• Journal of Periodontal and Implant Science
• /
• v.38 no.1
• /
• pp.59-66
• /
• 2008

Purpose: It has been shown that the inorganic polyphosphate is effective for the regeneration of bones through the preliminary animal test of rabbits. The most effective concentration of the polyphosphate, however, is not known yet. Moreover, the effectiveness of carriers inside human body is not confirmed.. Materials and Methods: In this study, we examined the effect of the concentration of the inorganic polyphosphate on the process of the bone regeneration using the 6 weeks old rabbits with the weight of 2.0 kg in average. We performed the experiment using TR-ePTFE membrane(membrane) filled with collagen immersed in 4%, 8% of inorganic polyphosphate, respectively, following removal of the proper sized cortical bones from the rabbit calvaria. The experimental results were compared with the one of the following four groups: The negative control group for membrane only, the positive control group for membrane filled with collagen, the first experimental group for membrane filled with collagen immersed in 4% of inorganic polyphosphate, and the second experimental group for membrane filled with collagen immerse in 8% of inorganic polyphosphate. The fragments of the tissue with membrane obtained from each group of the sacrificed rabbits for 8 or 16 weeks sustained after surgery were then prestained by the Hematoxylin-Eosin stain and coated by resin to form non-decalcified specimens for the histologic examination and analysis. New bone formation was assessed by histomorphometric and statistical analysis. Results: 1. All groups have shown better bone regeneration at 16weeks than 8weeks. 2. Negative control group has shown more bone regeneration relative to the other groups at 8 and 16 weeks. 3. All experimental groups have shown better bone regeneration relative to positive control group. 4. At 16 weeks, the first experimental group has shown more bone regeneration compared to the second experimental group. Exophytic bone formation is not good at the first and the second experimental groups compared with negative control group. But, the use of 4% inorganic polyphosphate was more effective to bone formation than the use of 8% inorganic polyphosphate. Conclusion: With above results, it is suggested the use of inorganic polyphosphate with vehicle under TR-ePTFE membrane.

• Journal of Periodontal and Implant Science
• /
• v.38 no.2
• /
• pp.153-162
• /
• 2008

Purpose: Recombining bone morphogenetic protein (BMP) is usually acquiredfrom high level animals. Though this method is effective, its high cost limits its use. The purpose of this study was to evaluate the effect of bone morphogenetic protein-2 with protein transduction domain (BMP-2/PTD;TATBMP-2) on bone regeneration. Rat calvarial defect model and osteoblastic differentiation model using MC3T3 cell were used for the purpose of the study. Materials and Methods: MC3T3 cells were cultured until they reached a confluence stage. The cells were treated with 0, 0.1, 1, 10, 100, 500 ng/ml of BMP-2/PTD for 21 days and at the end of the treatment, osteoblastic differentiation was evaluated usingvon Kossa staining. An 8mm, calvarial, critical-size osteotomy defect was created in each of 48 male Spraque-Dawley rats (weight $250{\sim}300\;g$). Three groups of 16 animals each received either BMP-2/PTD (0.05mg/ml) in a collagen carrier, collagen only, or negative surgical control. And each group was divided into 2 and 8 weeks healing intervals. The groups were evaluated by histologic analysis(8 animals/group/healing intervals) Result: In osteoblastic differentiation evaluation test, a stimulatory effect of BMP-2/PTD was observed in 10ng/ml of BMP-2/PTD with no observation of dose-dependent manner. The BMP-2/PTD group showed enhanced local bone formation in the rat calvarial defect at 2 weeks. New bone was observed at the defect margin and central area of the defect. However, new bone formation was observed only in 50% of animals used for 2weeks. In addition, there was no new bone formation observed at 8 weeks. Conclusion: The results of the present study indicated that BMP-2/PTD(TATBMP-2) have an positive effect on the bone formation in vitro and in vivo. However, further study should be conducted for the reproducibility of the outcomes.

