摘要
Objective To evaluate the effect of transforming growth factor β/bone morphogenetic protein (TGF β/BMP) composite on the healing of large segmental bone defects and to discuss the interaction between TGF β and BMP during bone repair. Methods A 1.5 cm segmental defect was made in the mid upper part of the radial shaft of 48 adult rabbits. The defects were filled with implants of TGF β/carrier, BMP/carrier or TGF β/BMP/carrier separately. 120 μg of purified bovine TGF β and 12 mg of BMP were used in the composite. The defects were examined radiographically and histologically at 4, 8, 12 and 16 weeks post operation. Results In the group filled with TGF β/BMP composite, the defect areas were bridged at 4 weeks, with callus of uniform radiodensity. Cortices of the cut ends were obscured by new bone. By 16 weeks post operation, the defects were bridged by uniform new bone and the cut ends of the cortex could not be seen in all groups. In group of BMP/carrier, the defects were filled with more irregular woven bone callus than in other two groups. TGF β/BMP implanted defects in animals killed at 16 weeks showed histologically new lamella and woven bone that was formed in continuity with the cut ends of the cortex. Medullar canal was recanalized and contained marrow elements with normal appearance. Conclusions These data demonstrate not only the synergistic action between TGF β and BMP in the process of bone healing, but also a better effect of TGF β/BMP composite than single TGF β or BMP on bone repair, especially in the early stage of bone repair process.
Objective To evaluate the effect of transforming growth factor β/bone morphogenetic protein (TGF β/BMP) composite on the healing of large segmental bone defects and to discuss the interaction between TGF β and BMP during bone repair. Methods A 1.5 cm segmental defect was made in the mid upper part of the radial shaft of 48 adult rabbits. The defects were filled with implants of TGF β/carrier, BMP/carrier or TGF β/BMP/carrier separately. 120 μg of purified bovine TGF β and 12 mg of BMP were used in the composite. The defects were examined radiographically and histologically at 4, 8, 12 and 16 weeks post operation. Results In the group filled with TGF β/BMP composite, the defect areas were bridged at 4 weeks, with callus of uniform radiodensity. Cortices of the cut ends were obscured by new bone. By 16 weeks post operation, the defects were bridged by uniform new bone and the cut ends of the cortex could not be seen in all groups. In group of BMP/carrier, the defects were filled with more irregular woven bone callus than in other two groups. TGF β/BMP implanted defects in animals killed at 16 weeks showed histologically new lamella and woven bone that was formed in continuity with the cut ends of the cortex. Medullar canal was recanalized and contained marrow elements with normal appearance. Conclusions These data demonstrate not only the synergistic action between TGF β and BMP in the process of bone healing, but also a better effect of TGF β/BMP composite than single TGF β or BMP on bone repair, especially in the early stage of bone repair process.
