Comparison of cell number, viability, phenotypic profile, clonogenic, and proliferative potential of adipose-derived stem cell populations between centrifuged and noncentrifuged fat

Autologous fat grafting is a widely adopted surgical technique in both the reconstructive and aesthetic fields. This study aimed to compare centrifuged lipoaspirates harvested and refined by the Coleman technique with noncentrifuged lipoaspirates in terms of cell number and viability, phenotypic profile, and clonogenic and proliferative potential of adipose-derived stem cell (ADSC) populations. For each patient, both a centrifuged sample using the Coleman's technique and a noncentrifuged sample of adipose tissue were collected. Adipose-derived stem cells from both the centrifuged fraction (CF) and the noncentrifuged fraction (NCF) were isolated. The recovered ADSCs were used to set up flow cytometry analysis, colony-forming units-fibroblast (CFU-F) assays, and ADSC cultures. The number of recovered cells was variable among the different donors but significantly higher in the CF donors. Cell viability, determined by the Trypan Blue dye assay, always exceeded 95 %, in both the CF and NCF fractions. Analysis of the putative ADSC subpopulations showed a significant enrichment of the mesenchymal and endothelial progenitors in CF compared with NCF. No differences in the clonogenic efficiency of the ADSC samples were observed when the same number of cells were plated from each fraction. On the contrary, when equal fat volumes were compared, the colony-forming ability of CF was always significantly higher than that of its NCF counterparts. This is the first study to comprehensively characterize the impact of Coleman's technique on the quality of lipoaspirates, showing that centrifugation is safe and feasible and does not impair cell viability, can augment the content in ADSC and the frequency of CFU-F, and reduces the number of proinflammatory blood cells.