Background: Lipoaspirate centrifugation creates graded density of adipose tissue. High-density fat contains more vasculogenic cytokines and progenitor cells and has greater graft survival than low-density fat. The authors hypothesize that accelerating the bone marrow-derived progenitor cell response to injected low-density fat will improve its graft survival.
Methods: Male 8-week-old FVB mice (n=60) were grafted with either high-density (n=20) or low-density (n=40) human lipoaspirate. Half of the mice receiving low-density fat (n=20) were treated with a stem cell mobilizer for 14 days. Grafted fat was harvested at 2 and 10 weeks for analysis.
Results: Low-density fat, low-density fat plus daily AMD3100, and high-density fat had 26±3.0, 61.2±7.5, and 49.6±3.5 percent graft survival, respectively, at 2 weeks (low-density fat versus low-density fat plus daily AMD3100 and low-density fat versus high-density fat, both p<0.01). Similar results were observed 10 weeks after grafting. Mice receiving low-density fat plus daily AMD3100 had significantly more vasculogenic progenitor cells per cubic centimeter of peripheral blood (p<0.01) and more new blood vessels (p<0.01). Both low-density fat plus daily AMD3100 and high-density fat contained more stromal-derived factor-1α and vascular endothelial growth factor mRNA/protein.
Conclusion: Endogenous progenitor cell mobilization enhances low-density fat neovascularization, increases vasculogenic cytokine expression, and improves graft survival to a level equal to that of high-density fat grafts.