• Journal of the Korean Crystal Growth and Crystal Technology
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• v.15 no.4
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• pp.152-156
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• 2005

The cultivation of akoya pearls was carried out with bio bead nucleus prepared using the hydroxyapatite. The akoya pearls cultured with bio bead nucleus were shown the color of cream. The luster and orient effect created by an action of the light from nacre were magnificent. The result of XRD is found that the nacre is a calcium carbonate of aragonite form. From the result of SEM, it is found that layers of calcium carbonate and conchiolin are stratified. The properties of akoya pearls cultured with bio bead nucleus are same those of akoya pearl cultivated with bead nucleus made from washboard shell. Because of the bio bead nucleus developed in this study has such a high capacity in producing various sizes and shapes, it is very advantageous for the cultivation of akoya pearls.

• Korean Journal of Microbiology
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• v.27 no.1
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• pp.48-55
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• 1989

The purpose of the present investigation was to improve several procedures being used in the adherence assay of Streptococcus sanguis cells to hydroxyapatite (HA) beads and to study the effect of the beads on the counting of radioactivity. The standard adhere assay involved the adherence of radiolabeled bacteria to 40mg of HA beads. The beads were mixed with ['H]thymidine-labeled bacterial cells and incubated for 60 minutes at room temperature. Unadsorbed cells were removed, the beads with adsorbed cells were dried, and the radioactivity was monitered in a scintillation spectrometer. The 30 seconds sonication of cells in a form of long chains appeared to be adequate for obtaining mostly singlet or doublet cells. Unlike the counting of S. sanguis cell suspension, bacterial cells adhered to HA or saliva-coated HA(SHA) required smaller volume (2.5ml) of scintillaton fluid for better counting. Eighteen percent quenching of counts could be attributed to the beads. Among 3 procedures commonly used to equilibrate the beads for adherence assay, no differences were found in their effectiveness. The HA beads on which the bacteria remained attached in scintillant during the counting were found to be the source of sample self-absorption representing 34.5% of the total radioactivity counts resulting from the beads dissolved in HCl solution.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.586-589
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• 2001

In this study, phosphate was produced through the solublization of hydroxyapatite and rock phosphate by Pantoea agglomerans, and it was examined the possibility of solublizing insoluble phosphate salt by immobilized P. agglomerans on Ca-alginate bead as support. 520mg/L of phosphate was solublized when P. agglomerans was cultured in HY meclium at $30^{\circ}C$, pH7, 100rpm, during 48hours culture. And solublized phosphate amount was 86.09mg/L when hydroxyapatite in the HY medium was exchanged to rock phosphate. In case of being used immobilized P. agglomerans. 740mg/L of phosphate was solublized in the HY medium, during 120hrs in the same condition. And 182mg/L of phosphate was solublized when rock phosphate was added instead of hydroxyapatite.

• Journal of Oral Medicine and Pain
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• v.33 no.3
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• pp.229-240
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• 2008

Animal mucins have structural characteristics similar to human salivary mucins. Animal mucins have been regarded as suitable substances for saliva substitutes. Since animal mucin molecules in saliva substitutes and host-derived antimicrobial salivary molecules exist simultaneously in whole saliva and the pellicles of patients with dry mouth, interactions may occur between these molecules. The purpose of this study was to investigate the influence of animal mucins on peroxidase activity in solution and on the surface of hydroxyapatite(HA) surfaces. The effects of animal mucins on peroxidase activity were examined by incubating porcine gastric mucin(PGM) or bovine submaxillary mucin (BSM) with either bovine lactoperoxidase(bLPO) or saliva samples. For solid-phase assays, immobilized animal mucins or peroxidase on three different HA surfaces(HA beads, HA disc, and bovine tooth) were used. Peroxidase activity was determined with an NbsSCN assay. The obtained results were as follows: 1. PGM enhanced the enzymatic activity of bLPO in solution phase. PGM did not affect the enzymatic activity of peroxidase in saliva sample(POS). 2. BSM did not affect the enzymatic activities of both bLPO and POS in solution phase. 3. HA-adsorbed PGM increased subsequent bLPO adsorption in all three HA phases. The activity of POS was increased on both the HA beads and bovine tooth. 4. The peroxidase activities on the HA beads and disc were increased when the HA surfaces were exposed to a mixture of bLPO and PGM. 5. The binding affinity of bLPO to PGM was greater than that of bLPO to BSM. Collectively, our results suggest that animal mucins affects the enzymatic activity of peroxidase on the HA surfaces as well as in solution. Saliva substitutes containing animal mucins may affect the function of antimicrobial components in natural saliva and saliva substitutes.

