• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.6
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• pp.602-605
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• 2000

Human alveolar bone cells were isolated from alveolar bone fragments obtained from normal individual undergoing third molar extractions. Alveolar bone fragments were cultured as explant. Cells began to migrate in the first $5{\sim}7$ day and were confluent in $5{\sim}7$ week. Matrix mineralization was observed by 4 week. Our studies utilize established protocols for the characterization of these cells as osteoblasts by means of alkaline phosphatase activity determination, identification of osteocalcin antigens, establishing the presence of cells expressing type I collagen and determining the ability of cells to produce calcification. Transmission electron microscopic observations confirmed the presence of a collagen matrix undergoing a mineralization process. This new model, using human alveolar bone cells, may provide a tool to investigate alveolar bone development and physiology and to set up new therapeutic approaches.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.6
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• pp.1332-1338
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• 1999

Intermolecular collagen cross links stabilize collagen fibrils and are necessary for normal tensile strength in collagen fibrils. Once the fibrils are aligned, hydroxyllysine, hydroxylysine derived aldehyde modified enzymatically, reacts with hydroxylysine to form the dehydrodihydroxylysinonorleucine (DHLNL), an immature crosslink. Pyridinoline, one of matured cross links is presumably formed nonenzymatically through condensation of DHLNL and hydroxylysine residue. It is widely distributed in hard connective tissues such as cartilage, bone and tendon. L ascorbic acid(AsA) is well known to be required for the enzymatic hydroxylation of proline and lysine in collagen fibrils. The purpose of this study is to clarify the role of AsA on the biosynthesis of DHLNL in vitro. We examined the effect of AsA on the formation of hydroxylysine and DHLNL in collagen. Pyridinoline and DHLNL were measured as a function of time. The contents of DHLNL was increased, reached maximum within 2 hr and was held until 24 hr, then it decreased slowly. On the contrary, pyridinoline increased gradually after 24 hr and continued to increase for 2 weeks. Moreover, the contents of DHLNL remarkably decreased at 60 min after incubation, the contents of DHLNL was decreased by addition of AsA or dehydroascorbic acid(DHA). These results suggest that the supplementation of AsA causes decrease in DHLNL formation and pyridinoline formed by nonenzymatic reaction of DHLNL.

• The Journal of the Korean dental association
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• v.55 no.10
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• pp.676-687
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• 2017

Objectives : The aim of this study was to evaluate the effects of a composite of bone substitute and collagen barrier membrane (bone patch) for local ridge augmentation at peri-implant dehiscence defects on the clinical efficacy and positional stability in dogs. Materials and methods : Implant placement and ridge augmentation procedure were performed at surgically created peri-implant dehiscence defects in canine mandible (n=6). Four treatment modalities were randomly applied: i) bone patch group, ii) Guided bone regeneration (GBR) without pin fixation group (bone graft and collagen membrane), iii) GBR with pin fixation group, and iv) negative control group. After 12 weeks, clinical, micro-CT and histological analyses were performed. Results : Histologic analysis showed that bone patch group had similar results to GBR group and GBR with fixation group in terms of new bone formation. Micro-CT analysis revealed similar results to histologic analysis in terms of total volume maintenance. Operating time was shorter in bone patch group compared to GBR group and GBR with fixation groups. Conclusions : GBR using bone patch could simplify the ridge augmentation procedure with reduced operating time and equivalent biological performance compared to the conventional procedure.

• Journal of Periodontal and Implant Science
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• v.36 no.1
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• pp.195-210
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• 2006

