Which of the following promotes osteogenesis in grafts?

Growth differentiation factor-5 (GDF-5) plays a significant role in promoting osteogenesis, particularly in the context of grafts. It is a member of the transforming growth factor-beta (TGF-β) superfamily and is involved in the regulation of cartilage and bone development. GDF-5 functions by stimulating the proliferation and differentiation of bone progenitor cells, ultimately leading to the formation of new bone tissue. Its ability to promote osteogenesis makes it a valuable factor in regenerative medicine and in the context of grafting, where bone healing and integration are critical.

While strengthening agents, collagen fibers, and hydroxyapatite have their own roles within the biological framework and structural support in grafts, they do not directly induce osteogenesis to the extent that GDF-5 does. Strengthening agents primarily focus on providing mechanical stability, collagen fibers serve as a scaffold for cells but do not inherently stimulate bone formation, and hydroxyapatite acts as a inorganic component that mimics bone mineral, aiding in the overall structure but not in the active process of osteogenesis. Thus, GDF-5 is specifically recognized for its direct stimulation of bone cell activity and creation of bone tissue, which is essential for successful graft integration and healing.