Processo de neoformação óssea das membranas colágenas Bio-Gide® e Ossix Plus® em defeitos críticos de calvárias: uma análise histomorfométrica e microtomográfica / Bone neoformation process of Bio-Gide® and Ossix Plus® collagen membranes in critical calvaria defects: a histomorphometric and microtomographic analysis

Objetivo: comparar a neoformação óssea em defeitos críticos confeccionados em calvárias de ratos utilizando duas apresentações de membranas de colágeno porcino, Bio-Gide® e Ossix Plus® para o recobrimento da loja cirúrgica criada. Material e Método: trinta e dois ratos machos (Rattus novergicus, Albinus, Wistar) foram divididos entre os grupos BG (membrana de colágeno porcino Bio-Gide®, n=16) e OS (membrana de colágeno porcino Ossix Plus®, n=16). Foram realizados defeitos críticos de 8mm de diâmetro nas calvárias dos animais e estes foram recobertos com as membranas colágenas BG ou OS. Aos 15, 30 e 60 dias os animais foram sacrificados por sobredose anestésica e as amostras coletadas foram submetidas à análise histomorfométrica (t=15, n=8; t=30, n=8 e t=60, n=8) e microtomográfica (t=60, n=8). A análise histomorfométrica foi realizada de forma qualitativa e quantitativa. Os dados histométricos quantitativos e os da análise microtomográfica foram submetidos à estatística (p< 0,05). Resultados: a análise histomorfométrica não apontou diferença no desempenho entre as membranas BG e OS nos períodos de 15, 30 e 60 dias (p> 0,05). Para os dados qualitativos e quantitativos, aos 60 dias pós-operatórios, foram encontradas quantidades consideráveis da membrana OS quando comparada a BG, bem como no parâmetro macroscópico. A análise microtomográfica evidenciou médias superiores para BV, BV/TV, Tb.Th e i.S (p< 0,05) para o grupo OS. Conclusão: a membrana Ossix Plus® apresentou qualidade superior de neoformação óssea, além de permanecer a longo prazo na região dos defeitos críticos produzidos(AU)

Objective: to compare bone neoformation in critical defects made in rat calvaria using two presentations of porcine collagen membranes, Bio-Gide® and Ossix Plus® for covering the surgical pocket created. Material and Method: thirty-two male rats (Rattus novergicus, Albinus, Wistar) were divided between BG (Bio-Gide® porcine collagen membrane, n=16) and OS (Ossix Plus® porcine collagen membrane, n= 16). Critical defects of 8 mm in diameter were made in the animals' calvaria and they were covered with BG or OS collagen membranes. At 15, 30 and 60 days the animals were sacrificed by anesthetic overdose and the samples collected were submitted to histomorphometric (t=15, n=8; t=30, n=8 and t=60, n=8) and microtomographic (t=60, n=8) analysis. The histomorphometric analysis was performed qualitatively. Quantitative histometric and microtomographic data were submitted to statistics (p< 0,05). Results: the histomorphometric analysis showed no difference in performance between the BG and OS membranes in the periods of 15, 30 and 60 days (p> 0.05). For qualitative and quantitative data, at 60 days postoperatively, considerable amounts of OS membrane were found when compared to BG, as well as in the macroscopic parameter. The microtomographic analysis showed higher means for BV, BV/TV, Tb.Th and i.S (p< 0.05) for the OS group. Conclusion: the Ossix Plus® membrane showed superior bone neoformation quality, in addition to remaining longterm in the region of the critical defects produced(AU)

Chitin-fibroin-hydroxyapatite membrane for guided bone regeneration: micro-computed tomography evaluation in a rat model / 대한악안면성형재건외과학회지

