The effect of a fibrin-fibronectin/β-tricalcium phosphate/recombinant human bone morphogenetic protein-2 system on bone formation in rat calvarial defects

In spite of good prospects for bone morphogenetic proteins (BMP) applications, an ideal carrier system for BMPs has not yet been identified. The purpose of this study was to evaluate the osteogenic effect of a fibrin-fibronectin sealing system (FFSS) combined with β-tricalcium phosphate (β-TCP) as a carrier system for recombinant human bone morphogenetic proteins (rhBMP-2) in the rat calvarial defect model.Eight-millimeter critical-size calvarial defects were created in 100 male Sprague–Dawley rats. The animals were divided into five groups of 20 animals each. The defects were treated with rhBMP-2/FFSS, rhBMP-2/FFSS/β-TCP, FFSS and FFSS/β-TCP carrier control or were left untreated as a sham-surgery control. Defects were evaluated by histologic and histometric parameters following a 2- and 8-week healing interval (10 animals/group/healing intervals).The FFSS/β  -TCP carrier group was significantly greater in new bone area at 2 weeks (p<0.05p<0.05) and new tissue area at 2 and 8 weeks (p<0.01p<0.01) relative to the FFSS carrier group. New bone and new tissue area in the rhBMP-2/FFSS/β  -TCP group were significantly greater than in the rhBMP-2/FFSS group at 8 weeks (p<0.01p<0.01). On histologic observation, FFSS remnants were observed at 2 weeks, but by 8 weeks, the FFSS appeared to be completely resorbed. rhBMP-2 combined with FFSS/β-TCP produced significantly more new bone and new tissue formation in this calvarial defect model. In conclusion, FFSS/β-TCP may be considered as an available carrier for rhBMP-2.