Platelet-Rich Plasma Preparation Types Show Impact on Chondrogenic Differentiation, Migration, and Proliferation of XXXX Subchondral Mesenchymal Progenitor Cells.

@entity1 @entity558 @entity3669
PURPOSE: To evaluate the chondrogenic potential of platelet concentrates on @entity1 subchondral mesenchymal progenitor cells (MPCs) as assessed by histomorphometric analysis of proteoglycans and type II collagen. Furthermore, the migratory and proliferative effect of platelet concentrates were assessed. METHODS: Platelet-rich plasma (PRP) was prepared using preparation kits ( @entity558 [ @entity558 ] Kit [Arthrex, Naples, FL]; Regen ACR-C Kit [Regen Lab, Le Mont-Sur-Lausanne, Switzerland]; and Dr.PRP Kit [Rmedica, Seoul, Republic of Korea]) by apheresis (PRP-A) and by centrifugation ( @entity3669 ). In contrast to clinical application, freeze-and-thaw cycles were subsequently performed to activate platelets and to prevent medium coagulation by residual fibrinogen in  vitro. MPCs were harvested from the cortico-spongious bone of femoral heads. Chondrogenic differentiation of MPCs was induced in high-density pellet cultures and evaluated by histochemical staining of typical cartilage matrix components. Migration of MPCs was assessed using a chemotaxis assay, and proliferation activity was measured by DNA content. RESULTS: MPCs cultured in the presence of 5% @entity558 , Regen, or Dr.PRP formed fibrous tissue, whereas MPCs stimulated with 5% PRP-A or @entity3669 developed compact and dense cartilaginous tissue rich in type II collagen and proteoglycans. All platelet concentrates significantly ( @entity558 , P  = .00041; Regen, P  = .00029; Dr.PRP, P  = .00051; PRP-A, P < .0001; and @entity3669 , P < .0001) stimulated migration of MPCs. All platelet concentrates but one (Dr.PRP, P  = .63) showed a proliferative effect on MPCs, as shown by significant increases ( @entity558 , P  = .027; Regen, P  = .0029; PRP-A, P  = .00021; and @entity3669 , P  = .00069) in DNA content. CONCLUSIONS: Platelet concentrates obtained by different preparation methods exhibit different potentials to stimulate chondrogenic differentiation, migration, and proliferation of MPCs. Platelet concentrates obtained by commercially available preparation kits failed to induce chondrogenic differentiation of MPCs, whereas highly standardized PRP preparations did induce such differentiation. These findings suggest differing outcomes with PRP treatment in stem cell-based cartilage repair. CLINICAL RELEVANCE: Our findings may help to explain the variability of results in studies examining the use of PRP clinically.
