Platelet-rich fibrin suppresses in vitro osteoclastogenesis

Platelet-rich fibrin (PRF) membranes can preserve alveolar ridge dimension after tooth extraction. Thus, it can be presumed that PRF suppresses the catabolic events that are caused by osteoclastic bone resorption.

To address this possibility, we investigated the impact of soluble extracts of PRF membranes on in vitro osteoclastogenesis in murine bone marrow cultures. Osteoclastogenesis was induced by exposing murine bone marrow cultures to receptor activator of nuclear factor kappa B ligand (RANKL), macrophage colony-stimulating factor (M-CSF) and transforming growth factor-beta 1 (TGF-β1) in the presence or absence of PRF. Osteoclastogenesis was evaluated based on histochemical, gene expression, and resorption analysis. Viability was confirmed by formation of formazan crystals, live-dead staining and caspase-3 activity assay.

We report here that in vitro osteoclastogenesis is greatly suppressed by soluble extracts of PRF membranes as indicated by tartrate-resistant acid phosphatase (TRAP) staining and pit formation. In support of the histochemical observations, soluble extracts of PRF membranes decreased expression levels of the osteoclast marker genes TRAP, Cathepsin K, dendritic cell-specific transmembrane protein (DCSTAMP), nuclear factor of activated T-cells (NFATc1), and osteoclast-associated receptor (OSCAR). PRF membranes, however, cannot reverse the process once osteoclastogenesis has evolved.

These in vitro findings indicate that PRF membranes can inhibit the formation of osteoclasts from hematopoietic progenitors in bone marrow cultures. Overall, our results imply that the favorable effects of PRF membranes in alveolar ridge preservation may be attributed, at least in part, by the inhibition of osteoclastogenesis.