RESUMEN
BACKGROUND: Preliminary study has shown that the composite materials composed of magnesium-based materials and mineralized collagen have a good supporting effect on repairing the critical defects, which can improve the mechanical strength of mineralized collagen and premature collapse during bone healing to some extent. However, magnesium-based metals degrade fast in chloride-containing solutions (including human body fluids or plasma), and the effects of releasing magnesium ions on the proliferation and differentiation of osteoblasts are unknown. OBJECTIVVE: To investigate the effects of magnesium ion combined with mineralized collagen on osteogenic differentiation of mouse preosteoblasts in vitro. METHODS: Mineralized collagen extracts were prepared from complete medium with magnesium ion concentration of 0, 5, 10, and 20 mmol/L. Mouse preosteoblasts were cultured with four mineralized collagen extracts, respectively, which were divided into mineralized collagen group, and 5, 10 and 20 mmol/L Mg2++mineralized collagen groups. The mouse preosteoblasts cultured in complete medium were used as control group. The cell morphology, proliferation, apoptosis, intracellular microfilament actin, and the activity of alkaline phosphatase and expression level of the osteogenic gene Runx2 after osteogenic differentiation were detected. RESULTS AND CONCLUSION: (1) After 24 hours of culture, the cells in the mineralized collagen group, and 5 and 10 mmol/L Mg2++ mineralized collagen groups adhered well, which showed no significant difference from the blank control group, and the elongated spindle cells with many synapses linked to the adjacent cells were observed. The cells in the 20 mmol/L Mg2++mineralized collagen group showed obvious pyknosis. (2) After 1, 3 and 5 days of culture, the cell viability in the 10 mmol/L Mg2++mineralized collagen group was significantly higher than that in the other four groups (P 0.05). The cell viability in the 20 mmol/L Mg2++mineralized collagen group was significantly lower than that in the mineralized collagen group (P < 0.05). (3) After 3 days of culture, DAPI staining showed that 20 mmol/L Mg2++mineralized collagen group had obvious nuclear disintegration, the other four groups had no obvious nuclear disintegration. (4) After 24 hours of culture, phalloidin staining showed that except the blank control and 20 mmol/L Mg2++mineralized collagen groups, the other three groups showed completely extended cell structure, and clear actin microfilaments, especially the 10 mmol/L Mg2++mineralized collagen group. (5) After 7 days of osteogenic differentiation, except for 20 mmol/L Mg2++mineralized collagen group, the activity of alkaline phosphatase and the expression level of Runx2 gene in the other three groups were significantly higher than those in the blank control group (P < 0.05), and those in the 10 mmol/L Mg2++mineralized collagen group was significantly higher than those in the 5 mmol/L Mg2++mineralized collagen and mineralized collagen groups (P < 0.05). (6) These results suggest that the combination of magnesium ion with mineralized collagen should be applied with appropriate concentration range of magnesium ion (≤ 10 mmol/L).
RESUMEN
BACKGROUND: Simple bone cement is easy to cause refracture of adjacent vertebra due to its high hardness. Currently, a material that can reduce the incidence of adjacent vertebra fracture is urgently needed. OBJECTIVE: To observe the clinical efficacy of percutaneous vertebroplasty using mineralized collagen modified bone cement. METHODS: Totally 60 patients with fresh single osteoporotic vertebral compression fractures who underwent percutaneous vertebroplasty were randomly divided into two groups, with 30 cases in each group. Patients in the simple bone cement group were given polymethyl methacrylate bone cement. Patients in the modified bone cement group were given mineralized collagen modified bone cement mixed with artificial bone repair material and simple polymethyl methacrylate bone cement. All patients signed the informed consent. This study was approved by the Hospital Ethics Committee. The follow-up time was 6-12 months. The clinical effect was assessed by the visual analogue scale, Oswestry Disability Index, Cobb angle and percentage of vertebral anterior edge height before surgery, at 2 days after surgery and during the last follow-up. Postoperative complications were recorded. RESULTS AND CONCLUSION: (1) All patients underwent successful operation. A total of four patients were found to have different degrees of bone cement leakage, and none of the patients presented obvious clinical discomfort symptoms. (2) Compared with pre-operation, visual analogue scale and Oswestry Disability Index were significantly improved (P 0.05) at 2 days after operation and during the last follow-up in the two groups. There were no significant differences in above indexes between the two groups at the same time point (P > 0.05). (3) The number of adjacent fractures in the simple bone cement group was more than that in the modified bone cement group, but there was no statistically significant difference in the incidence of adjacent vertebral fractures between the two groups (P > 0.05). (4) It is confirmed that compared with simple bone cement, mineralized collagen modified bone cement has no obvious disadvantages. In addition, mineralized collagen modified bone cement can give better biological properties while ensuring the strength of bone cement support and reducing pain. Further studies are needed to reduce the incidence of adjacent vertebral fractures.
RESUMEN
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.
RESUMEN
Objective:To study the feasibility of a new composite mineralized collagen membrane in alveolar ridge preservation.Methods:The third mandibular premolars on both sides were extracted from 12 dogs,the 24 alveolar sockets were randomly assigned into A,B and C groups(n =8).The distal alveolar sockets of group A was immediately implanted with the new composite mineralized collagen membrane and bone graft material,those of group B with bone graft material,group C was the blank control.The healing of sockets was evaluated by gross observation,morphological measurements,X-ray microscope and photographs of spiral CT.Results:The horizontal width of the alveolar process of group A was bigger than that of group B (P ＜ 0.05),that of group B was bigger than that of group C (P ＜ 0.05).The region of extraction interest in spiral CT value was higher in group A than that in group B and C (P ＜ 0.05).The extraction sockets were generated new bone and the degree of reconstruction measurements was higher in group A than that in group B and C (P ＜ 0.05).Conclusion:The new composite mineralized collagen membrane can induce the regeneration of new bone,and preserve the alveolar.
RESUMEN
Objective To prepare a novel bioactive and degradable scaffold with mineralized collagenpolyose based composite by biomimetic synthesis for bone tissue engineering and explore the compatibility of osteoblast culturing on the scaffold.Methods Using the cross-linking product of collagenⅠ and sodium hyaluronate as the template,the calcium phosphate was deposited on it to produce a mineralized composite.The 3-D porous scaffolds were prepared by liquid phase separation after the mineralized composite combining with polylactic acid (PLA) and NaCl.The materials and scaffolds were investigated by x-ray diffraction (XRD),scanning electronic microscopy (SEM) and universal testing machine.In addition,inverted microscope,fluorescence microscope,SEM,Cell Counting Kit-8 assay and alkaline phosphatase (ALP) assay were introduced to analyze the growth,function and compatibility(morphology,proliferation and differentiation ) of osteoblast-like cell on the scaffolds.Results The degree of hydroxyapatite (HA) crystals in the composite was low and the size was tiny,which were similar to that of nature bone.The SEM micrographs showed that the scaffolds possessed 82% of porosity and the pore size was about 200 μm to 650 μm.Cells on the scaffolds spread well and presented a high proliferation rate and differentiation level.Conclusion The novel scaffolds are simiar to nature cancellous (spongy) bone both on structure and in property and might be used as one of the optimal scaffolds material for bone tissue engineering.