to the results, 1% lysozyme showed the appreciable bacterolytic activities of about 12-16% to the almost of bacteria cultured. The synergistic effect with the lysozyme and some antibacterial materials on the growth inhibition of the bacteria cultured exhibited higher in order of the 0.001% magnolol -22%, the 0.001% honokiol -14% against S. aureus and of the 0.0005% erythromcin -29%, the honokiol -22%, the magnolol -l7%, the 0.005% phospholipase -6% against E. coli. And that synergistic effect against B. subtilis showed a fairly high level of about 52% with the erythromycin but not any effect with others.

• Journal of Powder Materials
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• v.9 no.6
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• pp.409-415
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• 2002

In this review the methods for production and processing of isolated or agglomerated nanoscale metal particles embedded in organic liquids (nanosuspensions) and polymer matrix composites are elucidated. Emphasis is laid on the techniques of inert gas condensation (IGC) and high pressure sputtering for obtaining highly porous metal powders ("nanopowder") as well as on vacuum evaporation on running liquids for obtaining nanosuspensions. Functional properties and post-processing are outlined in view of applications in the fields of electrically conductive adhesives and anti-microbially active materials for medical articles and consumer goods.mer goods.

• Proceedings of the Materials Research Society of Korea Conference
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• 2000.11a
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• pp.149-149
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• 2000

• Bulletin of the Korean Chemical Society
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• v.24 no.5
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• pp.623-626
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• 2003

Nematophin and its analog incorporating tryptamine unit have been isolated and characterized from strain XRPC of a symbiotic bacterium Xenorhabdus nematophilus, which was newly isolated from Korean entomopathogenic nematodes. The stereoselective synthesis of these compounds was accomplished, and the relative configurations were determined. Nematophin exhibited potent antibacterial activities over several strains of methicillin-resistant S. aureus (MRSA) comparable to those of vancomycin.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.39 no.2
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• pp.43-54
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• 2013

In an attempt to regain function and aesthetics in the craniofacial region, different biomaterials, including titanium, hydroxyapatite, biodegradable polymers and composites, have been widely used as a result of the loss of craniofacial bone. Although these materials presented favorable success rates, osseointegration and antibacterial properties are often hard to achieve. Although bone-implant interactions are highly dependent on the implant's surface characteristics, infections following traumatic craniofacial injuries are common. As such, poor osseointegration and infections are two of the many causes of implant failure. Further, as increasingly complex dental repairs are attempted, the likelihood of infection in these implants has also been on the rise. For these reasons, the treatment of craniofacial bone defects and dental repairs for long-term success remains a challenge. Various approaches to reduce the rate of infection and improve osseointegration have been investigated. Furthermore, recent and planned tissue engineering developments are aimed at improving the implants' physical and biological properties by improving their surfaces in order to develop craniofacial bone substitutes that will restore, maintain and improve tissue function. In this review, the commonly used biomaterials for craniofacial bone restoration and dental repair, as well as surface modification techniques, antibacterial surfaces and coatings are discussed.

• Molecular & Cellular Toxicology
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• v.5 no.1
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• pp.23-31
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• 2009

To compare the effects of nanometer-sized silver ions and support materials (nano-silver coating material, NM-silver) and silver ions, we exposed zebrafish embryos to both types of nano-silver ions and compared the acute responses during embryogenesis. The amount of silver in the NM-silver (17.16%) was greater than that in the silver ion (4.56%). Both of these materials have different atomic compositions. The silver ion-exposed groups (10 and 20 ppt) showed lower survival rates than the NM-silver-exposed groups (10 and 20 ppt). NM-silver penetrated the skin and blood tube of zebrafish larvae as aggregated particles, whereas, silver ions penetrated the organelles, nucleus and yolk in a spread-out pattern. Micro-array analysis of RNA from zebrafish larvae (72 hours post-fertilization) that were treated with either NM-silver or silver ions, showed alteration in expression of the BMP, activin, TGF-$\beta$, and $GSK3{\beta}$ genes pathway. Additionally, $GSK3{\beta}$ gene pathway for apoptosis that was related with left-right asymmetry. Gene expression changes in the NM-silver or silver ions-treated zebrafish embryo led to phenotypic changes in the hatched larvae, reflecting increased apoptosis and incomplete formation of an axis.