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BACKGROUND:Silk fibroin/mesoporous glass ceramic composites have been reported to exert satisfactory repair outcomes in bone defects and hold good biocompatibility. However, the biosafety and preparation methods are rarely reported. OBJECTIVE:To investigate the preparation method and treatment outcomes of silk fibroin/mesoporous bioactive glass ceramic in skul repair. METHODS:Thirty-two Sprague-Dawley rats were enrol ed to establish the skul defect models and were thenrandomized into two groups:fibroin/mesoporous glass ceramic materials and silk fibroin were respectively implanted into the defect region in experimental and control groups. At 4 and 8 weeks after implantation, the CT examination and histological observation were performed. RESULTS AND CONCLUSION:CT examination showed that at 4 weeks after implantation, the defect area in the experimental group diminished in size, showing more dense new bones. The defect area of the control group was reduced, and a smal amount of new bones were observed. At 8 weeks after implantation, bone defect repair was completed in the experimental group, but not in the control group. The bone volume in the experimental group was significantly larger than that in the control group at different time points after implantation (P<0.05). Hematoxylin-eosin staining found that at 4 weeks after implantation, in the experimental group, there was new bone between the implant and the bone, which did not cause inflammation;there were few new bones and fibrous tissues in the control group. At 8 weeks after implantation, many new bones formed in the experimental group, with similar morphology to the host bone and the scaffold was degraded completely. Conversely, the implant material stil existed in the control group. In conclusion, the silk fibroin/mesoporous glass ceramic composite can promote bone repair.
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Objective To study the impacts of dynamic compressive stress on the mRNA expression of osteopontin ( OPN ),runt related gene 2 ( Runx2 ),osteocalcin ( OC ),osterix,alkaline phosphatase (ALP) and bone morphogenetic protein 2 (BMP-2) in the osteoblasts of Sprague-Dawley (SD) rats. Methods Osteoblasts extracted from skull periosteum tissue of neonatal SD rats were digested using trypsin and collagenase （Ⅰ）,then were subcultured and amplified in vitro.ALP staining and alizarin red staining were performed to identify the purified cells.The cells were treated with compressive stress at 20,50 or 100 mmHg for 24 h.The expression levels of OPN,Runx-2,OC,osterix,ALP and BMP-2 were measured and quantitatively analysed using a real-time quantitative polymerase chain reaction. Results Under 20 mmHg of dynamic compressive stress the expression levels of OPN,Runx2,OC,osterix,ALP and BMP-2 all were elevated compared with the control group.The peak expression oecured under 50 mmHg pressure. The expression levels did not change significantly compared with the control group under 100 mmHg pressure. Conclusions Moderate dynamic compressive stress can promote the expression of OPN,Runx-2,OC,osterix,ALP and BMP-2 mRNA in osteoblasts,which might be an important mechanism for promoting the union of fractures.
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BACKGROUND:Schwann cell is one of the major seed cells In peripheral nervous system and plays an important role in neural injury and neural disease.However,the source of Schwann cells is limited.And the purity of Schwann cells is affected due to the pollution of fibroblasts.Many purified methods have been proposed,but every one has its defect to satisfy the clinical demand.OBJECTIVE:To compare the differences among differential adhesion purified method,cold jet purified method,immunomagnetic beads selection purified method and G418 selection purified method to purify Schwann cells of neonatal rat in vitro.METHODS:Bilateral sciatic nerves of SD rats were harvested under sterile condition.Schwann cells were purified respectively using differential adhesion purified method,cold jet purified method,immunomagnetic beads selection purified method and G418 selection purified method.Cell viability was compared,and cell purity was determined by immunohistochemistry.RESULTS AND CONCLUSION:The purity of Schwann cells separated by differential adhesion method was low,but the viability was fair.The purity and viability of cells following cold jet method immunomagnetic beads selection method was high.The purity of cells separated by immunomagnetic beads selection methods was similar to that of cold jet method immunomagnetic beads selection method,but the cell viability was worse.The cell viability following G418 selection method was bad,but the purity was high.