The aim of this study is to evaluate the effects of combination of rhBMP-4 and chitosan, which have osteoinductive capacity, on the regeneration of bone defects in dogs. Three beagle dogs aged over one and half years and weighed about 15Kg were used in this study. Three round defects were made by trephine bur in each side of mandibles. Each defect was filled with collagen, chitosan, rhBMP-4/chitosan. The dogs were sacrificed at 1, 3 or 8 weeks postsurgery and the results were evaluated histologically. The results of this study were as follows: 1. The sign of new bone formation, rearrangement of osteoblasts was revealed adjacent of preexisted bone or around graft materials such as chitosan. 2. The descending order of groups in bone regeneration speed was the rhBMP-4/chitosan group, chitosan group, collagen group. In the combination group, new bone was regenerated more and in better quality than others. 3. The regeneration of bone was observed in the rhBMP-4/chitosan group in 3 weeks after surgery. In 8 weeks after surgery, bone regeneration was observed in all three groups, and new bone at 8th week was denser in the chitosan and rhBMP-4/chitosan group than collagen group. In conclusion, rhBMP-4 and chitosan can be applied in the bone regeneration procedures usefully. It is considered that chitosan can be a splint for the maintenance of the defect form and produce much better effect when used with good grafting material or bone morphogenetic protein.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2003.11a
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• pp.79-79
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• 2003

Recently diabetes has been found to be associated with metabolic bone diseases such as osteoporosis. In the present study, attempts have been made-to explore the effect of high glucose in bone formation. Osteoblast-like UMR 106 cells were treated with high glucose (22mM, 33mM, 44mM) for 1 or 2 days. High glucose significantly inhibited proliferation of UMR106 cells in a time- and dose- dependent manner as evidenced by MTT assay. For the evaluation of collagen synthesis, UMR 106 cells were cultured in high glucose media (44mM) for 24 h and the ratio of collagen content to total protein was measured. In addition, gene expression pattern of type I collagen was assessed by RT-PCR. The high concentration of glucose inhibited a collagen synthesis, a marker of bone formation activity. JNK, c- Jun N-terminal Kinase, is known to play an important role in stress-associated cell death. In this regard, we tested to determine whether high glucose has any effect on JNK activity. It has been found that treatment of high glucose induced phosphorylation of JNK. On the other hand, ERK phosphorylation was inhibited by high glucose in a dose-dependent manner. Taken together, Therefore these results indicate that inhibition of proliferation in UMR 106 cells following high glucose is related to JNK/ERK containing signal pathways. This study showed high glucose concentration could alter the bone metabolism leading to defective bone formation, suggesting that high glucose due to diabetes may playa significant role in the development of metabolic bone disease.

• Journal of Dairy Science and Biotechnology
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• v.31 no.2
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• pp.161-164
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• 2013

The prevalence rate of osteoporosis in older men and women has recently increased, and thus bone health is a major concern in Korea. This concern, along with increasing concern regarding youth height, has led to growth of the functional food industry for children, reaching approximately 200 billion won. It is necessary to develop safe and effective functional materials for bone growth and health. Foods are excellent sources of functional material as they are safe to use. It is well known that the phosphopeptide casein, which is derived from milk, is effective against osteoporosis by aiding in the absorption of calcium. In our study, collagen peptides derived from porcine skin were evaluated as a functional material for bone growth, as several peptides have been shown to aid in osteoblast formation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.12
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• pp.1769-1775
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• 2010

Menopause is often associated with the incidence of several chronic diseases including osteoporosis, cardiovascular disease, and obesity. The purpose of this study was designed to evaluate the possibility of osteoporosis prevention in postmenopausal women. In this study, we investigated the effects of Ecklonia stolonifera (ES) extracts on bone turnover markers in ovariectomized rats. For this study, the following four groups of 9-week-old Sprague-Dawley rats were evaluated over 6 weeks: normal rats (SHAM), ovariectomized rats (OVX-CON) and ovariectomized rats that were treated with ES extracts. We measured the osteocalcin and C-telopeptide of collagen cross-links (CTx) content, enzyme ALP activity in serum and collagen content in the cartilage, bone, skin and lungs. We found that the levels of indicators of bone metabolism such as alkaline phosphatase (ALP), osteocalcin and CTx were lower in rats in the ES extract group than the OVX-CON group. In addition, the collagen contents in the bone, cartilage, skin and lungs decreased in response to ovariectomy, but the levels of collagen were greater in the bone of rats that were treated with ES extract than in the bone of rats in the OVX-CON group. These results suggest that the ES may be an effective functional food to prevent osteoporosis in postmenopausal women.

