Bone remodeling in the Masquelet-induced membrane model of rat femur by modulation of H-type vessels by total flavonoids of rhizome drynariae / 中国组织工程研究

ABSTRACT

BACKGROUND:Several studies have found that the total flavonoids of rhizome drynariae can promote neovascularization in the induced membrane,improve the biological properties of the induced membrane,and accelerate bone remodeling in the induced membrane,but the related molecular mechanisms still need to be further explored. OBJECTIVE:To explore the effect of total flavonoids of rhizome drynariae on bone remodeling in rat femoral Masquelet-induced membrane model by regulating H-type blood vessels. METHODS:Thirty-six male Sprague-Dawley rats were stratified by body mass and then randomly divided into blank group,model group and traditional Chinese medicine group,with 12 rats in each group.A 4-mm femoral bone defect model was established in all the rats.Bone defects in the model group and traditional Chinese medicine group were filled with polymethylmethacrylate bone cement.At 6 weeks after modeling,the tail bone of the rats was implanted in the blank group,as well as in the other two groups after removal of bone cement.The traditional Chinese medicine group was given 157.5 mg/kg per day of total flavonoids of rhizome drynariae at 3 days after bone implantation,while the model and blank groups were given the same amount of saline by gavage until the 8th week after bone implantation.Bone graft samples were taken for relevant testing at 8 weeks after implantation. RESULTS AND CONCLUSION:X-ray films showed that in the blank group,the fracture line in the defect area was clear,and only a small amount of bone callus formed;in the model group,the bone defect area still existed,where discontinuous cortical bone was visible;in the traditional Chinese medicine group,the defect area was filled with newborn bone tissues,the bone marrow cavity and part of the cortical bone formed,and the fracture line disappeared.Micro-CT scans showed that the amount of new bone in the defect area was low in the blank group,the number of bone trabeculae in the defect area was significantly increased in the model group,and a large amount of new bone tissue was filled in the bone defect area in the traditional Chinese medicine group.Hematoxylin-eosin staining results showed that in the blank group,only a small amount of new bone formed in the defect area and the quality of osteogenesis was poor;in the model group,there was more new bone tissue in the defect area,but some fibrous connective tissues were interspersed within the bone tissue;and in the traditional Chinese medicine group,a large amount of new bone formed in the defect area and the quality of osteogenesis was the best.CD31/Emcn immunofluorescence double-labeling staining results showed that the number of H-type blood vessels in the newborn bone tissue in the bone defect area of the blank group was sparse and sparsely distributed;compared with the blank group,there were more H-type blood vessels in the bone tissue in the bone defect area of the model group,and the blood vessels were distributed in relatively regular strips;the number of H-type blood vessels in the bone defect area of the traditional Chinese medicine group was the highest and the blood vessels were densely distributed.To conclude,the total flavonoids of rhizoma drynariae can upregulate the expression of H-type blood vessels to enhance the angiogenic-osteogenic effect,improve the osteogenic efficiency of the rat femoral Masquelet induced membrane model,and promote bone remodeling.