Growth factor and cell content in Platelet-Rich Plasma (PRP), Leukocyte- and Platelet-Rich Plasma (L-PRP), Platelet-Rich Fibrin (PRF) in patients with long bone defects from combat injuries.

BACKGROUND: In contemporary regenerative medicine, platelet concentrates (PCs) are actively used as a promising method to support the regenerative process. However, the lack of standardized preparation protocols and the selection of PC types limits their broad clinical implementation, particularly in patients with non-unions or bone defects. Therefore, the aim of this study was to determine the concentration of platelets, leukocytes, and growth factors such as vascular endothelial growth factor (VEGF-A), transforming growth factor beta (TGF-β1), platelet-derived growth factor (PDGF-BB) in three types of PC, such as platelet-rich plasma (PRP), leukocyte- and platelet-rich plasma (L-PRP), platelet-rich fibrin (PRF) using a single donor model in patients with large bone defects after combat trauma compared to healthy individuals. METHODS: Blood for PRP, L-PRP and PRF was collected from 30 participants. 19 healthy volunteers and 11 patients with long bone defects after combat injuries. For the production of three types of PC, 15 ml of blood was taken from each participant. The cellular composition was determined using an automated hematological analyzer. The concentration of growth factors VEGF-A, TGF-β1, PDGF-BB was determined by ELISA. RESULTS: Differences in cellular composition and growth factor concentration between PC types were identified in all study participants. The concentration of platelets in PCs was distributed as follows: L-PRP > PRP > PRF; however, this did not affect the concentration of growth factors. The concentration of growth factors in PCs from patients with bone defects did not differ from that of healthy individuals. In patients with bone defects, it was not possible to achieve an enrichment of leukocyte concentration in L-PRP compared to the baseline level of whole blood; however, this parameter did not differ from that of healthy individuals. CONCLUSIONS: Growth factor concentrations were similar in patients and healthy individuals, but patients had differences in L-PRP leukocyte enrichment and lower platelet recovery in PRF. This study highlights the need to consider platelet concentrate characteristics when selecting products for regenerative therapy. CLINICAL TRIAL NUMBER: Not applicable.