Objective To investigate and compare the osteogenic potential of three kinds of calcium phosphate ceramic as carriers for recombinant human bone morphogenetic protein-2(rhBMP-2) in vivo.Methods BCPceramics (HA,TCP,HA/TCP) impregnated with rhBMP-2 (experimental groups) and without rhBMP-2(control groups) were implanted into 6 muscles pockets on the dorsum of 3month-old Wistar rabbits. The rabbits were sacrificed 2, 4 and 8 weeks after implantation and bone induction was estimated by alkaline phosphatase(ALP) activity measurement. The implants were also examined histologically and histomorphometrically by HE staining and computerized graphical analysis. Results The ALPactivity of implants withrhBMP-2 was higher than that of control groups(P＜0.05), but there was no difference between 2 and 4 weeks in experimental groups. In all experimental groups,theimplants exhibited that new bone formation increased with the lapse of time. The amount of new bone formation is more in -HA/rhBMP-2 group than in the other two group in the 2nd and 4th weeks, but there was no difference between them (P＞0.05).In the 8th week, the amount of bone formation was most in HA/TCP with -rhBMP-2, and was more than that in the 2nd and 4th weeks. Whereas in control groups, there was only fibrous connective tissue. Conclusion HA/TCP- is a good carriers of rhBMP-2 and can be used as bone substitutes clinically.
Abstract To examine the effects of porous tricalcium phosphate (TCP) combined with autogenous red bone marrow (BM) in therepar of bone defects, 21 cases of bone defects were implanted with the above prepared composite material, 17 cases had benign or low-grade malignant tumors and 4cases had old fractures. Serial X-ray films were taken after surgery. The results showed that new bone formation was seen between the interface of the implantand surrounding host bone after 6 weeks, and osseous union developed after 12 weeks. Evident osteogenesis in all patients was observed after a follow-up for 1～3 years. TCP-BM is both osteoconductive and osteoinductive. Its function was similar to the fresh autogenous cancellous bone graft and TCP-BM had the potencyof promoting the repair of osseous defect. It was suggested that TCP-BM might be an ideal material for treating bone defects.