Consideration of bone regeneration effect of stem cells: comparison between adipose-derived stem cells and demineralized bone matrix.

Background: Currently, many studies have sought to address the regeneration of extensive bone defects using stem cells. Here, the authors injected adipose-derived stem cells and demineralized bone matrix (DBM) into areas of bone defect in rabbits and compared their effect on bone regeneration to study the clinical usefulness of stem cells.

Methods: This study used 20 male New Zealand white rabbits. Four craniectomies were made in 20 male New Zealand white rabbits' calvaria, and 4 different groups of experimental conditions were applied to each of the 4 cranial defects. To the first group, 0.2 mL of DBX, a commercially available clinical preparation ofDBM, was applied with fibrin glue. To the second group, 0.2 mL of adipose-derived stem cells, with confirmed bone differentiation ability, was applied with fibrin glue. To the third group, 0.1 mL of DBX, 0.1 mL of adipose-derived stem cells, and fibrin glue were applied. The fourth group of defects acted as the control and was left unaltered. After 6 weeks, regenerated bone from each defect site in each rabbit was collected and measured for volume change. Bone regeneration was assessed with three-dimensional skull bone computed tomography and histological analysis.

Results: Osteoblasts were confirmed in all defect groups after 6 weeks. Overall, bone regeneration was weakest in the control group, whereas other groups of defects showed distinct bone regeneration. In particular, group 3, to which adipose-derived stem cells and DBM were applied, demonstrated the most active regeneration.

Conclusions: Both adipose-derived stem cells and DBM demonstrated regeneration effect on cranial defects in rabbits, but it is difficult to conclude which was better, because in each case the amount of regenerated bone was within the margin of error. However, as the most active bone regeneration was observed when both adipose-derived stem cells and DBM were applied together, this combination could be helpful in the correction of extensive bone defects.