Application of biomimetic mineralized collagen bone graft material on rabbits posterolateral spinal fusion / 中国修复重建外科杂志

Objective: To investigate the bone repair and regeneration ability of biomimetic mineralized collagen bone graft material and autologous bone marrow in rabbit posterolateral spinal fusion model. Methods: Twenty-seven 20-week-old male New Zealand white rabbits ［weighing (5.0±0.5) kg］ were used to establish the posterolateral spinal fusion model of L 5 and L 6 segments by stripping the transverse process and exposing cancellous bone with electric burr. The rabbits were randomly divided into 3 groups, 9 in each group. Groups A, B, and C were implanted 1.5 mL autologous iliac bone, 1.5 mL (30 mm×10 mm×5 mm) biomimetic mineralized collagen bone graft material, and 1.5 mL (30 mm×10 mm×5 mm) biomimetic mineralized collagen bone graft material and autologous bone marrow in each bone defect. At 4, 8, and 12 weeks after operation, the apparent hardness of the bone grafting area was observed by manipulation method, in order to evaluate bone graft fusion effects. Three animals were sacrificed in each group at each time point, the vertebral body specimens were excised and the bone defect repair and fusion were observed by X-ray films, and three-dimensional CT examination was performed to evaluate whether new bone was formed in the body. HE staining was performed at each time point to observe the formation of new bone and the repair and fusion of bone defects. Results: The manipulation test showed that bone graft fusion was not found in all groups at 4 weeks after operation; 3 (50.0%), 2 (33.3%), and 4 (66.7%) of groups A, B, and C reached bone graft fusion at 8 weeks after operation; 5 (83.3%), 4 (66.7%), and 5 (83.3%) of groups A, B, and C reached bone graft fusion at 12 weeks after operation; the fusion rate of group C was similar to that of group A, and all higher than that of group B. X-ray film observation showed that the fusion rate of group C at 8 and 12 weeks after operation was higher than that of group B, similar to group A. Three-dimensional CT observation showed that the effect of bone fusion in group C was better than that in group B, which was close to group A. HE staining observation showed that large area of mature lamellar bone coverage appeared in the bone graft area of groups A, B, and C at 12 weeks after operation, the material was completely degraded, and the marginal boundary of the host bone disappeared and tightly combined. Conclusion: Biomimetic mineralized collagen bone graft material mixed with autologous bone marrow has good osteoinduction and osteogenesis guidance. Compared with biomimetic mineralized collagen bone graft material, it has better and faster osteogenesis effect, which is close to autologous bone transplantation.

Research progress on osteoinductive properties of bone substitute materials / 口腔疾病防治

@#Bone graft material is not only a simple scaffold frame, but also a material with the potential to induce cells grow and differentiate into osteoblasts. The material with excellent bone induction properties can accelerate the healing of bone defect, thus repair the large area of bone defect successfully. Currently, plenty of researches regarding the bone induction in bone graft material have been reported, how to maximize the material osteoinductive potential, and to take advantage of these biological materials to produce the next generation of innovative biological material, is the current concerns. In this paper, a review is made on the bone induction properties of several kinds of bone substitutes.

The Effect of Poloxamer 407-Based Hydrogel on the Osteoinductivity of Demineralized Bone Matrix

BACKGROUND: Demineralized bone matrix (DBM) is used for bone healing due to its osteoinductivity, but it requires a carrier for clinical application. Here, we report the effects on the osteoinductivity of DBM by use of a poloxamer 407-based hydrogel as the carrier, compared to sterile water. METHODS: DBM-W and DBM-H represent 27 wt% of DBM with sterile water and DBM with a poloxamer 407-based hydrogel, respectively. Both of the compositions were applied to human mesenchymal stem cell (MSC) cultures, and monitored for alkaline phosphatase (ALP) staining and ALP activity. Six 10-week-old athymic nude rats were used for abdominal muscle grafting with either DBM-W or DBM-H, and were tested by plane radiography, microfocus X-ray computed tomography (CT), and decalcified histology to evaluate ectopic bone formation. RESULTS: The DBM-W group showed stronger ALP staining at 7, 14, and 21 days of treatment, and significantly higher ALP activity at 7 and 14 days of treatment, compared to the DBM-H group. Plane radiography could not confirm the radio-opaque lesions in the rat ectopic bone formulation model. However, ectopic bone formation was observed in both groups by micro-CT. Compared to the DBM-H group, the DBM-W group showed higher bone volume, percent bone volume and trabecular number, and the difference in percent bone volume was statistically significant. Decalcified histology found bony tissue with lamellation in both groups. CONCLUSIONS: Our results suggest that poloxamer 407-based hydrogel has efficacy as a DBM carrier since it shows ectopic bone formation, but its effects on the quality and quantity of osteoblastic differentiation in rat abdominal ectopic bone and MSC are considered negative.

