Application value of bone cement containing rhbFGF and RHBMP-2 in PKP treatment of osteoporotic lumbar compression fracture / 中国骨伤

OBJECTIVE@#To investigate the effect of bone cement containing recombinant human basic fibroblast growth factor (rhbFGF) and recombinant human bone morphogenetic protein-2 (rhBMP-2) in percutaneous kyphoplasty(PKP)treatment of osteoporotic vertebral compression fracture(OVCF).@*METHODS@#A total of 103 OVCF patients who underwent PKP from January 2018 to January 2021 were retrospectively analyzed, including 40 males and 63 females, aged from 61 to 78 years old with an average of (65.72±3.29) years old. The injury mechanism included slipping 33 patients, falling 42 patients, and lifting injury 28 patients. The patients were divided into three groups according to the filling of bone cement. Calcium phosphate consisted of 34 patients, aged(65.1±3.3) years old, 14 males and 20 females, who were filled with calcium phosphate bone cement. rhBMP-2 consisted of 34 patients, aged (64.8±3.2) years old, 12 males and 22 females, who were filled with bone cement containing rhBMP-2. And rhbFGF+rhBMP-2 consisted of 35 patients, aged (65.1±3.6) years old, 14 males and 21 females, who were filled with bone cement containing rhbFGF and rhBMP-2. Oswestry disability index (ODI), bone mineral density, anterior edge loss height, anterior edge compression rate of injured vertebra, visual analog scale (VAS) of pain, and the incidence of refracture were compared between groups.@*RESULTS@#All patients were followed for 12 months. Postoperative ODI and VAS score of the three groups decreased (P<0.001), while bone mineral density increased (P<0.001), anterior edge loss height, anterior edge compression rate of injured vertebra decreased first and then slowly increased (P<0.001). ODI and VAS of group calcium phosphate after 1 months, 6 months, 12 months were lower than that of rhBMP-2 and group rhbFGF+rhBMP-2(P<0.05), bone mineral density after 6 months, 12 months was higher than that of rhBMP-2 and group calcium phosphate(P<0.05), and anterior edge loss height, anterior edge compression rate of injured vertebra of group rhbFGF+rhBMP-2 after 6 months and 12 months were lower than that of group rhBMP-2 and group calcium phosphate(P<0.05). There was no statistical difference in the incidence of re-fracture among the three groups (P>0.05).@*CONCLUSION@#Bone cement containing rhbFGF and rhBMP-2 could more effectively increase bone mineral density in patients with OVCF, obtain satisfactory clinical and radiological effects after operation, and significantly improve clinical symptoms.

In vivo study on the repairment of distal femur defects in rabbit with nano-pearl powder bone substitute / 中南大学学报(医学版)

OBJECTIVES@#To evaluate the repairing ability of nano-pearl powder bone substitute in rabbit with defect of distal femur bone.@*METHODS@#Thirty-two New Zealand rabbits were randomly divided into four groups: a nano-pearl powder/recombinant human bone morphogenetic protein 2 (rhBMP-2)/hyaluronic acid group, a nano-pearl powder/hyaluronic acid group, a nano-pearl powder group and a blank control group (=8 in each group). A defect with the diameter of 7 mm and height of 10 mm was prepared at the distal femoral metaphysis line of the rabbit.Different bone substitutes were planted, and the effect of repair was evaluated by macroscopic observation, imaging examination, and histopathological examination.@*RESULTS@#The results of imageology showed that: the bone repairing effect in the nano-pearl powder/rhBMP-2/hyaluronic acid group was better than that in the pure pearl powder group and the nano-pearl powder/hyaluronic acid group, and which in the 3 experimental groups was better than that in the blank control group; The results of histology showed that: at the 4th, 8th and 12th weeks after the modeling operation, the speed of bone repair in the nano-pearl powder/rhBMP-2/hyaluronic acid group was faster than that in the pure pearl powder group and the nano-pearl powder/hyaluronic acid group, and which in the blank control group was far slower than that in the 3 experimental groups. The results of immunohistochemistry staining for osteocalcin antibody showed that: the osteogenic effect in the nano-pearl powder/rhBMP-2/hyaluronic acid group was better than that in the pure pearl powder group and the nano-pearl powder/hyaluronic acid group (both 0.05); however, there was significant difference between the pure pearl powder group and the blank control group (0.05), but the osteogenic effect in the nano-pearl powder/hyaluronic acid group was better than that in the pure pearl powder group and the blank control group (both <0.05).@*CONCLUSIONS@#Nano-pearl powder and its bone substitute can promote the repair of bone defect, and the nano-pearl powder which contains rhBMP-2 has better osteogenic and repairing effect on defect.

