TRANSFORMING GROWTH-FACTOR-BETA ACCELERATES OSTEOINDUCTION IN A CRANIOFACIAL ONLAY MODEL

Recombinant human transforming growth factor beta1 was added to a demi neralized bone matrix (DBM) paste, formed into cylinders and implanted onto the cranial periosteum of New Zealand White rabbits, The TGF-bet a was added at doses of 0, 0.3, 3, 30 and 75 mug per implant. When the implants were removed after six weeks, histomorphometric analysis of the implants showed that TGF-beta induced significantly higher levels of trabecular bone formation than in the controls (mineralized bone ar ea 6.0 +/- 0.8, 6.0 +/- 1.2, 5.6 +/- 1.0, 10.1 +/- 1.5, and 10.8 +/- 1 .4 mm2, respectively, P<0.05). TGF-beta also caused greater resorption of the demineralized bone matrix carrier (matrix area 7.2 +/- 0.9, 6. 8 +/- 1.4, 3.7 +/- 0.9, 2.7 +/- 1.2, 0.9 +/- 0.5 mm2 , respectively, P <0.02). Measurements of the osteoid demonstrated a more active bone su rface and there was evidence of rapid bone remodeling. Similar results were obtained using TGF-5beta, a new hybrid molecule. These results d emonstrate the capacity of transforming growth factor beta in accelera ting osteoinduction.