Induction of new bone by ceramic bovine bone with recombinant human bone morphogenetic protein 2 and transforming growth factor beta.

Bone morphogenetic protein (BMP) has the ability to induce ectopic bone, while the action of transforming growth factor beta (TGF beta) is to stimulate proliferation of osteoblasts and chondrocytes as well as the production of extracellular matrix. The aim of the present study was to study their synergistic actions in bone formation. Three kinds of complexes, recombinant human BMP2 (rhBMP2), TGF beta and rhBMP2/TGF beta in ceramic bovine bone (CBB), were made and then implanted into the thigh muscle pouches of mice. The histological reactions of the implanted areas were studied at intervals of 3, 5, 7, 14 and 21 days. The results showed that, except for the implants with TGF beta alone, both rhBMP2 and rhBMP2/TGF beta implants exhibited new ectopic bone formation. The morphometric study revealed that the quantity of newly formed bone induced by rhBMP2/TGF beta was obviously greater than by rhBMP2 alone. These results indicate that TGF beta in combination with BMP may enhance formation of ectopic bone.