Recombinant human bone morphogenetic protein-2 combined with autologous bone grafting and fusion in the treatment of thoracolumbar tuberculosis / 中国组织工程研究

BACKGROUND: The efficacy and safety of recombinant human bone morphogenetic protein-2 (rhBMP-2) combined with autologous bone grafting for the treatment of spinal degenerative diseases such as lumbar spondylolisthesis, spinal canal stenosis and intervertebral disc herniation have been recognized, but few clinical studies have been conducted on the efficacy and safety in the treatment of spinal infectious diseases such as spinal tuberculosis. OBJECTIVE: To evaluate the clinical efficacy and safety of rhBMP-2 combined with autologous bone grafting for spinal tuberculosis. METHODS: Clinical data of thoracolumbar tuberculosis admitted in the First Affiliated Hospital of Guangzhou University of Chinese Medicine from November 2010 to May 2018 were retrospectively analyzed. All patients underwent posterior pedicle screw fixation plus bone graft for spinal fusion, with (experimental group) or without (control group) the use of rhBMP-2. In the experimental group, 33 patients were treated with posterior pedicle fixation and autologous bone graft for spinal fusion combined with rhBMP-2 (1 mg). In the control group, 35 patients underwent posterior pedicle fixation and autologous bone graft. Visual analogue scale, the American Spinal Injury Association (ASIA), perioperative complications and fusion rate were statistically analyzed. The study protocol was approved by the Ethics Committee of the First Affiliated Hospital, Guangzhou University of Chinese Medicine. Informed consent was obtained from each patient. RESULTS AND CONCLUSION: All patients were followed up for more than 1 year. During the follow-up period, no fracture or movement of the internal fixation or distinct collapse of the vertebral body were found. There was no significant difference between the two groups in terms of operative time, intraoperative blood loss, length of stay, and proportion of perioperative complications (P > 0.05). There was a significant improvement in visual analogue scale scores and ASIA grades in the two groups at 1 week and 1 year after operation (P 0.05). The fusion rate in the experimental group was significantly higher than that in the control group at 6 months after operation (P 0.05). These findings indicate that rhBMP-2 combined with autologous bone for the treatment of thoracolumbar tuberculosis can accelerate bone fusion with favorable efficacy and safety in a short time.

Development of Refolding Process to Obtain Active Recombinant Human Bone Morphogenetic Protein-2 and its Osteogenic Efficacy on Oral Stem Cells

BMP-2 is a well-known TGF-beta related growth factor, having a significant role in bone and cartilage formation. It has been employed to promote bone formation in some clinical trials, and to differentiate mesenchymal stem cells into osteoblasts. However, it is difficult to obtain this protein in its soluble and active form. hBMP-2 is expressed as an inclusion body in the bacterial system. To continuously supply hBMP-2 for research, we optimized the refolding of recombinant hBMP-2 expressed in E. coli, and established an efficient method by using detergent and alkali. Using a heparin column, the recombinant hBMP-2 was purified with the correct refolding. Although combinatorial refolding remarkably enhanced the solubility of the inclusion body, a higher yield of active dimer form of hBMP-2 was obtained from one-step refolding with detergent. The refolded recombinant hBMP-2 induced alkaline phosphatase activity in mouse myoblasts, at ED₅₀ of 300-480ng/ml. Furthermore, the expressions of osteogenic markers were upregulated in hPDLSCs and hDPSCs. Therefore, using the process described in this study, the refolded hBMP-2 might be cost-effectively useful for various differentiation experiments in a laboratory.