• Tissue Engineering and Regenerative Medicine
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• v.15 no.6
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• pp.735-750
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• 2018

BACKGROUND: The major challenge of tissue engineering is to develop constructions with suitable properties which would mimic the natural extracellular matrix to induce the proliferation and differentiation of cells. Poly(${\varepsilon}$-caprolactone)-poly(ethylene glycol)-poly(${\varepsilon}$-caprolactone) (PCL-PEG-PCL, PCEC), chitosan (CS), nano-silica ($n-SiO_2$) and nano-hydroxyapatite (n-HA) are biomaterials successfully applied for the preparation of 3D structures appropriate for tissue engineering. METHODS: We evaluated the effect of n-HA and $n-SiO_2$ incorporated PCEC-CS nanofibers on physical properties and osteogenic differentiation of human dental pulp stem cells (hDPSCs). Fourier transform infrared spectroscopy, field emission scanning electron microscope, transmission electron microscope, thermogravimetric analysis, contact angle and mechanical test were applied to evaluate the physicochemical properties of nanofibers. Cell adhesion and proliferation of hDPSCs and their osteoblastic differentiation on nanofibers were assessed using MTT assay, DAPI staining, alizarin red S staining, and QRT-PCR assay. RESULTS: All the samples demonstrated bead-less morphologies with an average diameter in the range of 190-260 nm. The mechanical test studies showed that scaffolds incorporated with n-HA had a higher tensile strength than ones incorporated with $n-SiO_2$. While the hydrophilicity of $n-SiO_2$ incorporated PCEC-CS nanofibers was higher than that of samples enriched with n-HA. Cell adhesion and proliferation studies showed that n-HA incorporated nanofibers were slightly superior to $n-SiO_2$ incorporated ones. Alizarin red S staining and QRT-PCR analysis confirmed the osteogenic differentiation of hDPSCs on PCEC-CS nanofibers incorporated with n-HA and $n-SiO_2$. CONCLUSION: Compared to other groups, PCEC-CS nanofibers incorporated with 15 wt% n-HA were able to support more cell adhesion and differentiation, thus are better candidates for bone tissue engineering applications.

• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.4
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• pp.691-703
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• 1998

Saliva is obviously potential medium to protect the dental caries by not only physical clearing effect, but aggregating action of protein with bacteria. Nevertheless, we still do not understand how the dental caries occur and what brings the individual difference in caries prevalence. In the regards of dental caries prevalence, we hypothesized that the composition of salivary protein might be different from caries susceptible group to caries resistant group. The purposes of this experiment were focused on the molecular analysis of salivary proteins from the subjects who were involved in multiple caries. Electrophoretic analysis was done on the whole saliva collected from the children with and without multiple caries. We found 86.2% of subjects with multiple caries has approximately 120 KDa protein band while 30.4% in the healthy subjects. And the concentration of the total protein on the subjects with multiple caries is significantly higher than that of the healthy group. However, it turned out that the difference of the salivary composition does not affect the bacterial adhesion to hydroxyapatite bead. With regards of enzymes in saliva, the activity of ${\alpha}-amylase$ and lactate dehydrogenase does not have any significant difference between both groups. However, the concentrations of $Na^+\;and\;Cl^-$ in saliva from multiple caries group is higher than that of the control group. Taken all together, it may be concluded that 120 KDa protein in saliva may be associated with the process of dental caries, also the high concentration of protein and $Na^+,\;Cl^-$ in saliva may be linked to dental caries development as a cofactors.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.3
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• pp.666-671
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• 2003

Dental caries are the most commonly occurring chronic diseases in the dental field. Because of increasing sugar consumption and extension of average human life, these diseases are widely found all over the world as the most typical cause for a person to lose a tooth. Therefore, the development of more effective, substantial and safe preventive agents against dental caries is strongly required. Streptococcus mutans is known as the causative bacterial playing the most important role informing plaque and it is being noticed as major causative bacteria of dental caries. The present study was designed to investigate the effect of Asarum sieboldii Miquel(Aristolochiaceae) extracts on the growth, acid production, adhesion, and insoluble glucan synthesis of Streptococcus mutans(S. mutans). Both methanol and aqueous extracts showed concentration dependent inhibitory activity against the growth and acid production of S. mutans, and produced significant inhibition at the concentration of 100, 1,000 and 2,000 μg/ml compared to the control group(p<0.05 - p<0.01). The extracts markedly inhibited S. mutans adherence to HA treated with saliva, and cell adherence was repressed by more than 50% at the concentration of 10 μg/ml and complete inhibition was observed at the concentration of 2,000 μg/ml. On the activity of glucosyltransferase which synthesizes water insoluble glucan from sucrose, methanol and aqueous extracts showed more than 70% inhibition over the concentration of 1,000 μg/ml. Hence, we conclude that Asarum sieboldii might be a candidate of anticaries agent.