Controlled Release of Fibroblast Growth Factor 2 Stimulates Bone Healing in an Animal Model of Diabetes Mellitus

Purpose: Bone formation and the healing of calvarial defects in mice is diminished in chemically induced type 1 diabetes. The present study investigated whether controlled local release of fibroblast growth factor 2 (FGF-2) stimulates bone defect healing in this model of diabetes. Materials and Methods: First, in vitro release kinetics of different doses of recombinant human FGF-2 (rhFGF-2) from polyglycolate:polylactide membranes was determined over a 14-day period by incubating loaded membranes in PBS with constant shaking. The amount of FGF-2 was measured by enzyme-linked immunosorbent assay. Then, the effects of rhFGF-2-loaded and control membranes on calvarial defect healing over a 14-day healing period were determined in diabetic and nondiabetic mice. The degree of healing was determined by histomorphometric analyses of bone area percentage and by area measurements. The significance of the data was determined by statistical analyses, including analysis of variance. Results: Kinetic release data in vitro showed that membranes loaded with 5 µg FGF-2 released measurable levels of growth factor for more than 14 days. Data from the in vivo study supported the previous finding that diabetes inhibits bone formation. Membranes containing rhFGF-2 significantly (P .05) stimulated bone formation in diabetic animals to near normal levels during the healing period. Conclusion: FGF-2-loaded membranes may be useful in further studies aimed at developing therapeutic strategies for correcting deficient bone healing in patients with diabetes. (More than 50 references) Keywords: bone regeneration, controlled release, diabetes, fibroblast growth factors, growth factors