Gelatin hydrogel as a carrier of recombinant human fibroblast growth factor-2 during rat mandibular distraction.

The aim of the present study was to evaluate the feasibility of a gelatin hydrogel system to enhance recombinant human fibroblast growth factor-2 (rhFGF-2)-induced osteogenic effects during rat mandibular distraction. Mandibular distraction was performed in 28 male Wistar rats. Then, the rats were divided into 5 groups in which the designated gel mix was inserted into the distracted area: group 1, rhFGF-2 alone (n = 5); group 2, collagen alone (n = 6); group 3, collagen incorporating rhFGF-2 (n = 6); group 4, gelatin hydrogel alone (n = 5); and group 5, gelatin hydrogel incorporating rhFGF-2 (n = 6). The mandibles were excised 29 days after surgery and the newly formed bone was analyzed radiologically and histologically. The experimental groups were compared using the Fisher post hoc test (95% statistical significance threshold; P < .05). Peripheral quantitative computed tomographic analysis, von Kossa staining, and calcein staining showed that using gelatin hydrogel with rhFGF-2 (group 5) significantly increased cortical bone mineral density, the domain area of hard tissue, the domain area of cortical bone area, total bone mineral content, cortical bone mineral content, the von Kossa-stained area, and the calcein-stained area compared with the collagen carrier (group 3). Group 5 also had a significantly larger number of cells positive for tartrate-resistant acid phosphatase compared with group 3 and radiopaque areas were observed more frequently. The present findings suggest that gelatin hydrogel is a feasible delivery system for rhFGF-2, and when used together perform better in regard to hard tissue healing and treatment time after surgery.