Platelet-rich fibrin increases cell attachment, proliferation and collagen-related protein expression of human osteoblasts

Background: Platelet-rich fibrin (PRF) prepared by Choukroun's technique is derived from an autogenous preparation of concentrated platelets without any manipulation. PRF was found to increase osteoblast growth and proliferation. However, the underlying mechanisms are not yet completely understood. This study aimed to determine the effects of PRF on cell attachment, proliferation, phosphorylated Akt, heat shock protein 47 (HSP47) and lysyl oxidase (LOX) expression on human osteoblasts. Methods: Blood collection was carried out from 10 healthy volunteers. Cell attachment and proliferation were measured by colorimetric assay with WST-1 and alamar blue in human osteoblast cell line U2OS cells, respectively. Western blot was employed to evaluate the expression of p-Akt, HSP47 and LOX. Results: PRF alone was found to stimulate U2OS cell attachment compared with untreated controls (p < 0.05). PRF was found to increase osteoblast proliferation during a 5-day incubation period (p < 0.05). PRF was found to increase Akt phosphorylation in a time-dependent manner (p < 0.05). Collagen-related proteins HSP47 and LOX were significantly elevated by stimulation with PRF compared with untreated controls (p < 0.05). Conclusions: It is suggested that PRF is capable of increasing osteoblast attachment, proliferation and simultaneously upregulating collagen-related protein production. These actions in combination would effectively promote bone regeneration.