Sinus augmentation using rhBMP-2-loaded synthetic bone substitute with simultaneous implant placement in rabbits

PURPOSE: The aim of this study was to determine the effect of recombinant human bone morphogenetic protein-2 (rhBMP-2)-loaded synthetic bone substitute on implants that were simultaneously placed with sinus augmentation in rabbits. METHODS: In this study, a circular access window was prepared in the maxillary sinus of rabbits (n=5) for a bone graft around an implant (Ø 3×6 mm) that was simultaneously placed anterior to the window. Synthetic bone substitute loaded with rhBMP-2 was placed on one side of the sinus to form the experimental group, and saline-soaked synthetic bone substitute was placed on the other side of the sinus to form the control group. After 4 weeks, sections were obtained for analysis by micro-computed tomography and histology. RESULTS: Volumetric analysis showed that the median amount of newly formed bone was significantly greater in the BMP group than in the control group (51.6 mm3 and 46.6 mm3, respectively; P=0.019). In the histometric analysis, the osseointegration height was also significantly greater in the BMP group at the medial surface of the implant (5.2 mm and 4.3 mm, respectively; P=0.037). CONCLUSIONS: In conclusion, an implant simultaneously placed with sinus augmentation using rhBMP-2-loaded synthetic bone substitute can be successfully osseointegrated, even when only a limited bone height is available during the early stage of healing.

Demineralized dentin matrix combined with recombinant human bone morphogenetic protein-2 in rabbit calvarial defects

OBJECTIVES: The aim of this study was to compare the osteogenic effects of demineralized dentin matrix (DDM) combined with recombinant human bone morphogenetic protein-2 (rhBMP-2) in rabbit calvarial defects with DDM and anorganic bovine bone (ABB) combined with rhBMP-2. MATERIALS AND METHODS: Four round defects with 8-mm diameters were created in each rabbit calvaria. Each defect was treated with one of the following: 1) DDM, 2) ABB/rhBMP-2, or 3) DDM/rhBMP-2. The rhBMP-2 was combined with DDM and ABB according to a stepwise dry and dip lyophilizing protocol. Histological and microcomputed tomography (µCT) analyses were performed to measure the amount of bone formation and bone volume after 2- and 8-week healing intervals. RESULTS: Upon histological observation at two weeks, the DDM and ABB/rhBMP-2 groups showed osteoconductive bone formation, while the DDM/rhBMP-2 group showed osteoconductive and osteoinductive bone formation. New bone formation was higher in DDM/rhBMP-2, DDM and ABB decreasing order. The amounts of bone formation were very similar at two weeks; however, at eight weeks, the DDM/rhBMP-2 group showed a two-fold greater amount of bone formation compared to the DDM and ABB/rhBMP-2 groups. The µCT analysis showed markedly increased bone volume in the DDM/rhBMP-2 group at eight weeks compared with that of the DDM group. Notably, there was a slight decrease in bone volume in the ABB/rhBMP-2 group at eight weeks. There were no significant differences among the DDM, ABB/rhBMP-2, and DDM/rhBMP-2 groups at two or eight weeks. CONCLUSION: Within the limitations of this study, DDM appears to be a suitable carrier for rhBMP-2 in orthotopic sites.

