Alternative sources of mesenchymal stem cells (MSCs) for replacing bone marrow (BM) have been extensively investigated in the field of bone tissue engineering. The purpose of this study was to compare the osteogenic potential of canine MSCs derived from adipose tissue (AT), BM, umbilical cord blood (UCB), and Wharton's jelly (WJ) using in vitro culture techniques and in vivo orthotopic implantation assays. After canine MSCs were isolated from various tissues, the proliferation and osteogenic potential along with vascular endothelial growth factor (VEGF) production were measured and compared in vitro. For the in vivo assay, MSCs derived from each type of tissue were mixed with beta-tricalcium phosphate and implanted into segmental bone defects in dogs. Among the different types of MSCs, AT-MSCs had a higher proliferation potential and BM-MSCs produced the most VEGF. AT-MSCs and UCB-MSCs showed greater in vitro osteogenic potential compared to the other cells. Radiographic and histological analyses showed that all tested MSCs had similar osteogenic capacities, and the level of new bone formation was much higher with implants containing MSCs than cell-free implants. These results indicate that AT-MSCs, UCB-MSCs, and WJ-MSCs can potentially be used in place of BM-MSCs for clinical bone engineering procedures.
Adipocytes, White/cytology/physiology ; Alkaline Phosphatase/metabolism ; Animals ; Biocompatible Materials/metabolism/*therapeutic use ; Bone Diseases/*therapy ; Bone Marrow Cells/cytology/physiology ; Calcification, Physiologic ; Calcium/metabolism ; Calcium Phosphates/metabolism/therapeutic use ; Cell Proliferation ; Dogs ; Female ; Fetal Blood/cytology/physiology ; Flow Cytometry ; Male ; Mesenchymal Stromal Cells/cytology/*metabolism ; *Osteogenesis ; Polyesters/metabolism/therapeutic use ; Tissue Engineering/*methods ; Vascular Endothelial Growth Factor A/metabolism