• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제34권6호
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• pp.616-621
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• 2008

Osseointegration is a result of bone formation and bone regeneration processes, which takes place at the interface between bone and implant, and it indicates a rigid fixation that can be stably maintained while functional loading is applied inside the oral cavity as well as after implant placement. Although many researches were carried out about osseointegration mechanism, but cellular and molecular events have not been clarified. With recent development of molecular biology, some researches have examined biological determinants, such as cytokine, growth factors, bone matrix proteins, during osseointegration between bone and implant surface, other researches attempted to study the ways to increase bone formation by adhering protein to implant surface or by inserting growth factors during implant placement. Cellular research on the reaction of osteoblast especially to surface morphology (e.g. increased roughness) has been carried out and found that the surface roughness of titanium implant affects the growth of osteoblast, cytokine formation and mineralization. While molecular biological research in dental implant is burgeoning. Yet, its results are insignificant. We have been studying the roles of growth factors during osseointegration, comparing different manifestations of growth factors by studying the effect of osseointegration that varied by implant surface. Of many growth factors, $TGF-{\beta}$, IGF-I, BMP2, and BMP4, which plays a significant role in bone formation, were selected, and examined if these growth factors are manifested during osseointegration. The purpose of this article is to present result of our researches and encourage molecular researches in dental implant.

• Journal of Periodontal and Implant Science
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• 제33권4호
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• pp.573-584
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• 2003

Bone remodeling results from the combined process of bone resorption and new bone formation which is regulated in part by some of Dexamethasone related proliferation & mineralization of cultured bone cell and polypeptide growth factors such as platelet derived growth factor(PDGF), which has been known to be an important local regulator of bone cell activity and participate in normal bone remodeling. To evaluate the effects of Dex and PDGF on bony healing of calvarial defect in rats, 10 ng/ml PDGF were applied on P group and 10 ng/ml PDGF and $10^7$ M Dex were applied PD group. 4 rats in each group were sacrificed at 7, 14. 21 days after operation respectively, and the tissue blocks were prepared for light microscope with H-E for evaluation of overall healing, with TRAP(tartrate resistant acid phosphatase) for evaluation of osteoclastic activity and with immunohistochemical staining for macrophages. The results were as follows : 1. In all group, healing aspects were progressed from 7 days to 21 days in soft and bony tissue, but complete repair were not observed in bony defect 2. PDGF and control group were showed similar bony healing aspect , but bony healing in combination of PDGF-BB and Dex were observed slower aspect compared to PDGF and control group from early healing times. 3. There were no significant difference on activities of osteoclast and macrophages in bony healing between control and experimental group In conclusion, PDGF were not influenced on bony healing of defect and combination of PDGF-BB and Dex were showed slower healing through early healing times. it was considered that Dex compared to PDGF did influenced on early hone formation factors in healing period

• 대한치과보철학회지
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• 제45권1호
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• pp.107-118
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• 2007

Statement of problem: Implant-type distractor uses a removable distraction device that has an appearance similar to that of a dental implant and utilizes many of the same techniques for placement as are used for dental implants. Material and method: In this study, 48 implant type titanium distractors were inserted into the osteotomized alveolar bone of 12 beagle dogs. After a 7-day latency period, the alveolar bone was augmented by 5mm vertically at a rate of 1.0 mm/day. The dogs were sacrificed after 4weeks, 8weeks and 12 weeks for radiographic, histologic, and histomorphometric analysis. Result: Copper equivalent value showed significant difference between 4 weeks and the other weeks(8, 12 weeks)(p<0.05). But there was no significant difference between maxillary and mandibular groups. In the bone to metal contact analysis, there was a significant difference between 4 weeks and 12 weeks(p<0.05). On the contrary, there was no significant difference between maxilla and mandible. The bone area showed significantly higher values in 12 weeks compared to 4 weeks(p<0.05). Histologically mineralization began at the host bone margins. At 12 weeks, increasing accumulation of $Ca^{++}$ element was confirmed. Conclusion: From the results above, the new bone formation was increased according to consolidation period. Especially there was significant difference between 4 weeks and 12 weeks(p<0.05). Implant type distractors used in this study to augment vertical ridge defect may prove to be a clinically useful treatment option in selected cases.

