Platelet-Rich Fibrin Low-Speed Centrifugation Protocols and Particulate Bovine Bone on Bone Defects Repair

Platelet-rich fibrin (PRF) membranes and injectable PRF (i-PRF) are biological agents used to enhance healing, often combined with deproteinized bovine bone mineral (DBBM) for bone regeneration. This study evaluated low-speed centrifugation protocols for the preparation of PRF membranes and i-PRF combined with DBBM (sticky bone, SB) in repairing rat tibial bone defects. Sixty-four rats received tibial defects filled with blood clot (CO), PRF membrane alone (PRF), DBBM alone (BO), or i-PRF associated with DBBM (SB). Micro-computed tomography (μCT), histological analysis, and gene expression of molecular markers were assessed at 15 and 45 days. PRF membranes led to greater early bone formation and elevated Bglap expression compared to control (p < 0.05). μCT analysis showed that the BO group had significantly greater cortical bone formation at 15 days than the control group (p < 0.05). Additionally, both BO and SB groups promoted increased cortical bone formation at 45 days (p < 0.05), with SB also enhancing cortical thickness at the defect margins. In the medullary region, both BO and SB exhibited higher bone formation and trabecular number (p < 0.05) after 15 and 45 days. Gene expression analysis revealed higher levels of Alpl, Bglap, and Runx2 in the BO group than in SB and control groups (p < 0.05). In conclusion, PRF membranes improved early bone formation compared to a blood clot. DBBM, whether used alone or in combination with i-PRF, also enhanced bone regeneration compared to control. However, the addition of i-PRF did not improve the regenerative potential of DBBM.