• Journal of Periodontal and Implant Science
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• v.25 no.3
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• pp.623-634
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• 1995

Periodontitis is characterized by gingival inflammation and results in periodontal pocket formation with loss of the supporting alveolar bone and connective tissue around the teeth. Therapeutic modalities should therefore aim not only at eliminating the gingival inflammatory process and preventing the progression of periodontal disease but also at reestablishing and regenerating the periodontal tissue previously lost to the disease. To achieve periodontal regeneration, progenitor cells must migrate to the denuded root surface, attach to it, proliferate and mature into an organized and functional fibrous attachment apparatus. Likewise, progenitor bone cells must also migrate, proliferate, and mature in conjunction with the regenerating periodontal ligament. Significant advances have been made during the last decade in understanding the factors controlling the migration, attachment and proliferation of cells. A group of naturally occuring molecules known as polypeptide growth factors in conjunction with certain matrix proteins are key regulators of these biological events. Of these, the fibroblast growth factor(FGF), platelet-derived growth factor(PDGF) , insulin like growth factor(CIGFs), transforming growth factor(TGFs), epidermal growth factor(EGF) and bone morphogenetic growth factor(BMPs) apper to have an important role in periodontal wound healing. The purpose of this study was to determine the effects of BMP on periodontal ligament cells. Human periodontal ligament cells were cultured from extracted tooth for non-periodontal reason. Cultured periodontal ligament cells were treated with BMP. Cellular activities were determined by MTT(3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) assay and ALP(alkaline phosphatase) activity. The results were as follows ; Regardless of cultured time, cellular activities were stimulated by BMP. Also, BMP greatly increased alkaline phosphatase(ALP) in periodontal ligament cells. These results suggest that BMP not only have no cytotoxic effect on periodontal ligament cells, but also have osteogenic stimulatory effect on periodontal ligament cells.

• International Journal of Oral Biology
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• v.42 no.4
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• pp.203-211
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• 2017

The aim of this study was to evaluate the role of demineralized and particulate autogenous tooth, and interleukin-6 in bone regeneration. A demineralized and particulate autogenous tooth was prepared and human osteoblast-like cells (MG63) and human osteosarcoma cells were inoculated into the culture. The rate of cell adhesion, proliferation and mineralization were examined, and the appearance of cellular attachment was observed. An 8 mm critical size defect was created in the cranium of rabbits. Nine rabbits were divided into three groups including: An experimental group A (3 rabbits), in which a demineralised and particulate autogenous tooth was grafted; an experimental group B (3 rabbits), in which a demineralized, particulate autogenous tooth was grafted in addition to interleukin-6 (20 ng/mL); and a control group. The rabbits were sacrificed at 1, 2, 4 and 6 weeks for histopathological examination with H-E and Masson's Trichrome, and immunohistochemistry with osteocalcin. The cell-based assay showed a higher rate of cell adhesion, mineralization and cellular attachment in the experimental group A compared with the control group. The animal study revealed an increased number of osteoclasts, newly formed and mature bones in the experimental group A compared with the control group. Eventually, a higher number of osteoclasts were observed in the experimental group B. However, the emergence of newly formed and mature bone was lower than in the experimental group A. The current results suggest that treatment with demineralized and particulate autogenous tooth and interleukin-6 is not effective in stimulating bone regeneration during the bone grafting procedure.

• Korean Journal of Materials Research
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• v.20 no.6
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• pp.312-318
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• 2010

Multilayer Poly methyl methacrylate (PMMA)/ Poly vinyl alcohol (PVA) bone plates were fabricated using electrospinning and in vitro investigations were carried out for pre-clinical biocompatibility studies. The initial cellular cytotoxicity of the methacrylate (PMMA)/ Poly vinyl alcohol (PVA) bone plates was measured by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay using fibroblast-like L-929 cells. Cellular adhesion and differentiation studies were carried out using osteoblast-like MG-63 cells. As simulated body fluid (SBF) contains the same ionic concentration of body fluid and any bioactive material tends to deposit bone-like apatite on the samples surfaces into the SBF, in vitro bioactivity of the multilayer bone plates were investigated using SBF. We also studied the internal organization and tensile strength of the multilayer PMMA/PVA bone plates using micro-computed topography (${\mu}$-CT) and universal testing instrument (UTI, Korea) respectively. The cellular cytotoxicity study with MTT confirmed that the cellular viability was 78 to 90% which indicates good cyto-compatibility. Scanning electron microscopic findings revealed a good attachment and adhesion phenomenon of MG-63 cells onto the surfaces of the samples. Cellular differentiation studies also showed that osteogenic differentiation was switched on in a timely manner and affirmed along with that of the control group. Bone-like apatite formation on the surfaces was confirmed within 14 days of SBF incubation. Initial organizations of the multilayer PMMA/PVA bone plates were characterized as dense and uniform. The tensile strength of the post-pressing electronspun mat was higher than that of the pre-electronspun mat. These results suggest that a multilayer PMMA/PVA bone plate system is biocompatible, bioactive and a very good alternative bone plate system.

