• Maxillofacial Plastic and Reconstructive Surgery
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• v.29 no.3
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• pp.197-205
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• 2007

Angiogenesis is a essential part for bone formation and bone fracture healing. Vascular endothelial growth factor (VEGF), one of the most important molecules among many angiogenic factors, is a specific mitogen for vascular endothelial cells. VEGF-mediated angiogenesis is required for bone formation and repair. However, the effect of VEGF on osteoblastic cells during osteogenesis is still controversial. In recent days, substantial progress have been made toward developing tissue-engineered alternatives to autologous bone grafting for maxillofacial bony defects. Periosteum has received considerable interest as a better source of adult stem cells. Periosteum has the advantage of easy harvest and contains various cell types and progenitor cells that are able to differentiate into a several mesenchymal lineages, including bone. Several studies have reported the bone formation potential of periosteal cells, however, the correlation between VEGF signaling and cultured human periosteal cell-derived osteogenesis has not been fully investigated yet. The purpose of this study was to examine the correlation between VEGF signaling and cultured human periosteal-derived cells osteogenesis. Periosteal tissues of $5\;{\times}\;20\;mm$ were obtained from mandible during surgical extraction of lower impacted third molar from 3 patients. Periosteal-derived cells were introduced into the cell culture and were subcultured once they reached confluence. After passage 3, the periosteal-derived cells were further cultured for 42 days in an osteogenic inductive culture medium containing dexamethasone, ascorbic acid, and ${\beta}-glycerophosphate$. We evaluated the alkaline phosphatase (ALP) activity, the expression of Runx2 and VEGF, alizarin red S staining, and the quantification of osteocalcin and VEGF secretion in the periosteal-derived cells. The ALP activity increased rapidly up to day 14, followed by decrease in activity to day 35. Runx2 was expressed strongly at day 7, followed by decreased expression at day 14, and its expression was not observed thereafter. Both VEGF 165 and VEGF 121 were expressed strongly at day 35 and 42 of culture, particularly during the later stages of differentiation. Alizarin red S-positive nodules were first observed on day 14 and then increased in number during the entire culture period. Osteocalcin and VEGF were first detected in the culture medium on day 14, and their levels increased thereafter in a time-dependent manner. These results suggest that VEGF secretion from cultured human periosteal-derived cells increases along with mineralization process of the extracellular matrix. The level of VEGF secretion from periosteal-derived cells might depend on the extent of osteoblastic differentiation.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.4
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• pp.652-663
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• 1999

Craniosynostosis, the premature fusion of cranial sutures, presumably involves disturbance of the interactions between different tissues within the cranial sutures. Interestingly, point mutaions in the genes encoding for the fibroblast growth factor receptors(FGFRs), especially FGFR2, cause various types of human craniosynostosis syndromes. To elucidate the function of these genes in the early morphogenesis of mouse cranial sutures, we first analyzed by in situ hybridization the expression of FGFR2(BEK) and osteopontin, an early marker of osteogenic differentiation, in the sagittal suture of calvaria during embryonic(E15-E18) and postnatal stage(P1-P3). FGFR2(BEK) was intensely expressed in the osteogenic fronts, whose cells undergo differentiation into osteoprogenitor cells that ultimately lay down the bone matrix. Osteopontin was expressed throughout the parietal bones excluding the osteogenic fronts, the periphery of the parietal bones. To further examine the role of FGF-mediated FGFR signaling in cranial suture, we did in vitro experiments in E15.5 mouse calvarial explants. Interestingly, implantation of FGF2 soaked beads onto both the osteogenic fronts and mid-mesenchyme of sagittal suture after 36 hours organ culture resulted in the increase of the tissue thickness and cell number around FGF2 beads, moreover FGF4-soaked beads implanted onto the osteogenic fronts stimulated suture closure due to an accelerated bone growth, compared to FGF4 beads placed onto mid-mesenchyme of sagittal suture and BSA control beads. In addition FGF2 induced the ectopic expression of osteopontin and Msx1 genes. Taken together, these data indicate that FGF-mediated FGFR signaling has a important role in regulating the cranial bone growth and maintenance of cranial suture, and suggest that FGF-mediated FGFR signaling is involved in regulating the balance between the cell proliferation and differentiation through inducing the expression of osteopontin and Msx1 genes.

