Prefabricated Vascularized Bone Graft Using Autologous Tissue, Biomaterials, and Growth Factors: A New Technique for Bone Reconstruction

Although clinically, grafting of vascularized autologous bone has been preferably performed, there are some disadvantages for this grafting therapy, such as the limited availability of donor site and the clinical difficulty to harvest the bone graft of desired shape and size. As one trial, we have designed a prefabricated vascularized bone graft by combining autologous vessels, particulate cancellous bone and marrow (PCBM), and β-tricalcium phosphate (β-TCP) with a biodegradable membrane. However, the volume of vascularized bone tissue newly formed was small and the density was low. In this study, the controlled system of basic fibroblast growth factor (bFGF) was combined with the conventional preparation method to improve the nature of vascularized bone graft. The femur vessels of rabbits were rolled with a membrane of L-lactide-ε-caploractone copolymer. Hydrogel microspheres of gelatin were prepared as the release carrier of bFGF. Autologous PCBM harvested from the beforehand tibia of rabbits was mixed with β-TCP granules with or without the microspheres incorporating bFGF and packed into the rolled membrane. When bone formation was assessed at different time intervals, additional mixing of bFGF significantly increased the volume of vascularized bone tissue compared to that without bFGF. It is concluded that combination of bFGF release system was a promising method to prefabricate the bone graft of large size with good blood circulation.