• Journal of Periodontal and Implant Science
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• v.25 no.3
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• pp.539-556
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• 1995

Periodontal therapeutic modalities should be re-establishing and regenerating the periodontal tissue previously lost to the disease. To achieve periodontal regeneration, periodontal ligament cells must selective migrate to the deneded root surface, attached and proliferated it. Local pH concentration is one of the most factors that periodontal regeneration. The aims of this study were to examine on biological effects of pH to the human periodontal ligament cells in vitro, especially on the cell morphology, attachment, activity, vitality and viability. Human periodontal ligament cells were cultured from extracted tooth for non-periodontal reason. Immediately after extraction, any soft tissue adhering to the cervical parts of the roots was carefully removed with a sterile curette. To produce different pH levels in the media, Eagle's MEM was adjusted from pH 6.6 to 8.2 in 0.2 intervals with 1 M NaOH and 1 N HCl. After cultivation, Then, Periodontal ligament cells were cultured at pH ranging from 6.6-8.2. attachment assay was done at 1, 2 day incubation and activity assay was done at 1, 2, 3 day incubation. The experiments were evaluated by scaning electron microscopic techniques (HITACHIX-650 Scaning Electron Microanalyzer, Tokyo, Japan), MTT assay, and the cultured periodontal ligament cells were fixed in neutral formalin for 24 hours and immunohistochemically processed by PCNA for proliferating ability. The surviving cells in the medium showed slightly increased volume and widening intercellular distances at low concentration of pH than control group (pH 7.4), and apparently shrinkage at high concentration of pH than control group (pH 7.4). The results of the statistical analysis from the experiment on attachment, vitality and viability were as follows. Attachment of periodontal ligament cells at 1st and 2nd day, similar attachment rate of low concentration pH compared with control value (pH 7.4). But above pH 8.0, attachment rate were statistically significant decrease from control value(P<0.05). Periodontal ligament cell's activities were maximum at pH 7.6 by MTT assay. Similar with control value at low concentration of pH. But, the activities were statistically significant decrease at high concentraration of pH(P<0.05). Cellular proliferating rate (PCNA index) were statistically significant decrease from control value at low and high concentration of pH(p<0.05). This results suggested that hjgh concentration pH, in other words, alkali pH was cytotoxic effects on human periodontal ligament cells in vitro.

• Carbon letters
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• v.17 no.1
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• pp.45-52
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• 2016

The attachment of 2-aminobenzamide to carboxylated multi-wall carbon nanotubes (MWCNTs)-COOH was achieved through the formation of amide bonds. Then, the functionalized MWCNTs, MWCNT-amide, were treated by phosphoryl chloride to produce MWCNT-quin. The products were characterized by Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron microscopy, thermogravimetric analysis, derivative thermogravimetric, steady-state fluorescence spectroscopy, and solubility testing. MWCNT-quin showed photo-electronic properties, which is due to the attachment of the 4-hydroxyquinazoline groups to them as proved by steady-state fluorescence spectroscopy. This suggests intramolecular interactions between the tubes and the attached 4-hydroxyquinazoline. The toxicity of the samples was evaluated in human embryonic kidney HEK293 and human breast cancer SKBR3 cell lines, and the viable cell numbers were measured by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyltetrazolium bromide (MTT) after the cells were cultured for 24 h. Cellular investigations showed that the modified MWCNTs, particularly MWCNT-quin, have considerably significant toxic impact on SKBR3 as compared to HEK293 at the concentration of 5 µg/mL.

• Fisheries and Aquatic Sciences
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• v.17 no.3
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• pp.385-390
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• 2014

Abalone immortal cell lines can be used to study the physiological properties and disease mechanisms of abalone at the cellular and molecular level. As a first step for the final goal to establish abalone immortal cell lines, we examined various initial culture conditions for primary cell populations derived from Haliotis discus hannai radula tissue. The survival rate after cell isolation procedures using the enzymatic method was as low as $9.95{\pm}2.37%$. Based on three different experimental conditions for H. discus hannai radula-derived cell culture, we found that the salinity of the media and the presence of growth-promoting factors were important to support radula-derived primary cell populations during the initial culture. The growth factor-containing media adjusted to 35 psu salinity could induce 100% (8 out of 8 trials) initial cell attachment, and the rate of cell attachment reached 50-70%. The data obtained from this study will provide useful information for developing immortal cell lines from abalone species.

