• Korean Journal of Materials Research
• /
• v.22 no.6
• /
• pp.285-291
• /
• 2012

Hydroxyapatite (HA) is well known as a biocompatible and bioactive material. HA has been practically applied as bone graft materials in a range of medical and dental fields. In this study, two types of dense hydroxyapatite ceramics were prepared from natural bones and synthetic materials. The biocompatibility of HA ceramics for supporting osteoblast cell growth and cytotoxicity using an in vitro MG-63 cell line model were respectively evaluated. Artificial hydroxyapatite shows relative density of 93% with 1-2 ${\mu}m$ after sintering, but a hydroxyapatite compact derived from bovine bone has low sintered density of 85% with a small content of MgO. Irrespective of the starting raw materials, both types of sintered hydroxyapatite displayed similar biocompatibility in the tests. FE-SEM observations showed that most MG-63 cells had a stellar shape and formed an intercellular matrix containing fibers on sintered HA. The cells were well attached and grown over the HA surface, indicating that there was no toxicity.

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

• Journal of Microbiology and Biotechnology
• /
• v.28 no.3
• /
• pp.381-390
• /
• 2018

We have previously derived a novel antimicrobial peptide, LPcin-YK3(YK3), based on lactophoricin and have successfully studied and reported on the relationship between its structure and function. In this study, antimicrobial peptides with improved antimicrobial activity, less cytotoxicity, and shorter length were devised and characterized on the basis of YK3, and named YK5, YK8, and YK11. The peptide design was based on a variety of knowledge, and a total of nine analog peptides consisted of one to three amino acid substitutions and C-terminal deletions. In detail, tryptophan substitution improved the membrane perturbation, lysine substitution increased the net charge, and excessive amphipathicity decreased. The analog peptides were examined for structural characteristics through spectroscopic analytical techniques, and antimicrobial susceptibility tests were used to confirm their activity and safety. We expect that these studies will provide a platform for systematic engineering of new antibiotic peptides and generate libraries of various antibiotic peptides.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2011.05a
• /
• pp.51.1-51.1
• /
• 2011

An electrospun Poly (lactice-co-glycolide acid) (PLGA) and Gelatin nanofiber tube was fabricated for potential intestinal stent application. Mechanical properties of tube were evaluated by tensile strength and burst strength tests. Physical and chemical properties were evaluated by contact angle measurement, swelling rates and porosity measurements. Biodegradability was investigated by immersion in simulated body fluid (SBF). Biocompatibility was investigated in vitro by cytotoxicity and proliferation studies by MTT assay, confocal microscopy and western blot using IEC-18 (Rat intestinal epithelial cell). After intestinal stent was implanted into rat bowel for periods from 7 to 10days, it was then analyzed using micro-computed tomography (Micro CT) and X-ray techniques. Futhermore, histological analysis was performed by hematoxylin-eosin (H&E) stain.

• Food Science and Biotechnology
• /
• v.15 no.2
• /
• pp.312-316
• /
• 2006

Crude extract of young dangyuja (Citrus grandis Osbeck) fruit was investigated for its antioxidant activity as measured by 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity. Among the samples, including 4 Citrus species and various solvent-extracted-fractions of young dangyuja fruit, the water-extracted fraction (WF) and butanol-extracted fraction (BF) showed the greatest DPPH free radical scavenging activity. WF and BF were further examined for their antioxidant activities by three different in vitro assays. The cell viability tests using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction assay showed that both fractions significantly reduced $H_2O_2$-induced cytotoxicity in HepG2 cells dose-dependently. Generation of the reactive oxygen species (ROS) was also reduced in cells pretreated with both fractions. In addition, BF showed a higher level of lipid peroxidation inhibitory capacity than WF in $H_2O_2$-treated HepG2 cells. Taken together, these results indicate that young dangyuja fruit can be used as an easily accessible source of natural antioxidants.

• Biomolecules & Therapeutics
• /
• v.14 no.3
• /
• pp.148-151
• /
• 2006

We have previously reported that 2.4 kb of L-plastin promoter (LP) could regulate the expression of adenoviral vector (AV) exogenous genes in a tumor cell specific manner. In the present study, we tested if the replication competent AdLPE1A vector results in a direct cytotoxic effect in hepatocelluar carcinoma (HCC) cells. In vitro cytotoxicity tests were carried out with replication-competent (AdLPE1A) and -incompetent (AdLPCD) LP-driven vectors. AdLPE1A is an AV in which LP was inserted 5' to the E1A and E1B genes. The AdLPCD vector contains LP and the E. coli cytosine deaminase (CD) gene in transcription unit. Exposure of cells to AdLPE1A generated a significant cytotoxic effect as compared to the control. Almost 90% of the cell had manifested the characteristic cytopatic effect on day 9 after infection of cells with 10 MOI of AdLPE1A. On the other hand, almost 35% of the cells were left when the cells had been treated with 100 MOI of AdLPCD together with 5-FC on day 9 when compared with the cells which had never been exposed neither 5-FC nor AdLPCD. These results showed that the replication competent AdLPE1A vector could kill the HepG2 cells directly by the oncolytic effect of the virus. The replication competent AV vector carrying viral E1A generated greater cytotoxic effect than the replication incompetent AV, which contains the CD prodrug activation transcription unit without E1A, in HepG2 cells.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.22 no.2
• /
• pp.70-75
• /
• 1996

DMHF (2.5-dimethyl-4-hydroxy-3[2H]-furanone), an antioxidative compound from the reaction of L-cysteine/D-glucose scavenged efficiently 1,1-diphenyl-2-picryl hydrazyl free radicals. It exhibited an inhibitory effect on the autoxidation of linolenic acid, and the protective effect against UV cytotoxicity in cultured human fibroblast. In addition, DMHF appeared to prevent the cellular melanogenesis in the cultured murine melanoma cells more effectively than kojic acid, a well known inhibitor of melanogenesis, while the former was not so effective as the latter for the inhibition of the tyrosinase. Considering that cellular melanogenesis is a metabolic process triggered by oxidative stress, it ovas tentatively deduced that the antioxidative property of DMHF might afford the effect against cellular pigmentation by alleviating the causative stress. In toxicological tests such as irritation and sensitization, this compound turned out to be safe. The results of this study suggest that DMHF may be a novel inhibitor of melanogenesis, and that night be useful for application in cosmetics.

