[Effects of Platelet-Rich Plasma on Macrophage Phenotype and Its Influencing Factors]

To evaluate the effects of platelet-rich plasma (PRP) supernatants with different activation methods and storage time on human monocyte-derived macrophages phenotype and explore the possible mechanism.

Human monocyte-derived macrophages were cultured in vitro with PRP or activated PRP supernatants activated with different activators. The expression of marker molecules on the surface of macrophages was detected by flow cytometry, and the concentration of growth factors in PRP supernatants was detected by ELISA.

After 24 h of coculture, the expression level of CD86 in macrophages stimulated by PRP supernatant (thrombin and Cacl₂ activated) was significantly higher than that by PRP group (P<0.05), and the expression of CD163 in macrophages was increased by Cacl₂ activated PRP supernatant. Compared with different activator groups, the expression of CD163 in macrophages of Cacl₂ activated group was significantly higher than that of thrombin and ADP groups (P<0.05). ELISA results showed that the concentrations of FGF (P<0.001) and EGF (P<0.05) in the supernatant of PRP stored at -80 ℃ for more than 20 months and 10-20 months were significantly higher than those in the group stored at less than 10 months after Cacl₂ activation, and the expressions of CD86 (P<0.01), CD163 (P<0.001) and CD206 (P<0.001) in macrophages cocultured with the supernatant of the two groups were significantly increased.

PRP activated by different activators has different effects on the phenotype of macrophages. Meanwhile, the storage time will also affect the growth factor concentration and effect of PRP.