Effects of Block Bone Substitutes Loaded with Escherichia Coli-Produced Recombinant Human Bone Morphogenetic Protein-2 on Space Maintenance and Bone Formation in Rat Calvarial Onlay Model

We aimed to evaluate the effects of onlay-type grafted human freeze-dried corticocancellous bone block (FDBB) and deproteinized bovine bone with collagen (DBBC) loaded with Escherichia coli-produced recombinant human bone morphogenetic protein-2 (ErhBMP-2) on space maintenance and new bone formation in rat calvaria. Collagen sponge (CS), FDBB, or DBBC disks (8×4 mm) with ErhBMP-2 (2.5 µg) were implanted onto the calvaria of male Sprague-Dawley rats, whereas CS with buffer was implanted onto the calvaria as controls (n=20/carrier). Rats were killed at 2 or 8 weeks post-surgery for histologic and histomorphometric analyses; total augmented area, new bone area, and bone density were evaluated. At both time-points, all ErhBMP-2 groups showed significantly higher new bone area and bone density than the control group (p<0.05). ErhBMP-2/FDBB and ErhBMP-2/DBBC groups showed significantly higher total augmented area than ErhBMP-2/CS group (8 weeks), and ErhBMP-2/FDBB group showed significantly higher new bone area and bone density than ErhBMP-2/DBBC group (p<0.05). ErhBMP-2/CS group showed the highest bone density (p<0.05). Combining ErhBMP-2 with FDBB or DBBC could significantly improve onlay graft outcomes, by new bone formation and bone density increase. Moreover, onlay-grafted FDBB and DBBC with ErhBMP-2 could be an alternative to autogenous block onlay bone graft.

Double-layer nanoparticles loaded with rhBMP-2 and SDF-1:Preparation,characterization and drug re-lease in vitro / 实用口腔医学杂志

Objective:To construct double-layered controlled release system containing SDF-1 and rhBMP-2 molecules and to study the release profile of the system in vitro.Methods:The polylactic acid/chitosan(PLA/CS)nanoparticles were prepared with “emulsification-solution evaporation method”,the preparation parameters were determined by orthogonal test design.The particle size was observed by nanoparticle size analyzer,the morphology of the nanoparticles was observed with electron microscope.Then rhBMP-2 and SDF-1 were loaded into the nanoparticles in the process of emulsification,the loading efficiency and encapsulation efficiency were calculated and in vitro release was observed.Results:The double-layer nanoparticles showed spherical geometry,smooth surface and complete separation. The average particle size of the nanoparticles was (542.33 ±14.38)nm;The drug loading and incorporation efficiency of rhBMP-2 were (82.41 ±1.05)% and (24.67 ±0.43)ng/mg,those of rhBMP-2 were (75.58 ±0.84)% and (22.63 ±0.41)ng/mg,respectively. The release time of the drug from the system sustained over at least 30 days,the release profile of both drugs showed “biphasic release”. The cumulative release rate of SDF-1 and rhBMP-2 was 72.85% and 91.01% in 30 days respectively.Conclusion:The SDF-1 and rh-BMP-2 loaded PLA/CS nanoparticles have excellent morphology,high entrapment and good sustained-release in vitro.

Recombinant Human Bone Morphogenetic Protein-2 in Posterolateral Spinal Fusion: What's the Right Dose?

