Fig. 4. Detection of growth factors. (A) Expression levels of platelet-derived growth factor AB (PDGF AB), vascular endothelial growth factor receptor 2 (VEGF R2), transforming growth factor-β (TGF-β), and epidermal growth factor (EGF) were evaluated in fresh platelet-rich plasma (PRP) according to the intensity of the spots. The location of each is shown in the scheme. (B) PRP was stored at room tempertature for 8 weeks, and all growth factor expressions were almost undetectable. (C) Frozen PRP was stored for 8 weeks, after which faint expression of growth factors was observed. (D) The freeze-dried PRP was stored for 8 weeks, and almost all growth factors were expressed robustly.