• Restorative Dentistry and Endodontics
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• v.35 no.3
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• pp.222-228
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• 2010

The purpose of this study was to compare mineral trioxide aggregate (MTA; Dentsply, Tulsa Dental, Tulsa, OK, USA), which is widely used as root-end filling material, with DiaRoot BioAggregate (DB; Innovative BioCaramix Inc, Vancouver, BC, Canada), newly developed product, by using MG63 osteoblast-like cells. MTA, DB, and Intermediate Restorative Material (IRM; Dentsply Caulk, Milford, DE, USA) were used for root-end filling material while tissue culture plastic was used for control group. Each material was mixed and, the mixtures were left to set for 24 hours. MG63 cells were seeded to each group and then they were cultured for attachment for 4 hours. Following the attachment of cells to the root-end filling material, early cellular response was observed. After another 12 hours'culture, the level of attachment between cells and material was observed and in order to identify the effect of each material to bone formation, transforming growth factor beta1 ($TGF{\beta}1$) and osteocalin (OC) were estimated by using enzyme-linked immunosorbent assay (ELISA), and the amount of alkaline phosphatase (ALP) was also measured. The data were analyzed using one-way ANOVA. As a result, only at OC and the number of cells which were attached to materials, there was no statistical difference between MTA and DB. At other items, there was statistically significant difference in all groups. Although DB has not shown exactly the same cellular response like that of MTA, the number of attached cells shows that biocompatibility of the material and OC indicates bone formation rate. Therefore, if DB is used for root end filling material, it is expected to lead to similar results to MTA.

• Journal of Dental Rehabilitation and Applied Science
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• v.32 no.4
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• pp.263-273
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• 2016

In the implant prosthetic procedure, the soft tissue reaction was varied with the material and surface treatment of the abutment. It may be the cause of the peri-implantitis, and hence it can affect the long-term prognosis of the implant prosthesis. Titania and zirconia abutment presented superior biocompatibility and stable soft tissue reaction, while gold alloy abutment showed unfavorable reaction sometimes. A soft tissue reaction can be differed by the surface characteristics even in the same material type. Because rougher surface induces a bacterial attachment, the part contacting a soft tissue should have smooth surface. Additional surface treatment can enhance the cellular response without increasing bacterial attachment. Repeated removal and insertion of the abutment and the shape of the abutment may affect the soft tissue reaction, also. Ultrasonic cleaning and argon plasma cleaning are effective way to clean the retained micro-dust on the customized abutment.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.38
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• pp.17.1-17.6
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• 2016

Background: The aim of this study is to verify the feasibility of using silk fibroin (SF) as a potential membrane for guided bone regeneration (GBR). Methods: Various cellular responses (i.e., cell attachment, viability, and proliferation) of osteoblast-like MG63 cells cultured on an SF membrane were quantified. After culturing on an SF membrane for 1, 5, and 7 days, the attachment and surface morphology of MG63 cells were examined by optical and scanning electron microscopy (SEM), cell viability was determined using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and cell proliferation was quantified using 4',6-diamidino-2-phenylindole (DAPI) fluorescence staining. Results: Optical microscopy revealed that MG63 cells cultured on the SF membrane proliferated over the 7-day observation period. The viability of cells cultured on SF membranes (SF group) and on control surfaces (control group) increased over time (P < 0.05); however, at respective time points, cell viability was not significantly different between the two groups (P > 0.05). In contrast, cell proliferation was significantly higher in the SF membrane group than in the control group at 7 days (P < 0.05). Conclusions: These results suggest that silk fibroin is a biocompatible material that could be used as a suitable alternative barrier membrane for GBR.

• BMB Reports
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• v.29 no.2
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• pp.175-179
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• 1996

Viral surface proteins are known to play an essential role in attachment of the virus particle to the host cell membrane. In case of the hepatitis B virus (HBV) several reports have described potential receptors on the target cell side, but no definite receptor protein has been isolated yet. As for the viral side, it has been suggested that the preS region of the envelope protein, especially the preS1 region, is involved in binding of HBV to the host cell. In this study, preS1 region was recombinantly expressed in the form of a maltose binding protein (MBP) fusion protein and used to identify and visualize the expression of putative HBV receptor(s) on the host cell. Using laser scanned confocal microscopy and by FACS analysis, MBP-preS1 proteins were shown to bind to the human hepatoma cell line HepG2 in a receptor-ligand specific manner. The binding kinetic of MBP-preS1 to its cellular receptor was shown to be temperature and time dependent. In cells permeabilized with Triton X-100 and treated with the fusion protein, a specific staining of the nuclear membrane could be observed. To determine the precise location of the receptor binding site within the preS1 region, several short overlapping peptides from this region were synthesized and used in a competition assay. In this way the receptor binding epitope in preS1 was revealed to be amino acid residues 27 to 51, which is in agreement with previous reports. These results confirm the significance of the preS1 region in virus attachment in general, and suggest an internalization pathway mediated by direct attachment of the viral particle to the target cell membrane.