STUDY DESIGN: Single center retrospective cohort analysis. PURPOSE: The goal was to evaluate the influence of varying amount of recombinant human bone morphogenetic protein 2 (rhBMP-2) per level on fusion rates and complications in posterolateral spinal fusions. OVERVIEW OF LITERATURE: rhBMP-2 has been utilized for lumbar posterolateral fusions for many years. Initial rhBMP-2 recommendations were 20 mg/level of fusion. Dose and concentration per level in current studies vary from 4.2 to 40 mg and 1.5 to 2.0 mg/mL, respectively. Variable fusion and complication rates have been reported. METHODS: Patients (n=1,610) undergoing instrumented lumbar spinal fusion (2003-2009) with utilization of rhBMP-2 were retrospectively evaluated. Patient demographics, body mass index (BMI), comorbidities, number of levels, associated interbody fusion, and types of bone void filler were analyzed. Fusions rates and nonunions were subdivided into number of levels and amount of rhBMP-2 used per level. RESULTS: Patients (n=559) were evaluated with 58.5% females having an average age of 63 years, BMI of 31 kg/m2. Number of levels fused ranged from 1 to 8. rhBMP-2 averaged 7.3 mg/level (range, 1.5-24 mg/level) based upon length of collagen sponge in relation to length of fusion levels. Patients with non-union formation had lower rhBMP-2 dose per level (p=0.016). A significant difference in non-union rate was found between patients undergoing fusion with 6 mg/level (9.1% vs. 2.4%, χ2=0.012). No significant differences were noted between 6-11.9 mg/level and ≥12 mg/level. No threshold was found for seroma formation or bone overgrowth. CONCLUSIONS: Previous recommendation of 20 mg/level of rhBMP-2 is more than what is required for predictable fusion rates of 98%. No dose related increase of infection, seroma formation, and bone overgrowth has been found. In order to provide variable dosing and cost reduction, industry generated rhBMP-2 kit size should be optimized.

Recombinant Human Bone Morphogenetic Protein-2 in Posterolateral Spinal Fusion: What's the Right Dose?

STUDY DESIGN: Single center retrospective cohort analysis. PURPOSE: The goal was to evaluate the influence of varying amount of recombinant human bone morphogenetic protein 2 (rhBMP-2) per level on fusion rates and complications in posterolateral spinal fusions. OVERVIEW OF LITERATURE: rhBMP-2 has been utilized for lumbar posterolateral fusions for many years. Initial rhBMP-2 recommendations were 20 mg/level of fusion. Dose and concentration per level in current studies vary from 4.2 to 40 mg and 1.5 to 2.0 mg/mL, respectively. Variable fusion and complication rates have been reported. METHODS: Patients (n=1,610) undergoing instrumented lumbar spinal fusion (2003-2009) with utilization of rhBMP-2 were retrospectively evaluated. Patient demographics, body mass index (BMI), comorbidities, number of levels, associated interbody fusion, and types of bone void filler were analyzed. Fusions rates and nonunions were subdivided into number of levels and amount of rhBMP-2 used per level. RESULTS: Patients (n=559) were evaluated with 58.5% females having an average age of 63 years, BMI of 31 kg/m2. Number of levels fused ranged from 1 to 8. rhBMP-2 averaged 7.3 mg/level (range, 1.5-24 mg/level) based upon length of collagen sponge in relation to length of fusion levels. Patients with non-union formation had lower rhBMP-2 dose per level (p=0.016). A significant difference in non-union rate was found between patients undergoing fusion with 6 mg/level (9.1% vs. 2.4%, χ2=0.012). No significant differences were noted between 6-11.9 mg/level and ≥12 mg/level. No threshold was found for seroma formation or bone overgrowth. CONCLUSIONS: Previous recommendation of 20 mg/level of rhBMP-2 is more than what is required for predictable fusion rates of 98%. No dose related increase of infection, seroma formation, and bone overgrowth has been found. In order to provide variable dosing and cost reduction, industry generated rhBMP-2 kit size should be optimized.

Bone Healing in Ovariectomized-rabbit Calvarial Defect with Tricalcium Phosphate Coated with Recombinant Human Bone Morphogenetic Protein-2 Genetically Engineered in Escherichia coli / 대한악안면성형재건외과학회지

