Transplantation of Cbfa1-Overexpressing Adipose Stem Cells Together with Vascularized Periosteal Flaps Repair Segmental Bone Defects

Abstract

Segmental bone defect is still a challenge to orthopedic surgeons. Currently available therapies for segmental bone defects have some drawbacks. Tissue engineering using pluripotent stem cells is a new, promising method for bone repair. The present study aims to promote the effect of bone defect repair using the tissue engineered bone in combination with vascularized periosteal flaps. The adenoviral vector carrying Cbfa1 transduced rabbit adipose-derived mesenchymal stem cells and gene modified tissue engineering bone (GMB) were constructed. Rabbits with radial defects were implanted with the GMB together with vascularized periosteum (group A); or GMB with free periosteum (group B); or GMB (group C), and scaffold (group D). The bone repair effect was evaluated at 4, 8, or 12 wk, respectively, after the operations. Cbfa1 proteins were strongly expressed in adipose stem cells (ADSCs) that formed a stratified network on the inner surface of the polylactic acid/ polycaprolacton (PLA/PCL) pores. Bone repair was well achieved in the rabbits treated with the Cbfa1-expressing ADSCs and vascularized flap that was markedly better than those treated with either Cbfa1-expressing ADSCs alone or with vascularized flap alone. Combination with implanting the Cbfa1 gene-modified tissue-engineered bone and vascularized periosteum can better repair the segmental bone defects by stimulating osteogenesis, osteoinduction, and osteoconduction than using either one of the approaches.