Background: Adipose-derived stem cells can improve fat graft survival, but there is no literature reporting whether bone marrow-derived mesenchymal stem cells enhance fat graft survival. The authors explored the feasibility of enhancing fat graft survival using bone marrow-derived mesenchymal stem cells.
Methods: Third-passage expanded rabbit bone marrow-derived mesenchymal stem cells were characterized by adipocyte and osteocyte differentiation and by CD29 and CD31 expression. Three were three groups of nude mice in this experiment: group A, mesenchymal stem cells; group B, expanded mesenchymal stem cells; group C, Dulbecco's medium as a blank control. The transplanted mixture contained 0.3 ml of adipose granule and 0.2 ml of cell components of 5×10⁶ cells. Four months later, grafts were harvested, weighed, and analyzed.
Results: Expanded cells were successfully isolated and identified by fibroblast-like adherent shape and osteogenic and adipogenic differentiation. The results were 24.6±3.4 percent for CD29 and 1.8±0.4 percent for CD31 in group A, and 45.0±4.9 percent for CD29 and 1.6±0.3 percent for CD31 in group B. Fat graft survival rates were 0.2052±0.0015 g, 0.1761±0.0014 g, and 0.1350±0.0020 g in groups A, B, and C, respectively (p<0.05). Fat grafts in group A exhibited the best survival and morphologic integrity, uniform lipid droplets, and rich blood vessels; those in group B exhibited modest survival, less integrity, less uniform lipid droplets, and connective tissue septa; and those in group C exhibited some large bubbles, varied sizes of lipid droplets, and significant fibrous septa (p<0.05). The vascular densities for groups A, B, and C were 30.4±1.5, 27.2±1.3, and 23.3±1.9 capillaries/mm2, respectively (p<0.05).
Conclusions: Bone marrow-derived mesenchymal stem cells and expanded bone marrow-derived mesenchymal stem cells are capable of improving fat graft survival; bone marrow-derived mesenchymal stem cells are more potent than expanded bone marrow-derived mesenchymal stem cells for doing so.