PURPOSE: This study compares the bone formation ability of tricalcium phosphate (TCP) with and without recombinant human bone morphogenetic protein-2 (rhBMP-2) and assesses TCP as a carrier of rhBMP-2. METHODS: Bilateral round defects (diameter: 8.0 mm) were formed in the cranium of eight New Zealand white rabbits. The defects were grafted with TCP only (control group) or with rhBMP-2-coated TCP (experimental group). The animals were sacrificed at 1st week, 2nd week, 4th week, and 8th week postoperatively; two rabbits sacrificed each time. The skulls were harvested and subjected to radiographic and histological examination. RESULTS: Radiologic evaluation showed faster bone remodeling in the experimental group than in the control group. Histologic evaluation (H&E, Masson's trichrome stain) showed rapid bone formation, remodeling and calcification in the 1st and 2nd week in the experimental group. Immunohistochemical evaluation showed higher expression rate of osteoprotegerin, receptor activator of nuclear factor kappaB ligand, and receptor activator of nuclear factor kappaB in the experimental group at the 1st and 2nd week than in the control group. CONCLUSION: rhBMP-2 coated TCP resulted in rapid bone formation, remodeling, and calcification due to rhBMP-2's osteogenic effect. TCP performed properly as a carrier for rhBMP-2. Thus, the use of an rhBMP-2 coating on TCP had a synergic effect on bone healing and, especially, bone remodeling and maturation.

Acute Intravenous Injection Toxicity Study of Escherichia coli-Derived Recombinant Human Bone Morphogenetic Protein-2 in Rat

STUDY DESIGN: Prospective in vivo toxicity study. PURPOSE: To evaluate the conducted acute toxicity study of Escherichia coli (E. coli)-derived recombinant human bone morphogenetic protein-2 (rhBMP-2) with 6-weeks old Sprague-Dawley rats. OVERVIEW OF LITERATURE: rhBMP-2 has well-known osteoinductivity and it is used as a bone graft substitute. E. coli-derived rhBMP-2 can be mass-produced with relatively low costs. E. coli-derived rhBMP-2 facilitates osteoblastic differentiation and bone formation in vitro and in vivo. However, studies regarding side effects or toxicity of E. coli-derived rhBMP-2 have not been published. Thus, we conducted the acute toxicity study of E. coli-derived rhBMP-2 on 6-weeks old Sprague-Dawley rats. METHODS: One mg of BMP-2 was diluted in 0.285 mL of glycine buffer to prepare high BMP-2 concentrations (3.5 mg/mL). Intermediate (0.9 mg/mL) or low (0.35 mg/mL) concentrations of BMP-2 solution was prepared by serial dilutions. The compound was administrated at a dose of 0, 0.7, 1.8, 7 mg/kg by single intravenous injection to five of male and female rats. After the injection, the gross general observations including changes of body weight and histopathological analysis was performed for 14 days. RESULTS: No animal was found dead during the experiment and the body weight changes were both statistically insignificant in the control and experimental groups. No abnormal sign was shown in general observations and autopsy examinations. CONCLUSIONS: Thus, the lethal dose of E. coli-derived rhBMP-2 should be higher than 7 mg/kg with a single intravenous injection.

The effect of silk fibroin and rhBMP-2 on bone regeneration in rat calvarial defect model

INTRODUCTION: This study evaluated the capability of silk fibroin (SF) and recombinant human bone morphogenetic protein-2 loaded SF (SF-BMP) as a bone defect replacement matrix when grafted in a calvarial bone defect of rats in vivo. MATERIALS AND METHODS: A total 70 calvarial critical size defects (5.0 mm in diameter) made on 35 adult female Sprague-Dawley rats were used in this study. The defects were transplanted with (1) rhBMP-2 loaded silk fibroin graft (SF-BMP: 0.8+10 microg), (2) Silk fibroin (SF: 10 microg), and (3) no graft material (Raw). The samples were evaluated with soft x-rays, alkaline phosphatase activity, calcium/phosphate quantification, histological and histomorphometric analysis at postoperative 4 and 8 weeks. RESULTS: The SF-BMP group (48.86+/-14.92%) had a significantly higher mean percentage bone area than the SF group (24.96+/-11.01%) at postoperative 4 weeks.(P<0.05) In addition, the SF-BMP group (40.01+/-12.43%) had a higher % bone area at postoperative 8 weeks than the SF group (33.26+/-5.15%). The mean ratio of gray scale levels to the host bone showed that the SF-BMP group (0.67+/-0.08) had a higher mean ratio level than the SF group (0.61+/-0.09) at postoperative 8 weeks. These differences were not statistically significant.(P=0.168 and P=0.243, respectively) CONCLUSION: The rhBMP-2 loaded silk fibroin graft revealed fewer immunoreactions and inflammation as well as more new bone formation than the pure silk fibroin graft. Therefore, silk fibroin may be a candidate scaffold for tissue engineered 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.

