The impact and in vitro mechanisms of frozen stored platelet-rich plasma on wound repair
Objective To evaluate the effects and mechanisms of frozen-thawed platelet-rich plasma(PRP)stored at-80 ℃ on wound healing-related cells.Furthermore,to explore the feasibility and effectiveness of using cryopre-served PRP at low temperatures for promoting wound healing.Methods Using non-activated fresh PRP,calcium-activated fresh PRP,and post-thawed PRP,co-cultured with macrophages,fibroblasts,and vascular endothelial cells,the study measured and compared the expression of polarization and inflammatory factors associated with macropha-ges,as well as cell migration and proliferation rates,among other indicators,to analyze the effects of PRP on macro-phage polarization,inflammation,and cell proliferation.Results Compared with the control group,post-cryopre-served PRP at ultra-low temperatures resulted in decreased expression of M1-like polarized macrophage gene iNOS(P<0.000 1),reduced NO secretion(P<0.001),increased urea content(P<0.000 1),decreased M1-related inflammatory factor tumor necrosis factor-alpha(TNF-α)(P<0.001),and decreased secretion of white blood cell interleukin(IL)-1(P<0.001);M2-related anti-inflammatory factor IL-10 secretion levels increased(P<0.01),and IL-12 secretion increased(P<0.05)Furthermore,co-culturing with frozen-thawed PRP significantly promoted cell migration and enhanced vascular formation efficiency,surpassing the effects of fresh PRP and being comparable to activated PRP(P<0.01).Cell viability assays and CCK-8 proliferation experiments also showed a significant in-crease in the proliferation rates of L929 and HUVEC co-cultured with frozen-thawed PRP(P<0.01).Conclusion After being cryopreserved at-80 ℃,PRP has been proven to significantly enhance cell migration,differentia-tion,and proliferation capabilities,while inhibiting the production of inflammatory factors and promoting M2 polari-zation of macrophages.Therefore,low-temperature cryopreservation can be considered as an effective method for PRP preservation.