BACKGROUND: In guided bone regeneration (GBR) technique, many materials have been used for improving biological effectiveness by adding on membranes. The new membrane which was constructed with chitin-fibroin-hydroxyapatite (CNF/HAP) was compared with a collagen membrane (Bio-Gide®) by means of micro-computed tomography. METHODS: Fifty-four rats were used in this study. A critical-sized (8 mm) bony defect was created in the calvaria with a trephine bur. The CNF/HAP membrane was prepared by thermally induced phase separation. In the experimental group (n = 18), the CNF/HAP membrane was used to cover the bony defect, and in the control group (n = 18), a resorbable collagen membrane (Bio-Gide®) was used. In the negative control group (n = 18), no membrane was used. In each group, six animals were euthanized at 2, 4, and 8 weeks after surgery. The specimens were analyzed using micro-CT. RESULTS: Bone volume (BV) and bone mineral density (BMD) of the new bone showed significant difference between the negative control group and membrane groups (P < 0.05). However, between two membranes, the difference was not significant. CONCLUSIONS: The CNF/HAP membrane has significant effect on the new bone formation and has the potential to be applied for guided bone regeneration.

The effect of bacterial cellulose membrane compared with collagen membrane on guided bone regeneration

PURPOSE: This study was to evaluate the effects of bacterial cellulose (BC) membranes as a barrier membrane on guided bone regeneration (GBR) in comparison with those of the resorbable collagen membranes. MATERIALS AND METHODS: BC membranes were fabricated using biomimetic technology. Surface properties were analyzed, Mechanical properties were measured, in vitro cell proliferation test were performed with NIH3T3 cells and in vivo study were performed with rat calvarial defect and histomorphometric analysis was done. The Mann-Whitney U test and the Wilcoxon signed rank test was used (alpha<.05). RESULTS: BC membrane showed significantly higher mechanical properties such as wet tensile strength than collagen membrane and represented a three-dimensional multilayered structure cross-linked by nano-fibers with 60 % porosity. In vitro study, cell adhesion and proliferation were observed on BC membrane. However, morphology of the cells was found to be less differentiated, and the cell proliferation rate was lower than those of the cells on collagen membrane. In vivo study, the grafted BC membrane did not induce inflammatory response, and maintained adequate space for bone regeneration. An amount of new bone formation in defect region loaded with BC membrane was significantly similar to that of collagen membrane application. CONCLUSION: BC membrane has potential to be used as a barrier membrane, and efficacy of the membrane on GBR is comparable to that of collagen membrane.

The Effect of Silk Fibroin Particles Coated with Hydroxyapatites on Bone Regeneration in the Rat Calvarial Defect Model

3-Dimensional Micro-Computed Tomography Study on Bone Regeneration with Silk Fibroin, rh-Bone Morphogenetic Protein Loaded-Silk Fibroin and Tricalcium Phosphate Coated-Silk Fibroin in Rat Calvaria Defect

Effect of rhBMP-2 produced by Escherichia coli expression system on bone formation in rat calvarial defects / 대한치주과학회지

PURPOSE: Recombinant human bone morphogenetic protein-2(rhBMP-2) has been evaluated as potential candidates for periodontal and bone regenerative therapy. In spite of good prospects in BMP applications, there is economically unavailable for clinical use in dental area. The purpose of this study was to evaluate the osteogenic effect of rhBMP-2 produced by E.coli expression system. MATERIALS AND METHODS: Eight-mm critical-size calvarial defects were created in 48 male Sprague-Dawley rats. The animals were divided into 6 groups of 8 animals each. Each group received one of the following: Negative control(sham-surgery control), positive control(absorbable collagen sponge(ACS) alone) and experimental(ACS loaded with rhBMP-2). Defects were evaluated by histologic and histometric parameters following 2- and 8-week healing intervals. RESULTS: The experimental group showed significant defect closure at 2 and 8weeks than the sham surgery and positive control groups. Moreover, the experimental group showed significantly greater new bone and augmented area than the other groups at both 2 and 8weeks. CONCLUSION: rhBMP-2 produced by E.coli expression system may be effective for bone regeneration.

