Advanced Platelet-Rich Fibrin: A New Concept for Cell-Based Tissue Engineering by Means of Inflammatory Cells

TLDR

PRF is produced from blood without anticoagulants, and neutrophils facilitate monocyte‑to‑macrophage differentiation, a key step in tissue repair. The study compares S‑PRF (2700 rpm, 12 min) and A‑PRF (1500 rpm, 14 min) protocols to determine how centrifugation parameters influence cell distribution for wound healing, and seeks to validate this tissue‑engineering concept in vivo. Four donor clots were generated under the two protocols and immunohistochemically stained for monocytes, T/B lymphocytes, neutrophils, CD34+ stem cells, and platelets. A‑PRF produced a higher distal platelet and neutrophil density, while both groups had lymphocytes, stem cells, and monocytes near the buffy coat; the increased neutrophil presence in A‑PRF may enhance macrophage differentiation and support bone and soft‑tissue regeneration.

Abstract

Choukroun's platelet-rich fibrin (PRF) is obtained from blood without adding anticoagulants. In this study, protocols for standard platelet-rich fibrin (S-PRF) (2700 rpm, 12 minutes) and advanced platelet-rich fibrin (A-PRF) (1500 rpm, 14 minutes) were compared to establish by histological cell detection and histomorphometrical measurement of cell distribution the effects of the centrifugal force (speed and time) on the distribution of cells relevant for wound healing and tissue regeneration. Immunohistochemistry for monocytes, T and B -lymphocytes, neutrophilic granulocytes, CD34-positive stem cells, and platelets was performed on clots produced from four different human donors. Platelets were detected throughout the clot in both groups, although in the A-PRF group, more platelets were found in the distal part, away from the buffy coat (BC). T- and B-lymphocytes, stem cells, and monocytes were detected in the surroundings of the BC in both groups. Decreasing the rpm while increasing the centrifugation time in the A-PRF group gave an enhanced presence of neutrophilic granulocytes in the distal part of the clot. In the S-PRF group, neutrophils were found mostly at the red blood cell (RBC)-BC interface. Neutrophilic granulocytes contribute to monocyte differentiation into macrophages. Accordingly, a higher presence of these cells might be able to influence the differentiation of host macrophages and macrophages within the clot after implantation. Thus, A-PRF might influence bone and soft tissue regeneration, especially through the presence of monocytes/macrophages and their growth factors. The relevance and feasibility of this tissue-engineering concept have to be proven through in vivo studies.