• Journal of Korean Biological Nursing Science
• /
• v.3 no.2
• /
• pp.91-103
• /
• 2001

The bone is composed of the bone matrix of collagen and hydroxyapatite, the mixture of calcium and phosphours. The bone tissue is considered to the special connective tissue that possesses extracellular matrix made by collagen fiber deposited with mineral complex. In order to maintain bone mass measured by the sum of bone matrix and hydroxyapatite, bone resorption by osteoclast during lifetime and bone remodeling to form bone by osteoblast in its resorption region repeat continuously. The osteoblast has a mesodermic fetal origin like fibroblast for the formation of form tissues. Two cells express identical genes and synthesize the identical collagen type I as the major component of the formation of bone matrix and skin. Therefore, it is considered that the decrease of skinfold thickness and the decrease of bone mass related to the age, the change of two tissues composed of collagen type I is caused by the same genetic mechanism. The decrease of bone mass is caused by the change of the amount and structure of bone matrix by several factors and the amount of minerals deposited on bone matrix. Especially, in case of female, the deficiency of estrogen by menopause makes these changes rapidly increased. The decrease of bone mass and skinfold thickness is due to the decrease of the amount of collagen and its structural change the common component of bone tissue and skin tissue. Therefore, the relationship of the amount of cross-linked peptide N-telopeptide, collagen metabolite which excretes as urine. Based upon the proved results about the significant relationship of bone mass, the amount of bone collagen, the amount of skin collagen and skinfold thickness, the bone mass may be expected through a facile determination of skinfold thickness.

• Journal of Marine Bioscience and Biotechnology
• /
• v.7 no.2
• /
• pp.58-70
• /
• 2015

Injectable RGD-bioconjugated Mussel Adhesive Proteins (RGD-MAPs) composite hydroxypropyl methylcellulose (HPMC) hydrogels provide local periodontal tissue for bone filling in periodontal surgery. Previously we developed a novel type of injectable self-supported hydrogel (2 mg/ml of RGD-MAPs/HPMC) based porcine nano hydroxyapatite (MPH) for dental graft, which could good handling property, biodegradation or biocompatibility with the hydrogel disassembly and provided efficient cell adhesion activity and no inflammatory responses. Herein, the aim of this work was to evaluate bone formation following implantation of MPH and collagen membrane in rabbit calvarial defects. Eight male New Zealand rabbits were used and four circular calvarial defects were created on each animal. Defects were filled with different graft materials: 1) collagen membrane, 2) collagen membrane with MPH, 3) collagen membrane with bovine bone hydroxyapatite (BBH), and 4) control. The animals were sacrificed after 2 and 8 weeks of healing periods for histologic analysis. Both sites receiving MPH and BBH showed statistically increased augmented volume and new bone formation (p < 0.05). However, there was no statistical difference in new bone formation between the MPH, BBH and collagen membrane group at all healing periods. Within the limits of this study, collagen membrane with MPH was an effective material for bone formation and space maintaining in rabbit calvarial defects.

• Journal of Periodontal and Implant Science
• /
• v.31 no.4
• /
• pp.669-687
• /
• 2001

On the basis of the evidence that electrical stimulation could promote healing and regeneration of bone, this study was performed to investigate the effects of electrical stimulation on rat extraction socket, and to evaluate the potential of clinical application of electrical stimulation. Forty rats were used and divided into control groups(l0)and the experimental groups(30) in this study. The maxillary 1st molar were extracted in both groups. In experimental group, electrical stimulation was given at the current intensity of lmA(Test-1), l0mA(Test-2), 25mA(Test-3) each day. At 1,3,5,7 days after the tooth extraction, rats in both groups were serially sacrificed. And the specimens were prepared with Hematoxylin-Eosin stain for the light microscopic evaluation. The results of this study were as follows; 1. At 1 day after the extraction, the periodontal ligament was found in the extraction socket wall. The formation of blood clot with dense infiltration of inflammatory cells in control group and there were less inflammatory cells in test group. 2. At 3 day after the extraction, the cells and collagen of the periodontal ligament were so actively proliferated and synthesized that invaded into the connective tissue of the extraction sockets in the control group. There were the formation of new bone in the basal & lateral portion of socket wall in test -2 and -3. 3. At 5 days after the extraction, there were no formation of new bone in control group. But the more electrical stimulation was applied, the more formation of new bone in test group. 4. At 7 days after the extraction, the extraction sockets were almost filled with trabecular bone in each group. Bone maturarity was remarkable in test-3. 5. The electrical stimulation at l0mA and 25mA was more effective in the bone formation at 5 and 7 days after the extraction. From the above results, electrical stimulation could promote the extraction socket wound healing, and be utilized in the clinical application of the residual ridge expansion.

