Engineering a vascularized bone tissue construct via transgenic angiogenic induction

Abstract

Stromal cell-derived factor 1á (SDF-1á) serves as chemoattractant that direct the migration of stem cells such as hematopoietic stem cells and mesenchymal stem cells (MSCs) to the injury site, where the level of SDF-1á is increased. This SDF-1á-induced migration of MSCs are necessary for tissue regeneration. For example, SDF-1á promotes bone healing by recruiting the MSCs to the bone injury site. Besides, the increase in the SDF-1á level will also recruit endothelial progenitor cells (EPCs) that will promote vascularization, which is a crucial step in bone formation. In this study, we transfected the living hyaline cartilage graft (LhCG) with adenoviral vector that contain SDF-1á transgene to forcefully express the transgenic chemoattractant, SDF-1á. We attempted to study the role of SDF-1á in bone formation. The LhCG constructs were cultured in different medium, such as osteogenic (OG) medium, chondrocytes culture (CC) medium and MCDB. The results indicated that the LhCG construct cultured in OG medium highly express the Col I and Col X, followed by MCDB and CC medium. These 2 collagens are the biomarkers for bone formation. With the supply of OG medium, enhanced bone formation was observed.