title: Reduction of relative centrifugation force within injectable platelet-rich-fibrin (PRF) concentrates advances patients' own inflammatory cells, platelets and growth factors: the first introduction to the low speed centrifugation concept.
abstract: OBJECTIVE
  The aim of this study was to analyze systematically the influence of the relative centrifugation force (RCF) on leukocytes, platelets and growth factor release within fluid platelet-rich fibrin matrices (PRF).
  
  
  METHODS
  Systematically using peripheral blood from six healthy volunteers, the RCF was reduced four times for each of the three experimental protocols (I-III) within the spectrum (710-44 g), while maintaining a constant centrifugation time. Flow cytometry was applied to determine the platelets and leukocyte number. The growth factor concentration was quantified 1 and 24 h after clotting using ELISA.
  
  
  RESULTS
  Reducing RCF in accordance with protocol-II (177 g) led to a significantly higher platelets and leukocytes numbers compared to protocol-I (710 g). Protocol-III (44 g) showed a highly significant increase of leukocytes and platelets number in comparison to -I and -II. The growth factors' concentration of VEGF and TGF-β1 was significantly higher in protocol-II compared to -I, whereas protocol-III exhibited significantly higher growth factor concentration compared to protocols-I and -II. These findings were observed among 1 and 24 h after clotting, as well as the accumulated growth factor concentration over 24 h.
  
  
  CONCLUSIONS
  Based on the results, it has been demonstrated that it is possible to enrich PRF-based fluid matrices with leukocytes, platelets and growth factors by means of a single alteration of the centrifugation settings within the clinical routine.
  
  
  CONCLUSIONS
  We postulate that the so-called low speed centrifugation concept (LSCC) selectively enriches leukocytes, platelets and growth factors within fluid PRF-based matrices. Further studies are needed to evaluate the effect of cell and growth factor enrichment on wound healing and tissue regeneration while comparing blood concentrates gained by high and low RCF.
authors.affiliation: Private Practice, Pain Therapy Center, Nice, France. joseph@a-prf.com.|Department for Oral, Cranio-Maxillofacial and Facial Plastic Surgery, FORM (Frankfurt Orofacial Regenerative Medicine) Laboratory, University Hospital Frankfurt Goethe University, Theodor-Stern-Kai 7, 60590, Frankfurt am Main, Germany. joseph@a-prf.com.
authors.forename: J
authors.initials: J
authors.lastname: Choukroun
authors.affiliation: Department for Oral, Cranio-Maxillofacial and Facial Plastic Surgery, FORM (Frankfurt Orofacial Regenerative Medicine) Laboratory, University Hospital Frankfurt Goethe University, Theodor-Stern-Kai 7, 60590, Frankfurt am Main, Germany. shahram.ghanaati@kgu.de.
authors.forename: S
authors.initials: S
authors.lastname: Ghanaati
mesh_terms: D000328:Adult; D055359:Antistatic Agents; D001792:Blood Platelets / Q000378:metabolism*; D002498:Centrifugation / Q000379:methods*; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism*; D007962:Leukocytes / Q000378:metabolism*; D000073183:Platelet-Rich Fibrin / Q000166:cytology* / Q000502:physiology
chemical_list: D055359:Antistatic Agents; D036341:Intercellular Signaling Peptides and Proteins
keywords: A-PRF+; Centrifugation; I-PRF; Inflammation; Leukocytes; Pain; Platelet-rich fibrin; Platelets; Tissue engineering