Abstract: Objective To evaluate the efficacy of rehydration solutions prepared in different ingredients on freeze-dried platelet-rich plasma（FD-PRP）activation and release of growth factors. Methods The experiments were divided into four groups: control group, platelet-poor plasma（PPP）; group 1, saline solution; group 2, ultrapure water; group 3, phosphate-buffered saline（PBS）buffer according to the difference between rehydration solutions. After rehydrated FD-PRP with four rehydration solutions, the contents of CD63, P-Selectin, transforming growth factor-beta 1（TGF-β1）, vascular endothelial growth factor（VEGF）, platelet-derived growth factor-BB（PDGF-BB）and basic fibroblast growth factor（bFGF）were determined by ELISA. Results While P-Selectin and CD63 expression in saline group, ultrapure water group and PBS buffer group were slightly higher than those in PPP group, there was no significant difference. The levels of growth factors in other three rehydration solutions were lower than those in PPP group. There was no significant difference in other four growth factors levels between other three groups and PPP group, except for the statistically significant difference in insulin-like growth factor-I（IGF-I）. Conclusion Normal saline is widely available and safe. As a rehydration solution, it had little impact on freeze-dried platelet activation. The levels of growth factors had no significant difference compared to PPP rehydration solution. It can be used as a routine rehydration solution for FD-PRP.

Key words: Platelet-rich plasma, Rehydration solution, Freeze-dried Growth, factors