Effect of Reduced Centrifugation Time on Leukocyte, Platelet, and Growth Factor Levels in Platelet-Rich Fibrin (PRF) Prepared Using Low-Speed Relative Centrifugal Force (RCF): An Ex Vivo Study

TL;DR

Shortening centrifugation time from 8 to 4 minutes improves the concentration of leukocytes, platelets, and growth factors in PRF, potentially enhancing its regenerative properties for periodontal applications.

Contribution

The study demonstrates that reducing centrifugation time improves cellular and growth factor yields in PRF, offering a more efficient protocol for clinical use.

Findings

Reducing centrifugation time to 4 minutes significantly increased leukocyte and platelet concentrations.

VEGF levels showed a near-significant rise, while TGF-β exhibited a non-significant upward trend.

The shorter protocol suggests improved cellular retention and growth factor release.

Abstract

Background: Platelet-rich fibrin (PRF), a second-generation autologous biomaterial, enhances periodontal regeneration through its fibrin matrix, which is enriched with leukocytes, platelets, and growth factors such as vascular endothelial growth factor (VEGF) and transforming growth factor-beta (TGF-β). Centrifugation parameters critically influence the regenerative composition of PRF, with low-speed relative centrifugal force (RCF) protocols improving both cellular and molecular yields. However, the impact of centrifugation time remains underexplored. This study investigates whether reducing centrifugation time from 8 to 4 minutes at 44 g (600 rpm) optimizes PRF’s regenerative profile for periodontal applications.

Methods: Peripheral blood from 10 healthy male volunteers (aged 20-30 years) reporting to a tertiary care center was processed into fluid PRF using two protocols: 8-minute and 4-minute centrifugation at 600 rpm. Leukocyte and platelet concentrations were quantified via flow cytometry, while VEGF and TGF-β levels were measured using enzyme-linked immunosorbent assay (ELISA) at 1 and 24 hours post-clotting. The Wilcoxon signed-rank test assessed differences between protocols (p ≤ 0.05).

Results: Reducing centrifugation time to 4 minutes significantly increased leukocyte (median: 0.04-0.07 ×10³ cells/µL, p = 0.008) and platelet (median: 578-691 ×10³ cells/µL, p = 0.005) concentrations. VEGF levels showed a near-significant rise (median: 4.19-6.10 pg/mL, p = 0.051), while TGF-β exhibited a non-significant upward trend (median: 35.57-36.43 ng/mL, p = 0.594). These enhancements suggest improved cellular retention and growth factor release.

Conclusion: A 4-minute centrifugation at 600 rpm suggests improved cellular retention and trends toward higher growth factor concentrations by enhancing leukocyte, platelet, and VEGF concentrations, with a modest TGF-β increase. This protocol offers potential biochemical enhancement with improved chair-side efficiency, warranting further clinical validation.

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