Study of platelet-rich fibrin promoting endothelial cell differentiation and angiogenesis induced by transplantation of adipose-derived stem cells

Diabetic patients are characterized by long wound healing time, and adipose stem cells (ADSCs) can secrete growth factors to promote angiogenesis and improve diabetic wound healing. In this research, we attempted to interrogate the impact of platelet-rich fibrin (PRF) on ADSCs in diabetic wound healing. ADSCs were harvested from human adipose tissues and identified through flow cytometry. After pretreatment with cultured medium supplemented with different concentrations of PRF (2.5%, 5%, and 7.5%), proliferation and differentiation capacity of ADSCs were assessed by CCK-8 assay, qRT-PCR and immunofluorescence (IF), respectively. Tube formation assay measured angiogenesis. Western blot analysis analyzed expression of endothelial markers and the extracellular signal-regulated kinase (ERK) and serine/threonine kinase (Akt) pathways in PRF-induced ADSCs. The CCK-8 experiment indicated that PRF enhanced proliferation of ADSCs in dose-dependent manner, relative to normal control group. The expression of endothelial markers and the capacity of tube formation were significantly promoted by 7.5% PRF. The release of growth factors containing vascular endothelial grow factor (VEGF) and insulin-like growth factor-1 (IGF-1) from PRF was increased with the extension of detection time. When the receptors of VEGF or/and IGF-1 were neutralized, ADSCs differentiation into endothelial cells were obviously inhibited. Additionally, PRF stimulated ERK and Akt pathways, and the inhibitors of ERK and Akt attenuated PRF-induced differentiation of ADSCs into endothelial cells. In conclusion, PRF promoted endothelial cell differentiation and angiogenesis induced by ADSCs in diabetic wound healing, which appears to give guidance for treating patients.