An in vitro comparison of PDGF‐BB release from composite graft materials containing leukocyte‐rich platelet‐rich fibrin and platelet‐derived growth factor‐BB and β‐tricalcium phosphate

Background

The clinical efficacy of growth factors in regenerative procedures may depend on both dosage and sustained delivery during critical phases of healing. This study aimed to evaluate in vitro release kinetics of platelet‐derived growth factor‐BB (PDGF‐BB) from various graft materials, including recombinant human PDGF‐BB (rhPDGF‐BB) combined with beta‐tricalcium phosphate (β‐TCP), leukocyte platelet‐rich fibrin (L‐PRF) with β‐TCP (PRF bone block), L‐PRF bone block with added rhPDGF‐BB, and L‐PRF membranes alone.

Methods

Whole blood samples were collected from five healthy adult donors. L‐PRF membranes and autologous liquid fibrinogen were prepared according to manufacturer's protocols. Five samples of each of the following were prepared: L‐PRF membranes, L‐PRF + β‐TCP with or without rhPDGF‐BB, and β‐TCP + rhPDGF‐BB. All materials were incubated at 37°C, and 2 mL aliquots of supernatant were collected at 1 hour, 8 hours, 1 day, 3 days, and 10 days. PDGF‐BB concentrations were quantified using enzyme‐linked immunosorbent assay (ELISA), and data were analyzed using a linear mixed effects model with Tukey's post hoc test.

Results

Significantly higher PDGF‐BB concentrations were observed in samples containing rhPDGF‐BB at all‐time points. Further, the L‐PRF + rhPDGF‐BB + β‐TCP group demonstrated a gradual and sustained release from 1 hour to 10 days. In contrast, the rhPDGF‐BB + β‐TCP group showed an early peak followed by minimal release after day 3.

Conclusion

The incorporation of L‐PRF into β‐TCP scaffolds containing rhPDGF‐BB resulted in prolonged and more controlled PDGF‐BB release. Composite graft formulation may maintain growth factor availability during early and intermediate phases of healing.

Plain language summary

This study was designed to determine how different materials release a healing protein, PDGF‐BB, over time. This protein helps tissues regenerate, and its effectiveness depends on both how much is delivered and how long it stays active during healing. Four combinations of composite graft materials were tested using blood from healthy donors: (1) laboratory‐produced version PDGF‐BB with a synthetic hard tissue graft (β‐TCP), (2) autologous blood product (L‐PRF) with β‐TCP, (3) L‐PRF with β‐TCP plus added laboratory‐produced PDGF‐BB, and (4) L‐PRF alone.

PDGF‐BB release was measured at different times over 10 days. Composite grafts with added laboratory‐produced PDGF‐BB released more of the protein overall. The combination of L‐PRF, β‐TCP, and synthetic PDGF‐BB released the protein slowly and steadily over time. The synthetic PDGF‐BB with β‐TCP alone released a lot early on, but very little after day 3.

Based upon these findings and within the limitation of this study, use of composite grafts containing L‐PRF with β‐TCP and laboratory‐produced PDGF‐BB may help improve healing by keeping the growth factor available longer during the most important stages of tissue repair. Further clinical studies are necessary to determine the comparative clinical benefits of such composite grafts.