• Journal of Periodontal and Implant Science
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• v.40 no.5
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• pp.232-238
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• 2010

Purpose: To prolong the degradation time of collagen membranes, various cross-linking techniques have been developed. For cross-linking, chemicals such as formaldehyde and glutaraldehyde are added to collagen membranes, but these chemicals could adversely affect surrounding tissues. The aim of this study is to evaluate the ability of porous non-chemical cross-linking porcine-derived collagen nanofibrous membrane to enhance bone and associated tissue regeneration in one-wall intrabony defects in beagle dogs. Methods: The second and third mandibular premolars and the first molars of 2 adult beagles were extracted bilaterally and the extraction sites were allowed to heal for 10 weeks. One-wall intrabony defects were prepared bilaterally on the mesial and distal side of the fourth mandibular premolars. Among eight defects, four defects were not covered with membrane as controls and the other four defects were covered with membrane as the experimental group. The animals were sacrificed 10 weeks after surgery. Results: Wound healing was generally uneventful. For all parameters evaluating bone regeneration, the experimental group showed significantly superior results compared to the control. In new bone height (NBh), the experimental group exhibited a greater mean value than the control ($3.04{\pm}0.23\;mm/1.57{\pm}0.59$, P=0.003). Also, in new bone area (NBa) and new bone volume (NBv), the experimental group showed superior results compared to the control (NBa, $34.48{\pm}10.21%$ vs. $5.09{\pm}5.76%$, P=0.014; and NBv, $28.04{\pm}12.96$ vs. $1.55{\pm}0.57$, P=0.041). On the other hand, for parameters evaluating periodontal tissue regeneration, including junctional epithelium migration and new cementum height, there were no statistically significant differences between two groups. Conclusions: Within the limitations of this study, this collagen membrane enhanced bone regeneration at one-wall intrabony defects. On the other hand, no influence of this membrane on periodontal tissue regeneration could be ascertained in this study.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.11a
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• pp.40.2-40.2
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• 2009

Using the favorable resorption behavior of amorphous Calcium phosphate (CaP) we fabricated a gelatin basednano fibrous mat by electrospinning for using as a fast healing patch for minorbone defects. Bone is predominantly formed by an inorganic phase of nano-crystalline HAp materials and nano fibrous protein material of collagen. The osteoblast cells, which are the bone formation cells and are key to the new bone formation, receive these materials to form new bone. Taking these considerations we make a new nano fibrous mat of amorphous CaP and gelatin, which is derived from collagen itself. A polymer carrier of poly caprolactone(PCL) was used in the system to stabilize the materials in biological condition. The electrospinning conditions were optimized for smooth mat without any droplet formation. The fabricated mat was characterized for its morphologyby SEM. Mechanical properties like tensile strength was evaluated. To investigate the bio-compatibility we performed the MTT assay and investigated its resorption behavior and apatite formation behavior by SBF immersion.

• Journal of Life Science
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• v.17 no.7 s.87
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• pp.931-936
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• 2007

The aim of this study was to evaluate the effects of Codium Fragile(CF) extract on the collagen content and collagen cross-link content of the connective tissues, alkaline phosphatase activity and calcium levels of serum in ovariectomized estrogen-deficient rats. Three groups were surgically ovariectomized. The fourth group was sham operated. Sprague-Dawley female rats were randomly assigned to the following groups : sham-oper-ated rats(Sham), ovariectomized control rats (OVX-CON), ovariectomized rats supplemented with CF at 50 mg/kg body wt and 200 mg/kg body wt, respectively The CF were orally administrated at 1mLa day. The ovariectomy caused a decreasing in collagen content in bone, cartilage, skin and lung tissues. However CF groups, supplementation with Codium Fragile extract, increased in collagen contentin bone and cartilage tissues than OVX-CON group. Fyridinoline content in cartilage collagen was de-creased by ovariectomy but supplementation with the CF extracts was similarly increased to Sham. Alkaline phosphatase activity on serum of CF groups decreased than OVX-CON group. These results suggest that CF supplementation prevents post-menopausal bone loss, thus it may be used possibly to improve the quality of life in menopausal women.