Distribution, recovery and concentration of platelets and leukocytes in L-PRP prepared by centrifugation

Centrifugation Conditions in the L-PRP Preparation Affect Soluble Factors Release and Mesenchymal Stem Cell Proliferation in Fibrin Nanofibers

“…In previous work, we reported on the mechanisms of platelet and leukocyte recovery in L-PRP by centrifugation, which is driven by size, density, and erythrocyte aggregation and sedimentation [19]. As predicted by theoretical calculations and experimentally confirmed, low centrifugal accelerations in the first spin (50–100× g) contribute to high yields of platelets in P-PRP (upper layer) [45].…”

“…Whether conducted manually or by machine, L-PRP is prepared by centrifuging the patient’s whole blood, in which platelets, leukocytes, proteins, and other components are concentrated in a small fraction of plasma, with their levels adjusted by varying the centrifugation conditions [19,20]. In a previous study, we determined the distribution and recovery of platelets and leukocytes (lymphocytes and granulocytes) in the supernatant, buffy coat, and erythrocyte layers by centrifuging the whole blood from 100 to 800× g (10 min and 25 °C).…”

“…The concentration patterns allowed for the identification of specific centrifugation ranges to obtain distinct platelet/leukocyte and the associate lymphocyte/granulocyte ratios. As blood centrifugation is a separation process based on the size and density of the components as well as the packing behavior of the erythrocytes, different recoveries of platelets and leukocytes could be obtained in L-PRP from a first spin [19]. In turn, a second centrifugation step under accelerations higher than 400× g could lead to platelet aggregation and deactivation [20,21].…”

Letter to the editor: RE: Optimized platelet‐rich fibrin with the low‐speed concept: Growth factor release, biocompatibility, and cellular response

“…In the Materials and Methods section of the above‐mentioned article, L‐PRF is processed at 708 RCF (2,700 RPM in centrifuge, Table , Figure ), which is far above the standard protocol of the original L‐PRF (± 408 RCF) . This higher g‐force unfortunately has several negative side effects with significant impact on the outcome of the study: 1) a higher g force will push more cells to the bottom of the tube (Figure ) and as such reduces the cellular content in the clot, 2) at higher g force the PRF clot becomes poorer in platelets and leukocytes, and as such will release less growth factors, and 3) at higher g force, the radial vibration increases exponentially, which has a negative impact on the clot formation and its fibrin network, especially in a device that has already a high vibration by itself, and will definitely lead to cell damage, again leading to a reduced release of growth factors.…”

“…In the Materials and Methods section of the abovementioned article, L-PRF is processed at 708 RCF (2,700 RPM in centrifuge, Table 1, Figure 2), which is far above the standard protocol of the original L-PRF (± 408 RCF). 8,9 This higher g-force unfortunately has several negative side effects with significant impact on the outcome of the study: 1) a higher g force will push more cells to the bottom of the tube ( Figure 2) and as such reduces the cellular content in the clot, 10 2) at higher g force the PRF clot becomes poorer in platelets and leukocytes, and as such will release less growth factors, 11,12 and 3) at higher g force, the radial vibration increases exponentially, which has a negative impact on the clot formation and its fibrin network, 5 especially in a T A B L E 1 RCF calculation (minimum: RCF min , average: RCF av , maximum: RCF max , and RCF clot where clot is formed, respectively) for the 2 most frequently used centrifuges for the preparation of PRF: depending on the rotor angulation and the rotations per minute (RPM) device that has already a high vibration by itself, 5 and will definitely lead to cell damage, again leading to a reduced release of growth factors. These aspects might explain why A-PRF (in this paper prepared at 1,300 RPM, Table 1) showed an increase in growth factor release, and superior fibroblast migration, proliferation, and collagen mRNA levels in comparison to a misrepresented specimen of L-PRF ( Figure 2).…”