Effects of rhBMP-2 with various carriers on bone regeneration in rat calvarial defect / 대한치주과학회지

PURPOSE: Bone morphogenetic protein (BMP) is a potent differentiating agent for cells of the osteoblastic lineage. It has been used in the oral cavity under a variety of indications and with different carriers. However, the optimal carrier for each indication is not known. This study evaluated the bone regenerative effect of rhBMP-2 delivered with different carrier systems. MATERIALS AND METHODS: 8 mm critical-sized rat calvarial defects were used in 60 male Sprague-Dawley rats. The animals were divided into 6 groups containing 10 animals each. Two groups were controls that had no treatment and absorbable collagen membrane only. 4 groups were experimentals that contained rhBMP-2 only and applied with absorbable collagen sponge(Collatape(R)), MBCP(R), Bio-Oss(R) each. The histological and histometric parameters were used to evaluate the defects after 2- or 8-week healing period. The shape and total augmented area were stable in all groups over the healing time. RESULTS: New bone formation was significantly greater in the rhBMP-2 with carrier group than control group. rhBMP-2/ACS was the highest in bone density but gained less new bone area than rhBMP-2/MBCP(R) and rhBMP-2/Bio-Oss(R). The bone density after 8 weeks was greater than that after 2 weeks in all groups. However, rhBMP-2 alone failed to show the statistically significant difference in new bone area and bone density compared to control group. Also MBCP(R) and Bio-Oss(R) particles remained after 8 weeks healing period. CONCLUSION: These results suggest that rhBMP-2 with carrier system is an excellent inductive agent for bone formation and we can use it as the predictable bone tissue engieering technique. Future study will likely focus on the kinetics of BMP release and development of carriers that is ideal for it.

Effects of Recombinant Human Bone Morphogenetic Protein-2 loaded Acellular Dermal Matrix on Bone Formation / 대한치주과학회지

INTRODUCTION: The purpose of this study was to evaluate the possibility of the acellular dermal matrix (ADM) as a barrier membrane for bone regeneration, and to evaluate the osteogenic effect of ADM as a carrier system for rhBMP-2 in the rat calvarial defect model. MATERIALS AND METHODS: An 8-mm, calvarial, critical-size osteotomy defect was created in each of 60 male Spraque-Dawley rats(weight 250~300g). Three groups of 20 animals, each received either rhBMP-2(0.025mg/ml) in an ADM carrier, ADM only, or negative surgical control. And each group was divided i nto 2- and 8 -weeks healing intervals. The groups were evaluated by histologic and histomorphometric parameters(10 animals/group/healing intervals). Data were expressed as means+/-standard deviations(m+/-SD). Comparisons between experimental and control groups were made using two-way ANOVA and post hoc t-test. Comparisons between 2 weeks and 8 weeks were made using paired t-test. The level of statistical difference was defined as P< 0.05. RESULTS: The ADM group and rhBMP-2/ADM group results in enhanced local bone formation in the rat calvarial defect at both 2 and 8 weeks. The amount of defect closure and new bone formation were significantly greater in the rhBMP-2/ADM group relative to ADM group(P<0.05). At 8 weeks, the majority of ADM in the defect was contracted, and integrated with surrounding host tissues. In addition, host cell infiltration and neovascularization of the ADM in the absence of an inflammatory response were observed, and the newly formed bone around ADM showed a continuous remodeling and consolidation. CONCLUSION: The results of the present study indicated that ADM may be used as a barrier membrane for bone regeneration and that may be employed as a delivery system for BMPs.

The Analysis of Bone regenerative effect with carriers of bone morphogenetic protein in rat calvarial defects / 대한치주과학회지

Bone morphogenetic proteins have been shown to possess significant osteoinSductive potential, but in order to take advantage of this effect for tissue engineering, carrier systems are essential. Successful carrier systems must enable vascular and cellular invasion, allowing BMP to act as a differentiation factor. The carrier should be reproducible, non-immunogenic, moldable, and space-providing, to define the contours of the resulting bone. The purpose of this study was to review available literature, in comparing various carriers of BMP on rat calvarial defect model. The following conclusions were deduced. 1. Bone regeneration of ACS/BMP, beta-TCP/BMP, FFSS/BMP, FFSS/beta-TCP/BMP, MBCP/BMP group were significantly greater than the control groups. 2. Bone density in the ACS/BMP group was greater than that in beta-TCP, FFSS, FFSS/beta-TCP carrier group. 3. Bone regeneration in FFSS/BMP group was less than in ACS/BMP, beta-TCP/BMP, MBCP/BMP group. However, New bone area of FFSS/beta-TCP/BMP carrier group were more greater than that of FFSS/BMP group. ACS, beta-TCP, FFSS, FFSS/beta-TCP, MBCP were used for carrier of BMP. However, an ideal carrier which was reproducible, non-immunogenic, moldable, and space-providing did not exist. Therefore, further investigation are required in developing a new carrier system.