• Journal of Periodontal and Implant Science
• /
• v.30 no.1
• /
• pp.27-39
• /
• 2000

To evaluate the effects of Dexamethasone(Dex), Platelet derived growth factor-BB(PDGF) and combination of Dex and PDGF(DP) on the growth and differentiation of MC3T3-E1 cells, Dex($10^{-7}\;M$) and PDGF(10 ng/ml) in experimental group were added to the cells at the days 5, 10, 15, 20, 25 and examined for cell proliferation activities, DNA synthesis activities, ALP activities and bone nodule formation. The results were as follows : 1. In Dex group, cell proliferation, DNA synthesis and ALP activities were lower until 15 days when compared to the control group. Bone nodules formation were shown at 10 days. 2. In PDGF group, cell proliferation and DNA synthesis activities were higher until 15 days and ALP activities were lower when compared to the control and Dex groups. Bone nodules formation were shown at 20 days. 3. In DP group, cell proliferation and DNA synthesis activities of PDGF were suppressed by Dex and synergistic effects of combination of Dex and PDGF on ALP activities were shown at days 5 when compared to control and Dex groups. Bone nodules formation activities of Dex were suppressed by PDGF.

• Journal of Nutrition and Health
• /
• v.31 no.4
• /
• pp.716-728
• /
• 1998

To investigate the effect of dietary Ca levels on metabolic changes of Ca and skeleton in postmenopausal women, 10-month-old ovariectomized female rats were compared with 2 month old rats. The rats were fed either 0.2% or 1.2% Ca diets for 16 weeks. Food intake and weight gain as higher in rats fed high Ca diets and in ovariectomized rats. Apparent Ca absorption as higher, and Ca balance was lower in the low Ca groups. Vertebrae density was higher in old rats or those fed a high Ca diets. The old rats and ovariectomized rats showed decreased bone formation, increased bone resorption and kidney function deterioration resulting in increased urinary Ca excretion. Contradictory to the above observation, old rats and ovariectomized rats still showed higher bone mass and bone ash content. Therefore aging was not fully onging in 10-month-old rats. Bone weights, mineral contents, and mineral/wt ratio were lower in ovariectomized rats. Dietary Ca level did not affect urinary Ca excretion, urinary protein excretion, GFR, serum alkaline phosphatase, or urinary hydroxyporline excretion. This means that dietary Ca level did not influence kidney function or bone turnover. However Ca content and the ash content of femur, 4th vertebra, and scapula were increased in high Ca groups. Therefore, it is considered that decreased bone formation and accelerated bone resorption may account for the increased osteoporotic risk in women in menopause after middle age. However, Ca metabolism can be improved and bone components can be maintained if Ca is supplemented.

