Comprehensive evaluation of the antimicrobial properties of platelet-rich fibrin in vitro in the context of the oral microbiome and bacterial species diversity

Platelet-rich fibrin (PRF) is a platelet concentrate widely applied in various medical fields and is considered a valuable adjunct in tissue regeneration during surgical procedures. However, infections caused by biofilm-forming bacteria at surgical sites, combined with increasing antibiotic resistance, present a major clinical concern. Current research is focused on identifying alternative therapeutic strategies to improve infection control and promote wound healing. This study aimed to characterize the oral microbiome of healthy individuals and evaluate the in vitro antimicrobial properties of two PRF formulations. The antibacterial activity, along with its temporal dynamics at different initial bacterial concentrations, was assessed against Gram-negative bacteria ( Escherichia coli , Porphyromonas gingivalis ) and Gram-positive bacteria exhibiting diverse morphologies ( Bacillus subtilis , Micrococcus luteus , Staphylococcus lentus , Enterococcus casseliflavus , Streptococcus mutans ). Our results fill gaps in knowledge concerning the spectrum of PRF’s antimicrobial activity, demonstrating efficacy against a range of opportunistic and pathogenic bacteria. Key findings include the absence of significant differences in oral microbiome composition between male and female participants, a lack of inhibitory effect of A-PRF against S. mutans , and a transient inhibitory effect against P. gingivalis observed only at low initial OD₆₀₀ and within 24 hours. These results suggest that A-PRF therapy should be considered only in patients without active oral infection.