• Journal of dental hygiene science
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• v.13 no.2
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• pp.158-164
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• 2013

The most frequently encountered problems at fixture-implantation sites are lack of adequate bone and proximity to anatomic structures. It is generally accepted that growth factors play an essential role in the healing process and tissue formation, and they have become the focus of grafting materials research. The granules in platelets contain high concentrations of various growth factors. In particular, platelet-rich fibrin (PRF) is a second-generation platelet concentrate that allows the production of fibrin membranes enriched with platelets and growth factors from an anticoagulant-free blood harvest. This study investigated the in vitro effects of PRF on osteoblasts, in terms of the key cellular functions, and especially the effects on two growth factors, the homodimer of platelet-derived growth factor subunit B (BPDGF-BB) and transforming growth factor (TGF)-${\beta}1$, which are associated with wound healing and regeneration (i.e., proliferation and differentiation). The following parameters were investigated: PDGF-BB and TGF-${\beta}1$ levels in PRF, cell viability, alkaline phosphatase (ALP) activity, type 1 collagen synthesis, and the expressions of osteoblast differentiation markers (ALP and runt-related transcription factor 2) and bone matrix proteins (type 1 collagen). The release of autologous growth factors from PRF was maintained for a reasonable period of time, and exerted positive effects on the proliferation and differentiation of osteoblasts. The use of PRF thus appears to be a promising method for enhancing bone healing and remodeling.

• The Journal of Korean Academy of Prosthodontics
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• v.42 no.2
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• pp.175-191
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• 2004

Statement of problem: Platelet-rich plasma(PRP) is well known to be very effective method to stimulate and accelerate the healing of bone and soft tissue. However, there are few reports which deal with the mechanisms of the PRP on the activation of the osteoblasts. Purpose: This study was aimed to investigate the effect of growth factors in PRP on the activity of osteoblasts. Material and method: To evaluate the effect on human, human osteoblast cell line was cultured. PRP was extracted from the blood of a healthy volunteer. Using the recombinant growth factors of PDGF, $TGFT-\beta$, IGF-1, bFGF which are mainly found at bone matrix and their neutralizing antibody, the effect of PRP on the attachment and proliferation of osteoblasts was evaluated. To evaluate the autocrine and paracrine effects, conditioned media(CM) of PRP was made and compared with PRP. By the western blot analysis, the expression of growth factors in PRP, CM was examined. Cell morphology was compared by the light microscope. Results : 1) The effects of CM on osteoblast were similar to the effects of PRP. 2) PRP, CM, recombinant $TGF-\beta$, bFGF, IGF-1 showed significantly higher cellular attachment than control(p<0.05) in the cell attachment assay. In the cell proliferation assay, PRP, CM, recombinant $TGF-\beta$, IGF-1, bFGF, PDGF increased significantly cell proliferation(p<0.01). Among the recombinant growth factors, IGF-1 showed the highest cellular attachment and proliferation. 3) In the western blot assay, bFGF, IGF-1, PDGF weve equally expressed in PRP and CM. 4) The attachment of osteoblast cell decreased significantly after the addition of neutralizing antibody against $TGF-\beta$, IGF-1(p<0.05). In the cell proliferation assay, the addition of neutralizing antibody against $TGF-\beta$, bFGF, PDGF, IGF-1 decreased significantly the cellular proliferation(p<0.05). The amount of decreasing in the cell attachment and proliferation is the highest in at-lGF-1. 5) The cells in control group were flattened and elongated with a few cellular processes in the a light microscope. But, the cells appeared as spherical, plump cells with well developed cellular processes in experimental groups. The cells in PRP and CM had more prominent developed features than recombinant growth factor groups. Conclusions : These findings imply that PRP maximize the cellular activity in early healing period using the synergistic effect, autocrine, paracrine effects of growth factors and increase the rate and degree of bone formation.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.2
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• pp.87-93
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• 2010

