Antibacterial Activity of Fresh and Autoclaved Platelet-Rich Fibrin on Pseudomonas aeruginosa: An In Vitro Study

Platelet-rich fibrin (PRF) is widely used in oral and maxillofacial procedures for its regenerative and antimicrobial properties. Structural modifications, such as autoclaving, may enhance its usability. This study compared the antibacterial effects of fresh and autoclaved PRF against Pseudomonas aeruginosa, a clinically relevant nosocomial pathogen.

PRF was prepared from six healthy volunteers. Fresh clots and autoclaved plasma fractions were tested using two centrifugation protocols. Antibacterial activity was assessed by disk diffusion and colony-forming unit (CFU) assays. Methanol extraction evaluated the contribution of heat-stable, non-protein components. Scanning electron microscopy (SEM) analyzed structural changes in PRF membranes following autoclaving.

Fresh PRF demonstrated antibacterial activity, with inhibition zones of 13.7 ± 0.6 mm (Protocol A) and 17.3 ± 0.8 mm (Protocol B), and significant CFU reduction. Autoclaved PRF showed slightly larger zones (15.2 ± 0.7 mm and 18.0 ± 0.6 mm) and enhanced efficacy (p < 0.0001), whereas methanol-extracted PRF retained partial activity. SEM revealed a dense fibrin network in fresh PRF and a porous, honeycomb-like architecture in autoclaved PRF, suggesting that structural changes may contribute to improved antibacterial function.

Both fresh and autoclaved PRF exhibited antibacterial activity against P. aeruginosa, with autoclaved PRF showing enhanced efficacy. Activity in methanol-extracted PRF indicates a potential role for heat-stable, non-protein components. These findings highlight thermally treated PRF as a sterilizable, bioactive biomaterial for infection-prone dental and surgical applications. Future studies should identify the specific antibacterial constituents and confirm their efficacy in vivo to support clinical translation.