title: Platelet-Rich Plasma Preparation Types Show Impact on Chondrogenic Differentiation, Migration, and Proliferation of Human Subchondral Mesenchymal Progenitor Cells.
abstract: OBJECTIVE
  To evaluate the chondrogenic potential of platelet concentrates on human 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 (Autologous Conditioned Plasma [ACP] 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 (PRP-C). 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% ACP, Regen, or Dr.PRP formed fibrous tissue, whereas MPCs stimulated with 5% PRP-A or PRP-C developed compact and dense cartilaginous tissue rich in type II collagen and proteoglycans. All platelet concentrates significantly (ACP, P = .00041; Regen, P = .00029; Dr.PRP, P = .00051; PRP-A, P < .0001; and PRP-C, 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 (ACP, P = .027; Regen, P = .0029; PRP-A, P = .00021; and PRP-C, 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.
  
  
  CONCLUSIONS
  Our findings may help to explain the variability of results in studies examining the use of PRP clinically.
authors.affiliation: Department of Orthopaedic Surgery, University Medical Center Rostock, Rostock, Germany.
authors.forename: Peter Cornelius
authors.initials: PC
authors.lastname: Kreuz
authors.affiliation: TransTissue Technologies, Berlin, Germany.
authors.forename: Jan Philipp
authors.initials: JP
authors.lastname: Krüger
authors.affiliation: Department of Orthopaedic and Trauma Surgery, Martin-Luther Krankenhaus, Berlin, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Metzlaff
authors.affiliation: TransTissue Technologies, Berlin, Germany.
authors.forename: Undine
authors.initials: U
authors.lastname: Freymann
authors.affiliation: TransTissue Technologies, Berlin, Germany.
authors.forename: Michaela
authors.initials: M
authors.lastname: Endres
authors.affiliation: Department of Transfusion Medicine, Charité-Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Axel
authors.initials: A
authors.lastname: Pruss
authors.affiliation: Department of Orthopaedic and Trauma Surgery, Martin-Luther Krankenhaus, Berlin, Germany.
authors.forename: Wolf
authors.initials: W
authors.lastname: Petersen
authors.affiliation: TransTissue Technologies, Berlin, Germany. Electronic address: christian.kaps@transtissue.com.
authors.forename: Christian
authors.initials: C
authors.lastname: Kaps
mesh_terms: D001792:Blood Platelets / Q000502:physiology; D002356:Cartilage / Q000166:cytology; D002454:Cell Differentiation; D002465:Cell Movement; D002478:Cells, Cultured; D019902:Chondrocytes / Q000502:physiology*; D024043:Collagen Type II / Q000378:metabolism*; D006801:Humans; D064235:Matrilin Proteins / Q000378:metabolism; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000502:physiology*; D053657:Platelet-Rich Plasma; D011509:Proteoglycans / Q000378:metabolism*; D056910:Republic of Korea
chemical_list: D024043:Collagen Type II; D064235:Matrilin Proteins; D011509:Proteoglycans