Histological observation of periodontal tissue regeneration guided with collagen membrane combined with recombinant human bone morphogenetic protein-2 / 吉林大学学报(医学版)

Objective To explore the effect of collagen membrane combined with recombinant human bone morphogenetic protein-2(rhBMP-2) on periodontal tissue regeneration and repair in periodontal defect models of rats.Methods Eighteen male healthy Wistar rats,which were made experimental periodontal bone defects in the inferior incisors,were randomly divided into three groups:control group,collagen membrane group(Co),collagen membrane and rhBMP-2 group(Co/rhBMP-2).Two rats from each group were sacrificed at 4,6,8 weeks after operation.The mandibles were removed,and examined under light microscope.Results In Co/rhBMP-2 group: 4 weeks after operation,a large amount of bone formed in the defects;6 weeks later,new bone filled in the defects;8 weeks later,alveolar bone emerged,newly-formed periodontal ligament and cementum localized at the root edges,no gingival epithelium was observed.In Co group:4 weeks after operation,new bone formed at the edge of the defects;6 weeks later,a larger amount of bone and periost were observed;8 weeks later,a small amount of periodontal ligament and cementum localized at the root edges.In control group: 4 weeks after operation,there was a small amount of newly-formed bone at the edge of the defects;6 weeks later,collagen fibers were found at the edge of defects;8 weeks later,a small amount of periodontal tissue reached its original height and gingival epithelium proliferated obviously.Conclusion Collagen membrane combined with rhBMP-2 which has not only conductive effect but also effect of osteoinduction,can prevent the long-epithelium growing,maintain the growth gap,and promote periodontal tissue to regenerate.

Treatment of femoral neck fracture using modified cannulated screw with injectable BMP release system / 中国矫形外科杂志

[Objective]To treat the femoral neck fracture using cannulated screw and BMP release system in animals,and to evaluate the possibility of treating femoral neck fracture and provide experimental basis for clinical application.[Method]Eighteen mongeral were used in this study.The model of bilateral femoral neck dislocation fracture was established.The control side was fixed using cannulated screw,and the experiment side was fixed with cannulated screw and injectable BMP release system.At 4,8,12 weeks,6 animals were sacrificed at one time point respectively.Results were obtained through histology,radiography,scintimetry and gross observation.[Result]The fracture line was vague at four weeks,and at eight weeks the fracture line almost disappeared.It was healed completely at twelve weeks.Radiological study showed that the healing of the fracture in experimental side was better than that of the control side.There was the same result of observation in histology.[Conclusion]The cannulated screw combined with BMP used in the experiment is effective and feasible.It may not only provide strong internal fixation but also infuse growth factor into site of fracture.It would accelerate the reconstructing of the vascular supply to the femoral head after the fracture and promote the restoration of bone.

Effects of rhBMP_2 on differentiation of human dental pulp stem cells and expression of Delta protein in vitro / 吉林大学学报(医学版)

Objective To investigate the effects of rhBMP2 on the differentiation of human dental pulp stem cells and expression of Delta protein in vitro. provide a theoretical basis for research on human dental pulp stem cells. Methods Monocell suspension was separated from the human adult dental pulp with collagenase Ⅰ and dispase digestion.Clonogenic cells were observed under light microscope and the expressions of surface markers were determined with immunofluorescence. divided into experimental group (containing 50 ?g?L-1rhBMP2 in the culture medium) and negative control group (containing culture medium only).alkaline phosphatase and the expression of Delta proterin of the cells at at passage 5 were detected.Results The human dental pulp stem cells showed colony growth,the nestin and vimentin staining were positive by immunohistochemical staining.STRO-1 was positive in cells by immunofluorescence.Compared with negative control group, the activities of alkaline phosphatase increased after treatment with rhBMP2 for 7,14 and 21d(P

