TRANSFORMING GROWTH-FACTOR-BETA-1 IN A GUANIDINE-EXTRACTED DEMINERALIZED BONE-MATRIX CARRIER RAPIDLY CLOSES A RABBIT CRITICAL CALVARIAL DEFECT

Transforming growth factor beta 1 (TGF-beta 1) is a polyfunctional reg ulatory cytokine that has been shown to have roles in extracellular ma trix interactions, soft tissue healing, and osteogenesis. Twenty-five mu L of recombinant human TGF-beta 1 was added to a guanidine-extracte d demineralized bone matrix carrier and the implants were used to fill a 14-mm osteoperiosteal critical calvarial defect in a New Zealand wh ite rabbit model. The defects were allowed to heal over 4 weeks and th e degree of new bone formation was assessed by radiodensitometry and u ndecalcified bone histomorphometry techniques. Implants with TGF-beta 1 showed complete bridging of the gap with new bone in all cases, whil e the controls showed fibrous tissue repair of the gap with little or no new bone formation. These results demonstrate the ability of TGF-be ta 1 to induce new bone in a brief time period in an inactive carrier.