CONTINUOUS ADMINISTRATION OF BASIC FIBROBLAST-GROWTH-FACTOR (FGF-2) ACCELERATES BONE INDUCTION ON RAT CALVARIA - AN APPLICATION OF A NEW DRUG-DELIVERY SYSTEM

Some studies have shown that locally applied basic fibroblast growth f actor (FGF-2) enhances bone regeneration at a fracture site, while oth ers have not been in agreement. We developed a new continuous FGF-2 de livery system designed to accelerate cytokine-induced new bone formati on. A subperiosteal pocket was surgically formed in 36 eight-week-old male Wistar rats. The rats were administered 0, 1, 10, or 100 ng of FG F-2 contained in a collagen minipellet, mixed with allogeneic deminera lized bone matrix in a dome-shaped Millipore(R) filter and then placed into the pocket. New bone formation in the dome was evaluated at 2, 4 , and 8 wks after placement. Soft x-ray radiographs disclosed an appar ently larger radiopaque region in the l-ng group at 4 wks compared wit h those in the other groups. Morphometrical analysis revealed that the new bone area in the l-g group was significantly larger than that in the 0-g group (p < 0.01). In the 100-ng FGF-2 group, new bone formatio n seemed suppressed. We concluded that continuous slow administration of a small amount of FGF-2 accelerates bone-derived osteogenic cytokin e-induced new bone formation.