Effect of storage temperature and time on growth factor concentration in single-harvest platelet-rich plasma

Based on its therapeutic potential, the Platelet-rich plasma (PRP) therapy doubled in interest. Storage of this blood product in appropriate conditions allows for many interventions and increased clinical use. This research was intended to determine how the change in the storage temperature and time affects the concentrations of the essential growth factors of the PRP, which determines its biological activity.

PRP was prepared from 10 healthy donors and stored at room temperature (RT; 22°C), 4°C, and -65°C. Aliquots were analyzed at baseline (0 days), 1, 3, and 6 days post-preparation. Growth factors platelet-derived growth factor-AA (PDGF-AA), transforming growth factor-β (TGF-β), vascular endothelial growth factor (VEGF), and fibroblast growth factor-basic (b-FGF) were quantified after activation using Triton-X (PDGF-AA, VEGF, b-FGF) or sonication (TGF-β1), with sandwich immunoassays.

PDGF-AA concentrations consistently declined over time across all storage conditions. In contrast, TGF-β1 levels progressively increased, reaching peak concentrations by day 6. VEGF exhibited a reduction in samples stored at RT and -65 °C, while b-FGF concentrations dropped sharply after 24 h in these same groups. Refrigeration (4 °C) showed intermediate effects on growth factor stability compared to other temperatures.

Growth factor concentrations in PRP varied significantly depending on the activation technique, with no difference in activators for the same growth factor. These findings underscore the importance of optimizing storage protocols to preserve PRP's bioactive properties. For clinical efficacy, PRP should be activated and stored under conditions that maintain growth factor integrity, ensuring maximal therapeutic benefit.