Effect of human bone morphogenetic protein-2 on vascular endothelial growth factor expression in fetal mouse osteoblasts / 中华创伤骨科杂志

Objective To investigate effects of different doses of recombinant human bone morphogenetic protein-2 (rhBMP-2) on vascular endothelial growth factor (VEGF) expression in fetal mouse osteoblasts.Methods Calvaria osteoblasts of fetal mice of 19 days were cultured.The effects of rhBMP-2 at different doses and different action times on VEGF expression patterns in fetal mouse osteoblasts were observed with reverse transcrip- tion-polymerase chain reaction (RT-PCR) and Western blot staining.Results In the present study,RT-PCR detected a steady expression of VEGF mRNA in the control fetal mouse osteoblasts.The levels of VEGF mRNA increased in an apparent biphasic manner with a maximum stimulation (about 2-fold above the control,P＜0.05 ) in both VEGF mRNA species observed at 300 ng/mL of rbBMP-2.After 48 h of rhBMP-2 treatment,the VEGF mRNA levels approached those in the control.The VEGF mRNA levels appeared to be biphasic in rhBMP-2-treated cultures,showing peak induction at 3 and 24 h and remaining elevated at 48 b.Compared with the individual control value at each time point,an apparent maximum increase (about 2.5-fold above the control,P＜0.05) occurred at 6 h.The second peak induction,about 2-fold above that in the control,occurred at about 36 h.Conclusions The expression of VEGF mRNA is steady in the control fetal mouse osteoblasts.RhBMP-2 can promote the expression of VEGF in dose-dependent and time-dependent manners.

The effect of rhBMP-2 on the osteoblastic differentiation of human periodontal ligament cells and gingival fibroblasts in vitro / 대한치주과학회지

BMP can induce ectopic bone formation when implanted into sites such as rat muscle and can greatly enhance healing of bony defects when applied exogenously. In addition, BMP stimulated osteoblastic differentiation in vitro in various types of cells. The aim of this study was to investigate the effect of recombinant human bone morphogenetic protein(rhBMP-2) on the proliferation and osteoblastic differentiation of human periodontal ligament cells and gingival fibroblasts. The cell number and alkaline phosphatase activity were measured in 3 experimental groups of human periodontal ligament cells and gingival fibroblasts(control group, rhBMP-2 50ng/ml group, and rhBMP-2 100ng/ml group) at 1 and 2 weeks after culture. At the same time, total RNA of cultured cells were extracted and reverse trascription polymerase chain reaction(RT-PCR) was performed to determine the expression of mRNA of bone matrix protein. RhBMP-2 had no effect on the cell proliferation of human periodontal ligament cells and gingival fibroblasts. Alkaline phosphatase activity was elevated significantly by rhBMP-2 in both cells. And periodontal ligament cells showed significantly higher alkaline phosphatase activity than gingival fibroblasts. beta-actin, type I collagen, alkaline phosphatase, BMP-2 mRNA were expressed in all of the samples. Osteopontin, osteocalcin mRNA were expressed in all periodontal ligament cell groups, and rhBMP-2 50ng/ml group, rhBMP-2 100ng/ml group of 2 week culture period of gingival fibroblasts. Bone sialoprotein mRNA was only expressed in rhBMP-2 50ng/ml group and rhBMP-2 100ng/ml group of 2-week culture period. These results suggest that rhBMP-2 stimulates osteoblastic differentiation in human periodontal ligament cells and gingival fibroblasts in vitro.