Prefabrication of Vascularized Allogenic Bone Graft in a Rat by Implanting a Flow-Through Vascular Pedicle and Basic Fibroblast Growth Factor Containing Hydroxyapatite/Collagen Composite

Background Basic fibroblast growth factor (bFGF) is known to stimulate bone formation and angiogenesis. Hydroxyapatite/collagen composite (HAp/Col) is also known to have very strong bone conductive activity. In this study, prefabrication of vascularized allogenic bone (alto-bone) graft was attempted in recipients by implanting vascular bundles from recipients into the transplanted alto-bone graft. Furthermore, the effect of bFGF-containing HAp/Col on the prefabricated vascularized allo-bone graft was investigated. Methods In this study, 32 Sprague-Dawley rats were used as donors, and bone grafts were collected from their femora. Thirty-two Wistar rats (recipients) were divided into four groups, and the alto-bone grafts were transplanted into the thigh region. In the experimental groups, one or both of the flow-through saphenous vascular bundles and 100-pg bFGF-containing HAp/Col were implanted into the medullary cavity of the allobone grafts. In the control group, neither was implanted. These rats were sacrificed at 4 weeks after transplantation, and bone formation, angiogenesis, and bone resorption in the transplanted allo-bone grafts were evaluated histologically and genetically. Results Bone formation and angiogenesis in the transplanted alto-bone graft were effectively stimulated by implanting vascular bundles or bFGF-containing HAp/Col on both histological and genetic evaluations compared with the control group. The most significant stimulation was observed in the group in which both were implanted. Bone resorption was not stimulated in any group. Conclusion By implanting a flow-through vascular bundle and bFGF-containing HAp/Col, an ideal vascularized alto-bone graft that had high bone formative and angiogenetic activities and did not stimulate bone resorptive activity was prefabricated.