• Natural Product Sciences
• /
• v.13 no.4
• /
• pp.347-354
• /
• 2007

In this study, we investigated the potential of Resina Pini (RP) for anti-inflammatory and analgesic agents to treat inflammatory diseases such as gingivitis and periodontitis. Crude RP (RP1), recrystallized RP (RP2), and Ramus Mori Albae-treated RP (RP3), plus their respective water extracts (RP1-WE, RP2-WE and RP3-WE) were prepared for in vitro and in vivo tests. We couldn't find any signs of heavy metals pollution in all the RP samples. RP2-WE exhibited the highest viability of human gingival fibroblasts (HGF) and the strongest scavenging activity on superoxide anion. RP1, RP2 and RP3, RP2 showed potent scavenging activity on DPPH free radical. RP2-WE displayed a stronger inhibition on hyaluronidase (HAase) activity and RP3 also displayed potent HAase inhibition. RP2-WE, RP3-WE, RP3 and RP2 were reduced admirably the production of $PGE_2$ in HGF. In addition, RP2-WE and RP3-WE exhibited potent inhibitory activities on arachidonic acid-induced ear edema in mouse. Moreover, RP-2 prevented completely acetic acid-induced writhing by 100.0% and RP1, RP3, RP1-WE and RP2-WE also exhibited excellent protective activities against writhing. While aminopyrine, the positive control, showed 76.9% analgesic effect at the same dose. Taken together, these results suggest that recrystallized aqueous extract of Resina Pini could be a promising drug for the treatment of periodontal diseases.

• CELLMED
• /
• v.13 no.2
• /
• pp.2.1-2.9
• /
• 2023

CPS219, a new concept compound composed of coffee (CO), Pueraria Tomsonii flower (PF), and Sambou bamboo salt^TM (BS), was developed as a coffee beverage to alleviate menopausal symptoms. The purpose of this study is to evaluate the anti-oxidant and menopausal alleviating effects of CPS219 combined as the optimal ratio of each component selected through sensory evaluation and blind consumer test. For CPS219, the optimal ratio of CO, PF, and BS was determined to be 1:0.1:0.017 through various sensory evaluations and blind consumer tests. CPS219 significantly enhanced the superoxide dismutase-like activity compared to the CO or CO plus PF (CP). The proliferation of MCF-7 cells was considerably increased after 24 hours by treatment with CO, CP, or CPS219, but only CPS219 significantly boosted the proliferation of MCF-7 cells after 48 hours. Moreover, CPS219 had an estrogen-like effect by dramatically increasing the expression of estrogen receptor-β mRNA in MCF-7 cells but not CO and CP. Treatment of MCF-7 cells with CO, CP, or CPS219 did not cause any cytotoxicity. In conclusion, these findings imply that anti-oxidant and estrogen-like properties of CPS219 can be used to prevent and cure postmenopausal symptoms.

• The Journal of Korean Academy of Prosthodontics
• /
• v.37 no.6
• /
• pp.741-755
• /
• 1999

As a material of metal-ceramic prosthesis, nickel as a form of Ni-Cr alloy has been used for many dental prostheses in many cases. However, several problems in use of the alloy have been revealed (ex : tissue stimulation, skin allergy, hypersensitivity, cytotoxicity and carcinogenecity). Little is known about nickel with respect to the relationship between Ni-prosthesis and gaining of Ni-resistance in oral microorganisms. The present study was undertaken to check wheather use of Ni-prosthesis leads to occurrence of Ni-resistant microorganisms. So this study may suggest the possible relationships between the oral microorganisms and nickel-resistance in oral environment. Bacteria were isolated from the gingival crevicular fluid on the pateints wearing Ni-Cr prosthesis. The isolated bacteria were tested for their Ni-resistance in nickel containing media at different concentration from 3mM to 110mM. E. coli HB101 was used as control. The Ni-resistant bacteria were isolated and biochemically identified. The Ni-resistant bacteria were tested several bio-chemical, molecular-biological tests. Performed tests were ; measuring the growth curve, antibiotic test, growth ability test in liquid media, isolation of the chromosome and plasmid, digestion of DNA by restriction enzyme, electrophoresis of chromosome and plasmid DNA, identification of Ni-resistant genes by the DNA hybridization. The results were as follows: 1) The bacteria isolated from gingival crevicular fluid on the patients wearing Ni-Cr alloy pros-thesis showed nickel-resistance. 2) The isolated microorganisms grew at nickel containing media of high concentrations (60mM-110mM). 3) Based on the biochemical tests, the isolated microorganisms were identified as Enterococcus faecalis(13 cases), Klebsiella pneumoniae(1 case) and Enterobacter gergeviae(1 case). 4) Enterococcus faecalis expressed not only nickel resistance but also the multi-drug resistance to several antibiotics ; chloramphenicol, kanamicin, streptomycin, lincomycin, clindamycin. However, all strain showed the sensitivity against the tetracycline. 5) DNA hybridization result suggest that there is no homology between the previousely known gene of nickel resistance in Klebsiella pneumoniae and chromosomal DNA of Enterococcus faecalis.