Biomimetic Polymer Scaffolds to Promote Stem Cell-Mediated Osteogenesis

Bone tissue engineering using stem cells with osteogenic potential is a promising avenue of research for bone defect reconstruction. Organic, inorganic, and composite scaffolds have all been engineered to provide biomimetic microenvironments for stem cells. These scaffolds are designed to promote stem cell osteogenesis. Here, we review current technologies for developing biomimetic, osteoinductive scaffolds for stem cell applications. We summarize the reported in vitro and in vivo osteogenic effects of these scaffolds on stem cells.

Osteoblast response to commercially available demineralized bone matrices - An in-vitro study.

Objective: Reconstruction of lost attachment apparatus is a major goal of periodontal therapy. Although various osteoinductive bone replacement grafts (BRGs) have been used with apparent clinical success, unequivocal evidence of osteoinductivity may be obtained only through the demonstration of increased osteoblastic/osteoclastic differentiation following exposure to these materials. Materials and Methods: Bone marrow stem cells (BMSCs) obtained from rat femur were cultured in Dulbecco's Modified Eagles Medium (DMEM) and 10% fetal bovine serum (FBS). They were then exposed to two demineralized bone matrices (DBM's) - Grafton and Osseograft, and divided into three groups, comprising of a negative control (BMSC + DMEM + 10% FBS), Grafton, Osseograft. An osteogenic medium (OM) (10 hm dexamethasone, 10 hm b-glycerophosphate, and 50 μg/ml ascorbic acid) was added to create three subgroups comprising of a positive control (OM), Grafton with OM, Osseograft with OM. Results: After an initial phase (up to day 5), both Grafton and Osseograft induced an increased proliferative activity in the BMSCs, which reached a plateau after day 10. These grafts also induced increased alkaline phosphatase activity when compared to the control groups and to BMSCs with an OM. Conclusion: Both Osseograft and Grafton are capable of inducing osteoblastic proliferation and differentiation.

Effect of deproteinized bovine bone mineral soaked in inorganic polyphosphate on bone regeneration / 대한치주과학회지

This study was performed to evaluate the effect of deproteinized bovine bone mineral soaked in inorganic polyphosphate on bone regeneration in the calvaria of rabbit in the procedure of guided bone regeneration with titanium reinforced expanded polytetrafluoroethylene(TR-ePTFE) membrane. The rabbits were divided into four groups. Control group used TR-ePTFE membrane filled with deproteinized bovine bone mineral, experimental group I used TR-ePTFE membrane and deproteinized bovine bone mineral soaked in 4% inorganic polyphosphate, experimental group II and III used TR-ePTFE membrane and deproteinized bovine bone mineral soaked in 8% or 16% inorganic polyphosphate respectively. After decortication in the calvaria, GBR procedure was performed on 8 rabbits with only TR-ePTFE membrane or titanium reinforced ePTFE membrane filled with deproteinized bovine bone mineral soaked in inorganic polyphosphate. The animals were sacrificed at 4 weeks, and 8 weeks after the surgery. Non-decalcified specimens were processed for histologic analysis, and new bone formation was assessed by histomorphometric as well as statical analysis. 1. Both control group and experimental group demonstrated increasing of new bone formation until 8weeks. 2. At 8 weeks, experimental group I and group II showed the significant difference compared to control group in new bone formation. Especially experimental group II showed the most increasing of new bone formation. 3. The higher concentration of inorganic polyphosphate filled, the more volume of bone formation promoted, but experimental group III did not reveal significant difference compared to contol group. 4. Deproteinized bovine bone mineral did not resorbed at all until 8 weeks. These results suggest that inorganic polyphosphate has a promoting effect on bone regeneration, possibly by enhancing osteoconductivity of the carrier and by increasing osteoinductivity of the defected alveolar bone tissue, but not as we respect.