Introduction: In our previous studies, we isolated porcine skin-derived mesenchymal stem cells (pSDMSCs) from the ears of adult miniature pigs and evaluated the pluripotency of these pSDMSCs based on expressions of transcription factors, such as Oct-4, Sox-2, and Nanog. Moreover, the characteristic of mesenchymal stem cells was revealed by the expression of various mesenchymal stem cell markers, including CD29, CD44, CD90, and vimentin. The aim of this study was to evaluate in vivo osteogenesis after maxillary sinus lift procedures with autogenous pSDMSCs and scaffold. Materials and Methods: The autogenous pSDMSCs were isolated from the 4 miniature pigs, and cultured to 3rd passage with same methods of our previous studies. After cell membranes were labeled using a PKH26, $1{\times}10^{7}$ cells/$100{\mu}L$ of autogenous pSDMSCs were grafted into the maxillary sinus with a demineralized bone matrix (DBM) and fibrin glue scaffold. In the contralateral control side, only a scaffold was grafted, without SDMSCs. After two animals each were euthanized at 2 and 4 weeks after grafting, the in vivo osteogenesis was evaluated with histolomorphometric and osteocalcin immunohistochemical studies. Results: In vivo PKH26 expression was detected in all specimens at 2 and 4 weeks after grafting. Trabecular bone formation and osteocalcin expression were more pronounced around the grafted materials in the autogenous pSDMSCs-grafted group compared to the control group. Newly generated bone was observed growing from the periphery to the center of the grafted material. Conclusion: The results of the present study suggest that autogenous skin-derived mesenchymal stem cells grafting with a DBM and fibrin glue scaffold can be a predictable method in the maxillary sinus floor elevation technique for implant surgery.

• Journal of Microbiology and Biotechnology
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• v.28 no.7
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• pp.1199-1208
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• 2018

Osteoarthritis is a disease that affects the articular cartilage and osseous tissue, and can be worsened by aging, overweight status, and post-traumatic arthritis. The present study aimed to evaluate the effect of ID-CBT5101 (tyndallized Clostridium butyricum) on bone metabolism and the inflammatory response in a monosodium iodoacetate-induced rat model of osteoarthritis. ID-CBT5101 was administered orally at doses of $10^8$ or $10^{10}CFU/day$ for 2 weeks before direct injection of monosodium iodoacetate ($3mg/50{\mu}l$ of 0.9% saline) into the intra-articular space of the rats' right knees. The rats subsequently received the same doses of oral ID-CBT5101 for another 4 weeks. We evaluated the treatment effects based on serum biomarkers, mRNA expression, morphological and histopathological analyses of the knee joints, and weight-bearing distribution analysis. Compared with those in control rats, the ID-CBT5101 treatments significantly reduced the serum concentration of inflammation and bone metabolism markers (i.e., COX-2, IL-6, $LTB_4$, and COMP), and significantly increased the concentration of $IFN-{\gamma}$ and glycosaminoglycans. In addition, the ID-CBT5101 treatments inhibited the mRNA expression of matrix metalloproteinases and tissue inhibitors of metalloproteinases (i.e., MMP-2, MMP-3, MMP-9, MMP-13, TIMP-1, and TIMP-2). Furthermore, the ID-CBT5101 treatments effectively preserved the knee cartilage and synovial membrane, and significantly decreased the amount of fibrous tissue. Moreover, compared with that of the negative control group, the ID-CBT5101 treatments increased the weight-bearing distribution by ${\geq}20%$. The results indicate that ID-CBT5101 prevented and alleviated osteoarthritis symptoms. Thus, ID-CBT5101 may be a novel therapeutic option for the management of osteoarthritis.

• The korean journal of orthodontics
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• v.18 no.1 s.25
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• pp.189-207
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• 1988

In almost all biologic systems, mechanically induced electric charge separation is a fundamental phenomenon. Since the hypothesis was established that the generation of electric potentials in bone by mechanical stress including muscular force might control the activity in bone by mechanical stress including muscular force might control the activity of osseous cells and their biopolymeric byproduct, the concept of electrically mediate growth mechanism, which involves biological growth and bone remodeling by any means, in living systems has been applied clinically and experimentally to orthopedic fracture repair, the regulation of orthodontic tooth movement, epiphyseal cartilage regeneration, etc. On the other hand, recent numerous research data available show apparently that the mandibular condyle has the characteristics of growth center as well as growth site. In addition, there exists a considerable difference of opinion as to the role of external pterygoid muscle in condylar growth. In view of these evidences, this. experiment was performed to investigate the effect of the galavic current on the growth of the mandible and condyle for elucidating the nature of condylar growth. The bimetallic device was composed of silver and platinum electrode connected with resistor (3.9 Mohm), which was expected to produce galvanic current of 23.6 nA according to the galvanic principle. The 25 Sprague-Dawley rats were divided into two group, 2 week group comprising 8 animals exposed to satanic current for 2 weeks and 3 control animals not exposed for 2 weeks, 4 week group comprising 10 animals in experimental group and 4 animals in control group applied for 4 weeks respectively. The experimental rats were subjected to application of the galvanic current invasively to codylar head surface and the control groups with sham electrode. On the basis of anatomic and histologic data from the mandibular condyle of experimental and control group, the following results were obtained. 1. After 2 weeks, there was no increase of mandibular size in experimental group over that of the control group. 2. After 4 weeks, the size of the condylar head was larger in experimental group than that of the control. 3. In 2 week group, the thickness of the mitotic compartment and hypertrophic chondroblastic layer was increased in experimental group. 4. In 4 week group, the number and the size of the hypertrophic chondroblasts were increased significantly on experimental group over that of the control group. 5. The application of the satanic current caused an increase in chondrocytic hypertrophy and intercellular matrix in both groups.

