• Journal of Periodontal and Implant Science
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• v.40 no.3
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• pp.132-138
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• 2010

Purpose: The purpose of this study was to compare the bone regeneration effects of cortical, cancellous, and cortico-cancellous human bone substitutes on calvarial defects of rabbits. Methods: Four 8-mm diameter calvarial defects were created in each of nine New Zealand white rabbits. Freeze-dried cortical bone, freeze-dried cortico-cancellous bone, and demineralized bone matrix with freeze-dried cancellous bone were inserted into the defects, while the non-grafted defect was regarded as the control. After 4, 8, and 12 weeks of healing, the experimental animals were euthanized for specimen preparation. Micro-computed tomography (micro-CT) was performed to calculate the percent bone volume. After histological evaluation, histomorphometric analysis was performed to quantify new bone formation. Results: In micro-CT evaluation, freeze-dried cortico-cancellous human bone showed the highest percent bone volume value among the experimental groups at week 4. At week 8 and week 12, freeze-dried cortical human bone showed the highest percent bone volume value among the experimental groups. In histologic evaluation, at week 4, freeze-dried cortico-cancellous human bone showed more prominent osteoid tissue than any other group. New bone formation was increased in all of the experimental groups at week 8 and 12. Histomorphometric data showed that freeze-dried cortico-cancellous human bone showed a significantly higher new bone formation percentile value than any other experimental group at week 4. At week 8, freeze-dried cortical human bone showed the highest value, of which a significant difference existed between freeze-dried cortical human bone and demineralized bone matrix with freeze-dried cancellous human bone. At week 12, there were no significant differences among the experimental groups. Conclusions: Freeze-dried cortico-cancellous human bone showed swift new bone formation at the 4-week healing phase, whereas there was less difference in new bone formation among the experimental groups in the following healing phases.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.28 no.1
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• pp.42-45
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• 2002

Cultures of primary human alveolar bone-derived cells were established from alveolar bone chips obtained from normal individuals undergoing tooth extraction. These cells were expanded in vitro until passage 3 and used for the in vivo assays. Cells were loaded into transplantation vehicles, and transplanted subcutaneously into immunodeficient mice to study the capacities of human alveolar bone-derived cells to form bone in vivo. Transplants were harvested 12 weeks after transplantation and evaluated histologically. Of 10 human alveolar bone-derived cell transplants, two formed a bone-like tissue that featured osteocytes and mineral. Eight of the ten formed no osseous tissue. These results show that cells from normal human alveolar bone are capable of forming bone-like tissue when transplanted into immunodeficient mice.

• Archives of Plastic Surgery
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• v.32 no.3
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• pp.343-346
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• 2005

It has been established that a graft of fibroblasts is able to improve wound healing. However, there has been no research on the effect of a graft of bone marrow stromal cells on wound healing. The wound healing process requires cell proliferation and production of extracellular matrix and various growth factors. The purpose of this study was to compare the abilities of human fibroblasts and bone marrow stromal cells, which contains mesenchymal stem cells, to proliferate and to produce collagen. Human bone marrow stromal cells and fibroblasts were isolated from bone marrow and dermis of the same patients and grown in culture respectively. Cell proliferation and production of type I collagen by human bone marrow stromal cells and dermal fibroblasts were examined by MTT method and by ELISA of cell culture media on day 1, 3, and 5 days post-incubating. The human bone marrow stromal cells showed 11-17% higher cell proliferation than fibroblasts at each time interval. The levels of type I collagen in the human bone marrow stromal cell group was also significantly higher than those in the fibroblast group. The results indicate that the grafts of human bone marrow stromal cells can show more promising effect than that of fibroblasts for healing of chronic wounds.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.18 no.1
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• pp.164-174
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• 1996

In order to develop the allogeneic bone implants instead of autogenous bone grafts for maxillofacial reconstruction, undemineralized freeze-dried human bone was processed. The freeze-dried human bone was implanted into the cranial and mandibular defects of the rabbits. The implants were evaluated clinically, roentgenographically and histomophometrically. And immunohistochemical evaluation of the implants was performed on the rat. The results were as follows : 1. When compared with control defects of $0.8{\times}0.8\;cm$, the implants on the rabbit defects displayed complete osseous bridging clinically and roentgenographically. Histomophometrically a minimal inflammatory cell infiltrate was present but the defects healed well clinically. 2. When compared with control grafts, the freeze-dried implants on the rat muscle displayed decreased antigenicity by immunohistochemical evaluation, due to freeze-drying process. 3. Undemineralized freeze-dried human bone in this study can be preserved as a bank bone in this study and seems to be applicable for clinical allogeneic bone grafts.

