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

Platelet-rich plasma (PRP) is an autologous product prepared from whole blood (WB) that is widely used in regenerative medicine. In clinical practice, discontinuous centrifugation is used for both hand- and machine-prepared PRP. However, separation of WB fractions via centrifugation is a complex process, and the lack of clear mechanisms limits the understanding and evaluation of PRP preparation methods This paper focuses on the distribution, recovery and concentration factor of platelets and leukocytes in L-PRP (leukocyte and platelet-rich plasma) to define a concentration pattern for these blood components due to centrifugation conditions. WB collected from three healthy donors was centrifuged for 10min at 50-800 xg in a first step and then at 400 xg in a second step. The results from the first centrifugation step showed most platelets to be distributed in the upper layer (UL) and the buffy coat (BC), with approximately 14.5±5.2% retained in the bottom layer (BL). Most leukocytes were present in the BL. The greatest platelet recoveries from L-PRP were obtained at up to 150 xg (88.5±16.9%). The cumulative concentration factors with respect to the WB from the second centrifugation step were 6 and 1.2 for platelets and leukocytes, respectively. Thus, the concentration patterns delineated three centrifugation ranges with platelet/leukocyte ratios of 205±18, 325±15 and 107±4 and lymphocyte/granulocyte ratios of 1.54±0.74, 0.90±0.08 and 0.42±0.07. These findings contribute to a scientifically based standardization of L-PRP preparations.

Benefit of Leukocyte- and Platelet-Rich Plasma in Operative Wound Closure in Oral and Maxillofacial Surgery

This article reports the influence of an autologous leukocyte- and platelet-rich plasma (L-PRP) injection as a minimally invasive method on supporting wound healing processes after a mandibular odontogenic cystectomy and double mandibular fracture fixation. 113 patients were enrolled into a control group (received no L-PRP injection) and 102 patients were enrolled into an L-PRP group with an oral mucosa incision. 18 patients after a double mandibular fracture were operated on using 2 external submandibular approaches receiving no fluids in the right site (a control group) and an L-PRP injection in the left incision (L-PRP group). Clinical observations showed that the oral mucosa healed faster in patients treated with L-PRP, in comparison to cases where inductive biomaterial was not added. Pain at the L-PRP injection site was relieved within few hours after an operation in patients with double mandibular fractures. However, there were no differences observed in the progression of the healing process. L-PRP possesses inductive properties that could stimulate healing processes and it seems to be one of the most promising methods in the future for the treatment of soft tissue defects.