The effect of chitosan/ACS on bone regeneration in rat calvarial defects / 대한치주과학회지

The ultimate objective of periodontal treatment is to get rid of an on-going periodontal disease and further regenerate the supporting tissue, which is already destroyed, functionally. Currently, the bone grafting operation using various kinds of bone grafting materials and the operation for induced regeneration of periodontal tissue using the blocking membrane are performed for regeneration of the destroyed periodontal tissue. However, there are respective limitations Galenical preparations, which are used for regeneration of periodontal tissue, has less risk of rejective reaction or toxicity that may be incidental to degradation and their effect is sustainable. Thus, in case they are applicable to a clinic, they can be used economically. Chitosan has such compatibility, biological actions including antibacterial activity, acceleration of wound treatment, etc., and excellent mechanical characteristics, which has recently aroused more interest in it. Also, it has been reported that it promotes osteogenesis directly or indirectly by functioning as a matrix to promote migration and differentiation of a specific precussor cell (for example, osteoblast) and further inhibiting the function of such a cell as fibroblast to prevent osteogenesis. In this study, the pure chitosan solution, which was obtained by purifying chitosan, was used. However, since this chitosan is of a liquiform, it is difficult to sustain it in a defective region. It is, therefore, essential to use a carrier for delivering chitosan to, and sustaining it gradually in the defective region. In the calvarial defect model of the Sprague-Dawley rat, it is relatively easy to maintain a space. Therefore, in this study, the chitosan solution with which ACS was wetted was grafted onto the defective region. For an experimental model, a calvarial defect of rat was selected, and a critical size of the defective region was a circular defect with a diameter of 8 mm. A group in which no treatment was conducted for the calvarial defect was set as a negative control group. Another group in which treatment was conducted with ACS only was set as a positive control group (ACS group). And another group in which treatment was conducted by grafting the pure chitosan solution onto the defective region through ACS which was wetted with the chitosan solution was set as an experimental group (Chitosan/ACS group). Chitosan was applied to the Sprague-Dawley rat's calvarial bone by applying ACS which was wetted with the chitosan solution, and each Sprague-Dawley rat was sacrificed respectively 2 weeks and 8 weeks after the operation for such application. Then, the treatment results were compared and observed histologically and histometrically. Thereby, the following conclusions were obtained. 1. In the experimental group, a pattern was shown that from 2 weeks after the operation, vascular proliferation proceeded and osteogenesis proceeded through osteoblast infiltration, and at 8 week after the operation, ACS was almost absorbed, the amount of osteogenesis was increased and many osteoid tissue layers were observed. 2. At 2 weeks after the operation, each amount of osteogenesis appeared to be 8.70.8 %, 13.62.3 % and 4.80.7 % respectively in the experimental group, the positive control group and the negative control group. Accordingly, it appeared to be higher in the Experimental group and the positive control group than in the negative control group, but there was no significant difference statistically (p<0.01). 3. At 8 weeks after the operation, each amount of osteogenesis appeared to be 62.26.1 %, 17.42.5 % and 8.21.4 % respectively in the experimental group, the positive control group and the negative control group. Accordingly, it appeared to be substantially higher in the experimental group than in the positive control group and the negative control group, and there was a significant difference statistically (p<0.01). As a result of conducting the experiment, when ACS was used as a carrier for chitosan, chitosan showed effective osteogenesis in the perforated defective region of the Sprague-Dawley rat's calvarial bone.