Rapid publication TGF-β1 induces bone closure of skull defects

Abstract
Transforming growth factor β1 (TGF-β1) is a multifunctional regulatory protein. It is capable of inducing site-specific healing responses by increasing collagen synthesis and deposition as well as remodeling at sites of soft tissue repair. Large bony defects in the skull heal by fibrous connective tissue and never form bone unless osteoinductive bony fragments or powders are placed in the defect. We have found, however, that the single application of human recombinant TGF-β1 in a simple 3% methylcellulose gel to skull defects induced a dose-dependent increase in intramembranous bone formation. Complete bony bridging of defects occurred within 28 days after treatment with 2 μg TGF-β1. Sites treated with vehicle alone did not heal with bone formation but rather contained dense fibrous connective tissue between the defect margins.