Plasma rich in growth factors (PRGF) and leukocyte-platelet rich fibrin (L-PRF): comparative release of growth factors and biological effect on osteoblasts

PURPOSE: To compare the release of platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), insulin-like growth factor (IGF-I) and interleukin 1β (IL-1β) of plasma rich in growth factors (PRGF) and leucocyte platelet-rich fibrin (L-PRF) and to evaluate their biological implication in osteoblasts. METHODS: Blood from 3 healthy volunteers was processed into PRGF, immediate L-PRF (L-PRF 0ʹ) and L-PRF 30 min after collection (L-PRF-30ʹ) and a control group. Growth factors release were analyzed at 7 times by ELISA. Cell proliferation, collagen-I synthesis and alkaline phosphatase activity were assessed in primary cultures of human osteoblasts. RESULTS: A slower controlled release of IGF-I, VEGF and PDGF was observed in the PRGF group at day 14. A higher synthesis of type I collagen was also quantified in PRGF. L-PRF released significantly higher amounts of IL-1β, that was almost absent in the PRGF. CONCLUSIONS: The addition of leukocytes dramatically increases the secretion of proinflammatory cytokines, which are likely to negatively influence the synthesis of type I collagen and alkaline phosphatase (ALP) by osteoblasts.