• Polymer(Korea)
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• v.35 no.6
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• pp.499-504
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• 2011

Articular cartilage has an intrinsic difficulty in recovering damages, which requires its tissue engineering treatment. Demineralized bone particle (DBP) contains various bioactive molecules. It is widely used biomaterials in the field of tissue engineering. We developed the synthetic/natural hybrid scaffolds with poly(lactide-co-glycolide) (PLGA) and solution of DBP. The chondrocytes were seeded on the PLGA-DBP scaffolds and MTT assay, morphological observation, biological assay for collagen, sGAG, and RT-PCR were performed to analyze the effect of the DBP on cell viability and extracellular matrix secretion. In SEM observation, we observed that PLGA-DBP scaffolds had uniform porosity. As MTT assay showed scaffolds containing DB solution had higher cell viability then only PLGA scaffolds. The PLGA-DBP scaffolds had better ECM production than PLGA scaffold. It was proven by the higher specific mRNA expression in the PLGA-DBP scaffold than that in PLGA scaffold. These results indicated that PLGA-DBP scaffolds might serve as potential cell delivery vehicles and structural bases for in vitro tissue engineered articular cartilage.

• Korean Journal of Head & Neck Oncology
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• v.23 no.1
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• pp.67-70
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• 2007

Myxoma is an uncertain mesenchymal cell origin, characterized by irregular round, stellate or spindle cells surrounded by the matrix containing abundant mucoid material and scant vascularity. Their occurrence in descending order of frequency is in the heart, subcutaneous tissue, bone and genitourinary tract. In the head and neck region, the most predilection sites are mandible and maxilla(more than 80%). Laryngeal myxoma is extremely rare：only 5 cases have been reported in the English literature. We report a rare case of laryngeal myxoma. A 60-year-old man with hoarseness visited the out-patient department. The mass was located between the vocal fold and the vocal ligament, filling with the left laryngeal ventricle. We planned the laryngo-microsurgery and successfully excised using $CO_2$ laser. The histopathologic finding revealed the myxoma. After 18 months of surgery, there is no evidence of recurrence and mucosal scarring in the vocal fold. This report is the first case of laryngeal myxoma involving the laryngeal ventricle and the true vocal cord together.

• Applied Microscopy
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• v.26 no.2
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• pp.177-195
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• 1996

Fine structure of the processes of intramembranous ossification and endochondral ossification at the tip of the distal phalanx of human fetuses was studied by electron microscopy. In 50 mm fetus, intramembranous ossification of the tip of cartilaginous phalanx was first noted. The osteoblasts of the perichondral zone of tip of cartilaginous phalanx started to lay down a thick membranous bony lamella. Most of the hypertrophied chondrocytes in the marginal parts of tip of the distal phalanx remained viable after being embeded in mineralized cartilaginous septa. The tuberosity of the distal phalanx was formed by membranous bony trabeculae on the exterior of the subperiosteal cap at 80 mm fetus. At this stage endochondral ossification was first observed in distal extremity of the distal phalanx. The maority of hypertrophied chondrocytes in the center of distal extremity appeared to be disintegrating. Resorption of calcified matrix was undertaken by perivascular cells and chondroclasts. From the periosteum, zone of calcification, vascular sprouts expanded within a recently opened lacunae, and the invading osteoblasts laid down osteoid and bone. After 120 mm fetus, endochondral and subperiosteal ossification proceeded in only one direction, just proximally. These findings demonstrate that intramembranous ossification, calcification, and endochondral ossification start at tip of the distal phalanx instead of at the center of the shaft, as was the case in other long bones.