• Molecules and Cells
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• v.38 no.3
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• pp.267-272
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• 2015

Nacre seashell is a natural osteoinductive biomaterial with strong effects on osteoprogenitors, osteoblasts, and osteoclasts during bone tissue formation and morphogenesis. Although nacre has shown, in one study, to induce bridging of new bone across large non-union bone defects in 8 individual human patients, there have been no succeeding human surgical studies to confirm this outstanding potency. But the molecular mechanisms associated with nacre osteoinduction and the influence on bone marrow-derived mesenchymal stem cells (BMSC's), skeletal stem cells or bone marrow stromal cells remain elusive. In this study we highlight the phenotypic and biochemical effects of Pinctada maxima nacre chips and the global nacre soluble protein matrix (SPM) on primary human bone marrow-derived stromal cells (hBMSCs) in vitro. In static co-culture with nacre chips, the hBMSCs secreted Alkaline phosphatase (ALP) at levels that exceeded bone morphogenetic protein (rhBMP-2) treatment. Concentrated preparation of SPM applied to Stro-1 selected hBMSC's led to rapid ALP secretions, at concentrations exceeding the untreated controls even in osteogenic conditions. Within 21 days the same population of Stro-1 selected hBMSCs proliferated and secreted collagens I-IV, indicating the premature onset of an osteoblast phenotype. The same SPM was found to promote unselected hBMSC differentiation with osteocalcin detected at 7 days, and proliferation increased at 7 days in a dose-dependent manner. In conclusion, nacre particles and nacre SPM induced the early stages of human bone cell differentiation, indicating that they may be promising soluble factors with osteoinductive capacity in primary human bone cell progenitors such as, hBMSC's.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.5
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• pp.453-456
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• 2001

Background: Autogenous alveolar bone cell transplantation may be suitable for tissue engineering for alveolar bone reconstruction. This study aimed to isolate human alveolar bone-derived cells (HABDCs) and to evaluate the ability of collagen gels to support HABDC proliferation and differentiation for human alveolar bone tissue engineering applications. Method: Cultures of primary HABDCs were established from alveolar bone chips obtained from 10 persons undergoing tooth extraction. These cells were expanded in vitro until passage 3 and used for the in vitro characterization of HABDCs and the in vitro analysis of collagen gels for alveolar bone tissue engineering. Results: Of the 10 attempts made to obtain HABDC cultures, eight were successful. HABDCs expressed the osteoblastic phenotype characterized by alkaline phosphatase activity, osteocalcin expression and the mineralization of the extracellular matrix in vitro. When seeded on collagen gels, HABDCs penetrated into the collagen gel matrices and proliferated inside the gels. Significantly, when HABDCs were embedded into the gels, collagen fibers and mineralization were produced within the gels. Conclusion: This study demonstrates the feasibility of using cultured HABDCs and collagen gels for human alveolar bone tissue engineering applications.

• Molecules and Cells
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• v.39 no.3
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• pp.186-194
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• 2016

Epidemiological evidence suggests that bone is especially sensitive to oxidative stress, causing bone loss in the elderly. Previous studies indicated that human amnion-derived mesenchymal stem cells (HAMSCs), obtained from human amniotic membranes, exerted osteoprotective effects in vivo. However, the potential of HAMSCs as seed cells against oxidative stress-mediated dysfunction is unknown. In this study, we systemically investigated their antioxidative and osteogenic effects in vitro. Here, we demonstrated that HAMSCs significantly promoted the proliferation and osteoblastic differentiation of $H_2O_2$-induced human bone marrow mesenchymal stem cells (HBMSCs), and down-regulated the reactive oxygen species (ROS) level. Further, our results suggest that activation of the ERK1/2 MAPK signal transduction pathway is essential for both HAMSCs-mediated osteogenic and protective effects against oxidative stress-induced dysfunction in HBMSCs. U0126, a highly selective inhibitor of extracellular ERK1/2 MAPK signaling, significantly suppressed the antioxidative and osteogenic effects in HAMSCs. In conclusion, by modulating HBMSCs, HAMSCs show a strong potential in treating oxidative stress- mediated bone deficiency.

• Journal of Biomedical Engineering Research
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• v.13 no.4
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• pp.353-362
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• 1992

The stress distribution of bone is altered by the rigid bone plate, sometimes resulting in unfavorable osteoporosis. The rigidity and the biocompatibility are important factors for the design of prosthesis. However, it is also necessary to consider the effect on the bone remodeling. In this paper, it is attempted to establish an approximate and simple method to predict the trend of the configuration of surface bone remodeling for the case of a bone plate using stress analysis. Thus, three dimensional finite element model of plated-human femur is generated and simulated. In addition. the stress difference method (SDM) is introduced and attempted to demonstrate the configuration of surface bone remodeling of the plated-human femur. The results are compared with those of invivo tests and the feasibility of the stress difference method is discussed.

• Oral Biology Research
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• v.42 no.4
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• pp.198-207
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• 2018

Guided tissue regeneration (GBR) has been used to promote new bone formation in alveolar bone reconstruction at defective bone sites following tooth loss. Bone grafts used in GBR can be categorized into autogenous, xenogenous, and synthetic bones, and human allografts depending on the origin. The purpose of this study was to compare the rates of bone regeneration using two different bone grafts in the cranial defects of rabbits. Ten New Zealand rabbits were used in this study. Four defects were created in each surgical site. Each defect was filled as follows: with nothing, using a 50% xenograft and 50% human freeze-dried bone allograft (FDBA) depending on the volume rate, human FDBA alone, and xenograft alone. After 4 to 8 weeks of healing, histological and histomorphometric analyses were carried out. At 4 weeks, new bone formation occurred as follows: 18.3% in the control group, 6.5% in group I, 8.8% in group II, and 4.2% in group III. At 8 weeks, the new bone formation was 14.9% in the control group, 36.7% in group I, 39.2% in group II, and 16.8% in group III. The results of this study suggest that the higher the proportion of human FDBA in GBR, the greater was the amount of clinically useful new bone generated. The results confirm the need for adequate healing period to ensure successful GBR with bone grafting.

• 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.