• Macromolecular Research
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• 제14권5호
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• pp.565-572
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• 2006

Recombinant human bone morphogenic protein-2 (rhBMP-2), which is known as one of the major local stimuli for osteogenic differentiation, was immobilized on the surface of hyaluronic acid (HA)-modified poly$(\varepsilon-caprolactone)$ (PCL) (HA-PCL) scaffolds to improve the attachment, proliferation, and differentiation of human bone marrow stem cells (hBMSCs) for bone tissue engineering. The rhBMP-2 proteins were directly immobilized onto the HA-modified PCL scaffolds by the chemical grafting the amine groups of proteins to carboxylic acid groups of HA. The amount of covalently bounded rhBMP-2 was measured to 1.6 pg/mg (rhBMP/HA-PCL scaffold) by using a sandwich enzyme-linked immunosorbant assay. The rhBMP-2 immobilized HA-modified-PCL scaffold exhibited the good colonization, by the newly differentiated osteoblasts, with a statistically significant increase of the rhBMP-2 release and alkaline phosphatase activity as compared with the control groups both PCL and HA-PCL scaffolds. We also found enhanced mineralization and elevated osteocalcin detection for the rhBMP-2 immobilized HA-PCL scaffolds, in vitro.

• International Journal of Oral Biology
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• 제39권3호
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• pp.145-151
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• 2014

During bone remodeling, there is requirement of differentiation of osteoblastic cells. Previously, we identified proteins differentially expressed in soft tissue during bone healing. Of these proteins, we focused the effect of LTF on differentiation of osteoblast. In order to analyze the osteogenic ability of LTF, we treated conditioned media collected from human LTF-stably transfected HEK293T cells into osteoblastic MC3T3-E1. The results showed that the activity and expression of alkaline phosphatase were increased in MC3T3-E1 cells treated with conditioned media containing LTF in dose- and time-dependent manner. At the same time, we observed the significant increase of the expression of osteoblastic genes, such as ALP, BSP, COL1A1, and OCN, and along with matrix mineralization genes, such as DMP1 and DMP2, in LTF conditioned media-treated groups. Moreover, the result of treating recombinant human LTF directly into osteoblastic MC3T3-E1 showed the same pattern of treating conditioned media containing LTF. Our study demonstrated that LTF constitutively enhances osteoblastic differentiation via induction of osteoblastic genes and activation of matrix mineralization in MC3T3-E1 cells.

• 한국재료학회지
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• 제17권12호
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• pp.669-675
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• 2007

Hydroxyapatite (HAp) and biphasic calcium phosphate (BCP) nano powders were synthesized using the microwave-assisted synthesis process dependent on pH and microwave irradiation time. The average size of a powder was less than 100 nm in diameter. Through in-vitro cytotoxicity tests by an extract dilution method, the HAp and BCP nano powders have shown to be cytocompatible for L-929 fibroblast cells, osteoblastlike MG-63 cells and osteoclast-like Raw 264.7 cells. The activation of osteoblast was estimated by alkaline phosphatase (ALP) activity. When the HAp and BCP were treated to MG-63 cells, alkaline phosphatase activities increased on day 3, compared with those of the untreated cells. Also, the collagen fibers increased when the HAp and BCP powders suspension were treated to MG-63 cells, compared to those of the untreated cells. Quantitative alizarin red S mineralization assays showed a trend toward increasing mineralization in osteoblast cultured with powder suspension. In conclusion, hydroxyapatite and biphasic calcium phosphate appeared to be a bone graft substitute material with optimal biocompatibility and could be further applied to clinical use as an artificial bone graft substitute.

• 생명과학회지
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• 제21권2호
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• pp.300-308
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• 2011

