Osteogenic and Angiogenic Potency of VEGF165-Transfected Canine Bone Marrow Mesenchymal Cells Combined with Coral Hydroxyapatite in Vitro

To explore the osteogenic and angiogenic potential of human vascular endothelial growth factor 165 (hVEGF165) gene-transfected canine bone marrow mesenchymal stem cells (BMSCs) combined with coral hydroxyapatite (CHA) scaffold. We constructed a lentiviral vector and transfected canine BMSCs with the best multiplicity of infection. Osteogenesis was induced in the transfected groups (GFP-BMSCs group and hVEGF-BMSCs group) and non-transfected group (BMSCs group), followed by the evaluation of alkaline phosphatase (ALP) activity and alizarin red S staining. Cells from the three groups were co-cultured with CHA granules, respectively to obtain the tissue-engineered bone. MTT assay and fluorescence microscopy were employed to assess cell proliferation and adhesion. The expression of osteogenic and angiogenic related genes and proteins were evaluated at 7, 14, 21, and 28 days post osteoinduction in cell culture alone and cell co-culture with CHA, respectively using RT-PCR and ELISA. The hVEGF165 gene was transfected into BMSCs successfully. Higher ALP activity and more calcified nodules were found in the hVEGF-BMSCs group than in the control groups (p < 0.001). Cells attached and proliferated in CHA particles. Both cells cultured alone and cells co-culture with CHA expressed more osteogenic and angiogenic related genes and proteins in the hVEGF-BMSCs group compared to the GFP-BMSCs and BMSCs groups (p < 0.05). High expression of hVEGF165 in BMSCs potentially promote the osteogenic potential of BMSCs, and synergically drive the expression of other osteogenic and angiogenic factors. hVEGF-BMSCs co-cultured with CHA expressed more osteogenic and angiogenic related factors, creating a favorable microenvironment for osteogenesis and angiogenesis. Also, the findings have allowed for the construction of a CHA-hVEGF-BMSCs tissue-engineered bone.