INTRODUCTION: Basic fibroblast growth factor (bFGF) is considered to enhance angiogenesis and to support bone formation in the presence of vital bone cells. Bone morphogenetic protein-2 (rhBMP-2) is known to induce bone formation. The aim of this study was to analyze the effect of bFGF and rhBMP-2 in the irradiated mandible. MATERIAL AND METHODS: The right mandibles of 24 rats were irradiated with a single dose of 20 Gy at a high-dose-rate (HDR) after loading machine (bio effective equivalent dose to ca. 45 x 2 Gy). After 12 weeks 100 microg rhBMP-2 (n=6 animals, group 1), 100 microg bFGF (n=6 animals, group 2) and 100 microg rhBMP-2 plus 100 microg bFGF (n=6 animals, group 3) were injected along the right mandible (left mandible: no irradiation, no growth factor). Another 6 animals (group 4) remained untreated after the irradiation. After another 7 weeks the specimens were examined by non-decalcified histology. RESULTS: Bone apposition of the experimental versus control sides was not statistically significantly different when one of the growth factors was applied alone (rhBMP-2: p=0.917; bFGF: p=0.345). Average bone apposition was significantly decreased on the experimental sides of group 3 (rhBMP-2+bFGF: p=0.046) and group 4 (p=0.008). Average bone densities were unaffected in all settings (for all p>0.1). CONCLUSIONS: The application of bFGF and the application of rhBMP-2 alone did result in predictable bone generation in the irradiated mandible with the bone apposition being equal to that of the non-irradiated side. The application of both growth factors together or none at all after irradiation results in significantly reduced bone apposition.
INTRODUCTION:Basic fibroblast growth factor (bFGF) is considered to enhance angiogenesis and to support bone formation in the presence of vital bone cells. Bone morphogenetic protein-2 (rhBMP-2) is known to induce bone formation. The aim of this study was to analyze the effect of bFGF and rhBMP-2 in the irradiated mandible. MATERIAL AND METHODS: The right mandibles of 24 rats were irradiated with a single dose of 20 Gy at a high-dose-rate (HDR) after loading machine (bio effective equivalent dose to ca. 45 x 2 Gy). After 12 weeks 100 microg rhBMP-2 (n=6 animals, group 1), 100 microg bFGF (n=6 animals, group 2) and 100 microg rhBMP-2 plus 100 microg bFGF (n=6 animals, group 3) were injected along the right mandible (left mandible: no irradiation, no growth factor). Another 6 animals (group 4) remained untreated after the irradiation. After another 7 weeks the specimens were examined by non-decalcified histology. RESULTS: Bone apposition of the experimental versus control sides was not statistically significantly different when one of the growth factors was applied alone (rhBMP-2: p=0.917; bFGF: p=0.345). Average bone apposition was significantly decreased on the experimental sides of group 3 (rhBMP-2+bFGF: p=0.046) and group 4 (p=0.008). Average bone densities were unaffected in all settings (for all p>0.1). CONCLUSIONS: The application of bFGF and the application of rhBMP-2 alone did result in predictable bone generation in the irradiated mandible with the bone apposition being equal to that of the non-irradiated side. The application of both growth factors together or none at all after irradiation results in significantly reduced bone apposition.
Authors: Sarvpreet Singh; Frank R Kloss; Regina Brunauer; Magdalena Schimke; Angelika Jamnig; Brigitte Greiderer-Kleinlercher; Günter Klima; Julia Rentenberger; Thomas Auberger; Oliver Hächl; Michael Rasse; Robert Gassner; Günter Lepperdinger Journal: J Cell Mol Med Date: 2012-04 Impact factor: 5.310