%A Ghanaati, Shahram %A Mourão, Carlos %A Adam, Elisabeth %A Sader, Robert %A Zadeh, Homayoun %A Al-Maawi, Sarah %T The role of centrifugation process in the preparation of therapeutic blood concentrates: Standardization of the protocols to improve reproducibility %9 Review Article %D 2019 %J International Journal of Growth Factors and Stem Cells in Dentistry %R 10.4103/GFSC.GFSC_15_19 %P 41-44 %V 2 %N 3 %U https://www.cellsindentistry.org/article.asp?issn=2589-7330;year=2019;volume=2;issue=3;spage=41;epage=44;aulast=Ghanaati %8 September 1, 2019 %X Investigations of endogenous blood-derived growth factors have increased in the past two decades. The initial protocols for blood concentrates, such as platelet-rich-plasma, utilized anticoagulants followed by bovine thrombin to catalyze fibrin polymerization. Subsequently, platelet-rich-fibrin (PRF) protocol was developed to eliminate anticoagulants and thrombin. The PRF production was described in a vertical rotor centrifuge with an angle of ~33°. Many commercial enterprises have attempted to replicate this protocol with a multitude of different centrifuges. These attempts have utilized revolutions per minute (RPM) to develop their protocol to generate PRF. However, RPM is a variable parameter, as it depends on the design and radius of the centrifuge. The separation of blood components is highly dependent on the relative centrifugal force (RCF) generated, which is based on the applied centrifugal force, expressed as multiples of earth's gravitation (g) field. RCF is a function of the acceleration due to the gravity of the earth, g = 9.81 m/s2 RCF, not RPM, is the key factor for the sedimentation of the cells and proteins within blood concentrates. RCF is determined using the maximum centrifuge radius for calculation. The initial PRF was generated by applying an RCF of 700 ×g. Accordingly, so far, a large number of studies existing about PRF are not comparable, as they were technically prepared with different RCFs. In addition, due to the nonstandardized measurement methods, in some published studies, incorrect RCF values are published as the authors did not know how to calculate the RCF correctly. This is the case for a widespread blood concentrate called leukocyte-PRF, which is commercially available. Recently, we introduced the low-speed centrifugation concept (LSCC) for the production for solid and liquid PRF matrices. This concept is based on the above-mentioned initial PRF protocols, which represents a relatively high RCF. It shows that a systematic reduction of 700 ×g to 44 ×g can significantly increase the cells and growth factors within the same blood concentrates. The LSCC concept was established initially for a fixed rotor centrifuge with a radius of ~110 mm. The present narrative review highlights the necessity of standardization in the generation of blood concentrates, which utilizes RCF, rather than commercial protocols. %0 Journal Article %I Wolters Kluwer Medknow Publications %@ 2589-7330