Platelet‐Rich Fibrin Constructs Elute Higher Concentrations of Transforming Growth Factor‐β1 and Increase Tendon Cell Proliferation Over Time when Compared to Blood Clots: A Comparative In Vitro Analysis

Objective: To compare the concentration of a representative growth factor (transforming growth factor‐beta [TGF‐β]1) eluted from a platelet‐rich fibrin matrix (PRFMatrix), a platelet‐rich fibrin membrane (PRFMembrane), and a whole blood clot (BC) over time, and to compare the mitogenic effect of the eluents from each construct. Study Design: In vitro study. Sample Population: PRFMatrix, PRFMembrane, and BC (n=4/construct/time point). Methods: Each construct was placed in tissue culture wells containing media for 7 days. The media was collected and replenished on days 1, 3, 5, and 7 and the concentration of eluted TGF‐β1 was measured by enzyme‐linked immunosorbent assay. Canine tendon cells were subjected to additional aliquots of the conditioned media and the amount of cell proliferation compared. Results: The media from both PRFM (PRFMatrix and PRFMembrane) constructs contained significantly more (P≤.026) TGF‐β1 at days 1 and 3 and produced a significant increase (P≤.044) in cell proliferation at all time points compared with the BC. The PRFMembrane media contained significantly more (P≤.05) TGF‐β1 at days 1 and 3 and produced a significant increase (P≤.002) in cell proliferation at all time points compared with the PRFMatrix. Conclusions: Both PRFM constructs are comprised of a dense fibrin scaffold that contains increased concentrations of TGF‐β1 and are capable of increasing tendon cell proliferation over time when compared with a BC. Clinical Relevance: The sustained increase in growth factor availability in PRFM constructs may be beneficial in the healing of biologically compromised tissues.