Osteoinduction using by Human BMP-2-physio- functional Bioactive Ceramics / 대한정형외과학회잡지

PURPOSE: To assess the properties and the osteogenic potency of the calcium phosphate-recombinant human morphogenetic protein-2 (CaP-rhBMP-2 composite) on glass-ceramics. MATERIALS AND METHODS: Bioactive glass-ceramics,as a scaffold, and a calcium phosphate (CaP) solution (pH7.4) were prepared. Recombinant human bone morphogenetic protein-2 (rhBMP-2) was purified from CHO-K1 cells by transfecting the cells with BMP-2 cDNA. The glass-ceramics were soaked for 3 days at room temperature in saline, a CaP only solution, and a CaP solution containing rhBMP-2. Scanning electron microscopy (SEM), Fourier transform infrared reflection spectroscopy (FT-IR), thin film X-ray diffraction (TF-XRD) and immunofluorescent staining (IF) of the anti-human BMP-2 to composite-coated scaffold were performed to verify the characterization of the scaffold surface. In addition, RT-PCR of osteogenic marker gene and SEM photography were performed after adhering the mouse preosteoblast MC3T3-E1 cells in order to assess the osteoinductivity. RESULTS: CaP-rhBMP-2 composite was coated on the surface of glass-ceramics, as confirmed by SEM, FT-IR, TF-XRD spectrum, and IF. The CaP-rhBMP-2 composite on the glass-ceramic showed a globular shape covered with fine spikes while the CaP on the glass-ceramic showed a fine spike structure on the flat glass surface. The expression of collagen type I and alkaline phosphatase mRNAs had increased 4 hours after cell seeding. In addition, the level of osteocalcin mRNA expression had increased significantly by 3 days in the CaP-rhBMP-2 composite compared with the control and CaP group. The SEM photographs showed more active filopodia formation in the CaP-rhBMP-2 composite than the other groups. There was extensive newly synthesized extracellular matrix around the osteoblasts and CaP-rhBMP-2 composite nodule. CONCLUSION: The application of CaP-rhBMP-2 composite-surface coating technique on bioactive glass-ceramic is a powerful tool for osteoinduction.

Experimental study of BMP-2 derived peptide on osteogenic induction in BMSC in vitro / 中国矫形外科杂志

[Objective]To investigate the capability of synthesis BMP-2-derived peptide on osteogenic induction in bone marrow stem cells(BMSEs),and to evaluate the osteoinductivity of BMP-2-derived peptide in vitro.[Method]After segregating and cultivating four weeks Wistar rats marrow stromal cells in induction group were induced by osteogenasis medium containing 200 gg/ml BMP-2-derived peptide,and in non-inductional group BMSCs were still culture with DMEM medium.Following continue culture for 2~4 weeks,cells film preparation,alkaline phosphatase activity and calcium deposition were measured.Type I collagen(CoM)and osteopontin(OPN)mRNA expression were measured using real-time fluorescent quantitative polymerase chain reaction(FQ-PCR)technique.The capability of synthesis BMP-2-derived peptide on osteogenic induction of BMSCs was investigated.[Result]After inductived with BMP-2-derived peptide.BMSCs cultured survived well greatly changed in cell morphology,and showed a biological and morphologie characteristics similar to those of osteoblasts.The lever of alkaline phosphatase activity and calcium deposition increased.Col-Ⅰand OPN mRNA were expressed at higher level.In non-inductional group no conspicuous osteogenic induction was shown.[Conclusion]BMP-2-derived peptide can induce BMSCs to differentiate into osteoblasts.It has the similar capacity of osteogenic induction as nature BMP-2,so BMP-2-derived peptide is an ideal cell agent for bone tissue engineering,and can be available widely.