| Objective With the experiment of repairing bone defect in rabbit's radius by using NHAC(nano-Hydroxyapatite/collagen) and NHAC combined with bFGF , the effect of NHAC in repairing bone defect in differern period and the effect of bFGF in bone defect repairing will be observed, and so that a good composite matrix for repairing bone defect in clinic could be found.Methods The experiment included 50 New Zealand rabbits totally.Both radius of 50 rabbits were established 10mm bone defects, and then implanted separately with NHAC combined with bFGF(right, experimental side) and NHAC only(left, control side). 10 of the 50 rabbits were sacrificed to examine postoperatively by X-ray ,bone density,and histology respectively at 2nd,4th,6th,8th and 12nd weeks to observe the bone formation with the purpose of comparing the different abilities of the two materials in bone defect repairing. ResultsObservation of X-ray graphics:The experimental sides had apparently osteogenic manifestation in earlier period of postoperation (2nd week) and formed mass bony callus in the 6th week of postoperation; All the bone defects got clinically cured in the 12th week of postoperation. The control sides had apparently osteogenic manifestation in the 4th week and formed mass bony callus in the 8th week of postoperation; The healing rate was about 80% in the 12th week after surgery.Observation of bone density:The material density of the experimental sides is higher than that of the control sides,and the density is getting higher and higher at 4th,6th,8th weeks after operation,and the density of the material in experimental sides is similar to the bone density of the rabbits itself.The material density in control sides begins to get higher at the 4th week,and get higher and higher at 6th,8th,12nd weeks,but the density of material is always lower than the bone density of the rabbits.Histological results:The experimental sides had active osteogenicity in the second week, and then began to form mass bony callus and Haversian system in the 6th~8th weeks of postoperation; In the 12th week after surgery, there appeared a lot of mature bony callus and signs of clinical cure. The control sides had signs of osteogenicity in the 4th week after surgery and the bony callus began to increase from 6th to 8th postoperative weeks. In the 12th postoperative week, there appeared mature bony callus and Haversian system.Conclusionsl.he NHAC matrix is a kind of bone-like composition and has hierarchical structure, high biodegradability, excellent osteoconductive property, and biocompatibility.And NHAC can be used as the material for the repairing of bone defect, and the matrix of bone tissue-engineering.2.The express of bFGF has a very important effect to the osteoblast, chondroblast, vascular endothelial cell, which provides bFGF a bright future in bone tissue engineering.bFGF is very important in trauma healing, tissue repairing, blood vessel formation, and tissue neogenesis.3.NHAC combined with bFGF is a good material for bone defect repairing.
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