톳은 새로운 생리활성 물질을 생산할 수 있는 소재로 각광받고 있으며, mouse calvaria 유래의 MC3T3-E1 세포는 골세포의 세포 활성과 관련된 연구에서 유용하게 이용되어 왔다. 따라서 본 연구에서는 MC3T3-E1 세포를 이용하여 톳 분획물이 세포 증식에 미치는 영향과 ALP 활성, 조골세포의 골 형성을 위한 필수 인자인 collagen 합성 및 조골세포의 표식인자인 골 석회화 형성능에 미치는 영향에 대해 검토하였다. 각 분획물의 수율은 aqueous 분획물이 47.4%로 가장 높은 수율을 나타내었으며 다음으로 butanol 분획물, methanol 분획물 순으로 나타났으며, hexane 분획물이 4.7%로 가장 낮은 수율을 나타내어 극성 성분의 함유량이 더 높은 것으로 확인되었다. 톳분획물의 농도(1, 10 50, 100 ${\mu}g$/ml)에 따른 조골세포 성장에 미치는 영향을 MTT assay로 분석한 결과, 모든 분획물에서 대조군과 비교하여 120% 정도의 증식률을 나타내었다. 이는 선행연구자에 의한 대두 에탄올 추출물 실험 결과인 최고 117%의 세포 증식률과 비슷한 조골세포 증식유도 결과임을 확인할 수 있었다. 톳 분획물이 ALP 활성에 미치는 영향을 조사한 결과, 톳 분획물 중 hexane 분획물과 butanol 분획물이 조골세포의 ALP 활성을 증가시켰으며, 특히 butanol 분획물은 120% 이상의 ALP 활성을 증가시켜 조골세포의 분화에 영향을 줄 가능성이 제시 되었다. 톳 분획물이 조골세포의 collagen 합성에 미치는 실험결과에서 모든 분획물에서 유의적인 collagen 합성능력을 나타내었다. 또한 조골세포의 골 석회화 형성에 미치는 영향은 methanol 분획물을 제외한 다른 분획물에서 유의적인 형성능을 보였으며, 특히 butanol 분획물을 100 ${\mu}g$/ml 첨가하였을 때는 281.25%, aqueous 분획물을 100 ${\mu}g$/ml 첨가하였을 때는 240.46%로 높은 골 석회화 형성능을 나타냈다. 따라서 톳 분획물이 조골세포의 증식, ALP 활성, collagen 합성 및 골 석회화 형성을 촉진하여 골 생성에 영향을 줄 수 있는 것이 확인되었으며, 구체적인 기작 연구와 in vivo 연구가 병행된다면 골다공증 예방과 관련된 기능성 식품의 천연소재로 개발이 가능하리라 사료된다.

• 한국식품조리과학회지
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• 제28권3호
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• pp.311-318
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• 2012

The correlation between osteoporosis and reactive oxygen species (ROS)-induced oxidative stress was investigated. Thus, interest in food and plants with antioxidant effects that can reduce damage caused by ROS during bone metabolism is heightening. In this study, the antioxidant effect of Taraxacum mongolicum on proliferation and differentiation of MC3T3-E1 cells under H2O2-induced oxidative stress was studied to investigate its protective effect against oxidative stress and its availability as an antioxidant material related to bone diseases. As a result, total polyphenol and total flavonoid contents of T. mongolicum were 33.65 mg/g and 4.45 mg/g, respectively. The T. mongolicum extract increased proliferation of both MC3T3-E1 cells and differentiated osteoblasts under $H_2O_2$-induced oxidative stress conditions. In addition, two differentiation markers, alkaline phosphatase activity and mineralization level in the T. mongolicum extract, tended to increase. These results indicate that T. mongolicum extract suppressed the damage to osteoblasts under oxidative stress and that it is potential antioxidant materials for preventing bone diseases.

• 한국임상수의학회지
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• 제38권2호
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• pp.94-97
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• 2021

An 18-year-old warmblood gelding was presented to Jeju National University Equine Hospital with chronic bilateral forelimb lameness. Navicular syndrome was suspected based on clinical findings, the hoof test, palmar digital nerve block, and radiographic results. Computed tomography (CT) was performed under general anesthesia. Bone cysts, enlarged vascular channels, sclerosis, and enthesophytes were identified in the navicular bone on CT images. Mineralization in the deep digital flexor tendon was also observed. CT can be a useful diagnostic tool for identifying lesions of the navicular bone and adjacent structures in horses. The horse was treated with an intra-bursal injection of triamcinolone and gentamicin. Lameness started to improve two days later and the horse was sound after two months of the injection. CT enabled us not only to diagnosis of navicular syndrome but also to determine the degree and extent of the lesions.

• Journal of Life Science
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• 제12권1호
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• pp.1-8
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• 2002

Antlers from deer species are alternative animal by-products. Due to the oriental trade, the velvet antler industry is rapidly emerging in North America. The unique biological property of antler wish a deciduous natural phenomenon offers the valuable model of biomedical research. Growing antlers showed different structures according to cell populations consisting of mesenchymes, chondroblasts, chondrocytes and osseous tissues from distal to proximal portions of main beam. Their structures were different from two tissues, cartilage and bone, in growing antlers. Zone of maturing ants calcifying chondrocytes referred as upper section was invaded by osteoblasts indicating the occurrence of endochondral ossification. The cartilaginous tissues were gradually replaced by osseous tissues downward. The bony tissues referred as the middle and base sections in this thesis contained spongy bone and cortical bone structure in the difference of the degree of mineralization antral the thickness of cortical bony in adjacent to outer velvet layer. In addition, the endocrinological regulators such as testosterone, prolactin, growth hormones and other growth factors are actively involved in the unique deciduous nature shown in the growth and development of antler.