Platelet-Rich Plasma Influences Expansion and Paracrine Function of Adipose-Derived Stromal Cells in a Dose-Dependent Fashion

BACKGROUND: Lipofilling is a treatment modality to restore tissue volume. Both platelet-rich plasma and adipose-derived stromal cells have been reported to augment the efficacy of lipofilling, yet results are not conclusive. The authors hypothesized that the variation reported in literature is caused by a dose-dependent influence of platelet-rich plasma on adipose-derived stromal cells. METHODS: Whole blood (n = 3) was used to generate platelet-rich plasma, which was diluted with Dulbecco's Modified Eagle Medium to 15%, 5%, and 1.7%, with 15% platelet-poor plasma and 10% fetal calf serum as controls. Pooled adipose-derived stromal cells (n = 3) were cultured in these media. Gene expression was assessed, along with angiogenic sprouting of endothelial cells by conditioned medium and platelet-rich plasma. RESULTS: platelet-rich plasma in culture medium affected the expression of genes in a dose-dependent manner. The 15% concentration stimulated proliferation almost eightfold. Mesenchymal markers were unaffected. Interestingly, expression of collagens type 1 and 3 increased at lower concentrations, whereas transforming growth factor-β showed reduced expression in lower concentrations. Proangiogenic gene expression was unaltered or strongly reduced in a dose-dependent manner. platelet-rich plasma promoted endothelial sprouting and survival in a dose-dependent manner; however, conditioned medium from adipose-derived stromal cells exposed to platelet-rich plasma blocked endothelial sprouting capabilities. CONCLUSION: The dose-dependent influence of platelet-rich plasma on the therapeutic capacity of adipose-derived stromal cells conditioned medium in vitro warrants caution in clinical trials.