In Vitro Evaluation of the Regenerative Potential of Autologous Platelet-Rich Fibrin (PRF) on Human Primary Periodontal Ligament Cells

Periodontitis is a prevalent condition that leads to the destruction of periodontal tissue, making the regeneration of the periodontium a key focus in dental research. In this context, periodontal ligament cells (PDLCs) are particularly interesting due to their stem cell-like properties, including the ability to differentiate into various cell types and further contribute to tissue repair. This study aimed to isolate and characterize primary human PDLCs and examine the effects of both indirect and direct treatment with the blood concentrate platelet-rich fibrin (PRF), with particular focus on how PRF influences cell proliferation and differentiation. PDLCs were treated with PRF prepared using a low relative centrifugal force (600 rpm) either directly through a conditioned medium or indirectly using trans-well filter systems. The impact of PRF on PDLC proliferation and differentiation was assessed through viability assays, alkaline phosphatase assays, gene and protein expression analyses, and immunofluorescence. PDLCs exhibited cellular markers characteristic of stem cell-like cells. In addition, PRF treatment was found to suppress cell proliferation while concurrently promoting osteogenic differentiation and increase factors important for tissue regeneration. These effects were more pronounced when the cells were directly treated with PRF-conditioned medium compared to indirect treatment. Our findings support the hypothesis that PRF serves as a biologically active reservoir of growth factors that modulate PDLC behavior and might create a microenvironment favorable for periodontal repair.