Osteogenic Potential And Repaired Effects In The Treatment Of Bone Defects By HA/TCP Combined With BMP Plus BFGF

Objective: To investigate the ability of osteogenesis, repaired effects and possible mechanism with the compound of HA/TCP(1:1),BMP and bFGF.Methods:1: HA/TCP(1:1) was combined with BMP and bFGF.2: Muscle pouches of the rabbits were implanted with HA/TCP+BMP+bFGF, HA/TCP+BMP and HA/TCP . The effect of ectopic bone formation was evaluated by histology, biochemical examination of Alkaline phosphatase in 2 weeks and 4 weeks after operation; and the new bone was weighted in in 2 weeks and 4 weeks of postoperation to compare the activity of bone formation.3: A 4mm×4mm×12mm bone defect experimental model in both thighbone of rabbits was made, the animals were divided into three groups at random, HA/TCP carrier with bovine BMP 15mg and bFGF 6000AU was implanted in the experiment group. HA/TCP carrier with bovine BMP 15mg was implanted in the control group A. And HA/TCP was implanted in the control groupB. In vestigation of the bone defect was made by means of gross observation. X-ray examination, histology of HE and Masson staining in 4 weeks, 8 weeks, 12 weeks after operation were studied and new bone formation was measured by Image analysis.Results:1.The activity and new bone quantity of experiment group(HA/TCP+BMP+bFGF) was significantly higher than in control group A(HA/TCP+BMP),control group B(HA/TCP)(P<0.01). Two week after experiment group, the chondrocy induced in muscle pouches, the woven b2. The bone defect in the experimental group has excellent repair than one was seen, and the trabecular bone was formed in four week.that seenin the control group A and control group B., both bone union and the period of bone mature were earlier than that seen in the control A and control groups B. In gross observation, the implantations were adhered to the host bone well in four weeks, the implantations was bony healed with host bone in eight weeks, and some of the implantations were replaced by new formation bone in 12 weeks. In histological examination of four week after operation, lamellar bone was found, and eight weeks after operation, implant was incorporated to host bone end by end through cortical bone, and new bone marrow was found to invade into the implant. Furthermore, the outer part of implant was completely substituted by new cortical bone 12 weeks after operation. In addition, the histological study pointed out that the new bone arranged in type of various bands which were in subsequent transition. There is significant difference between 4 weeks and 8 weeks, and 4weeks and 12 weeks, but no significant difference between 8 weeks and 12 weeks of the quantity of new bone.Conclusion:1. The compound of HA/TCP,BMP and bFGF possesses much high inductive potentialties and the ability of rebuilding bone defect.2. Since bFGF has positively inductive or stimulative effect on tissues, such as bone, cartilage, muscle, BMP combined with bFGF can apparently promotion effect on the repairing process of bone defect.3. The porous HA/TCP is a good scaffold material and can be used as bone substitutes clinically.4.Material degradation has close relation with the course of rebuilding bone defect,which is interactional.