Rabbit Tibial Periosteum and Saphenous Arteriovenous Vascular Bundle as an In Vivo Bioreactor to Construct Vascularized Tissue‐Engineered Bone: A Feasibility Study

The aim of this project was to construct vascularized tissue‐engineered living bone with an autologous vascular network by means of a rabbit bioreactor in vivo. The key components of the in vivo bioreactor for bone formation were the vascularized tibial periosteum and the saphenous vascular bundle. Beta‐tricalcium phosphate (β‐TCP) scaffolds were implanted into the in vivo bioreactor (vascular pedicle implantation and vascularized periosteum encapsulation). At 4 weeks postsurgery, new bone formation was mainly “cartilage‐bone inducing” in the inner periosteum, and was primarily seen in the outer aspects of the scaffold with some amount in the middle part as well. Microvascular infusion showed that direct revascularization of β‐TCP was obtained by means of vascular implantation. Triple staining results showed a large amount of blue collagen fibers. Vascular endothelial growth factor immunohistochemical staining displayed endothelial cells of new blood vessels in bone tissue. The bioreactor established in this study can be used to prepare tissue‐engineered bone with a vascular network.