• Journal of Veterinary Clinics
• /
• v.34 no.6
• /
• pp.410-413
• /
• 2017

Composites of hydroxyapatite (HAp) and chitosan (CS) have been successfully used in bone healing in humans and animals. However, the characteristics of HAp and CS are different. Therefore, the effects of HAp/CS composites on canine bone formation could differ according to their ratio. This study investigated the therapeutic effects of different contents ratios (100, 80:20, 60:40 wt%) on bone defects in a canine model. Thirty intrabony cylindrical defects were created in the humeruses and femurs of 5 beagle dogs, and then the defects were implanted with different composites. The evaluations were performed using radiographs obtained at 10 weeks post-surgery and by histological findings. In radiographic evaluation including the grades of bone filling, periosteal and endosteal reactions, pure hydroxyapatite composite had a significant effect on bone filling, and chitosan containing the composites showed vigorous responses at the periosteum and endosteum. In histological findings, the defect implanted with pure hydroxyapatite had healed completely into mature bony tissue with an obvious osteon structure, and the defect implanted with chitosan containing the composites had the amount of fibrous connective tissue increased significantly within the cortical bone tissue. The results indicate that hydroxyapatite/chitosan composites are therapeutically useful, promoting effective bone healing in defects when the ratio of hydroxyapatite is high and enhanced fibrous connective tissue formation at the periosteum as more chitosan is added.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.18 no.3
• /
• pp.411-427
• /
• 1996

The purpose of this study was to observe the healing process and the distribution of fibronectin in injured condylar cartilage and bone by using LM and SEM. In order to perform this study, 40 male rat, weighing about 250g were selected. Under general anesthesia with Pentobarbital sodium, condylar cartilage and neck bone were resected. Then, the wound was irrigated with saline and closed with 5-0 chromic catgut and 4-0 silk by layer-to-layer suturing. The experimental rats were sacrificed by perfusion with 3% paraformaldehyde at 1st and 4th week after operation. The condylar process and surrounding tissues were cut, demineralized, dehydrated and embedded in paraffin. The histological observation of the specimens in LM level was performed after H-E stain and Azan stain. For localization of fibronectin, immunostaining was achieved by the avidin-biotin complex method. To study the change on condylar surface, the specimens were dehydrated, dried, gold coated and were observed with a scanning electron microscope(Hitachi S-2300). The results were as follows ; 1. The cartilage group and the bone group were repaired with epiphyseal cartilage layer on the cut surface as the normal control group. 2. The cut surface was repaired more quickly in the cartilage group than in the bone group. 3. Chondrocytes, diferentiated during healing, were stained strongly to anti-fibronectin, and fibronectin was supposed to participatein chondrocyte differentiation and cartilagenous matrix formation. 4. Fibronectin was distributed more in the new bone than in the old bone, and the osteoblasts surrounding it were also stained strongly. Fibronectin was supposed to participate in new bone matrix formation. 5. Fibronectin is supposed to be associated with the differentiation, migration and adhesion of chondrocyte and osteoblast and to participate in endochondral bone formation.

• Journal of Periodontal and Implant Science
• /
• v.34 no.2
• /
• pp.425-448
• /
• 2004

A bioactive and degradable poly(epsilon -caprolactone)/silica nanohybrid(PSH) was synthesized for the application as a bone substitute. PSH was manufactured by using silica and polycaprolacton. PSH was manufactured in some composition after low crystaline apatite had been formed in simulated body fluid and, was used this study. The safety of the PSH was established by test of acute, and subacute toxicity, sensitization cytotoxicity and sterility. In order to assess activity of osteoblast, the test for attaching osteoblast, proliferation test for osteoblast, differentiating gene expression test are performed in vitro. And bone substitutes were grafted in rabbit's calvarium, during 8 weeks for testing efficacy of bone substitutes. Degree of osteogenesis and absorption of substitutes were evaluated in microscopic level. In result, it was not appeared that acute and subacute toxicity, sensitization in intradermal induction phase, topical induction phase and challenge phase. It was shown that the test can not inhibit cell proliferation. adversely, it had some ability to accelerate cell proliferation. The result of sterility test described bacterial growth was not detected in most test tube. The attaching and proliferation test of osteoblast had good results. In the result of differentiating gene expression test for osteoblast, cbfa1 and, alkaline phosphatase, osteocalcin and GAPDH were detected with mRNA analysis. In the PSH bone formation test, ostgeoblastic activity would be different as material constitution but it had good new bone formation ability except group #218. futhermore, some material had been absorbed within 8 weeks. Above studies, PSH had bio-compatibility with human body, new bone formation ability and accelerate osteoblastic activity. So it would be the efficient bone substitute material with bio-active and biodegradable.