title: Heparin concentration is critical for cell culture with human platelet lysate.
abstract: OBJECTIVE
  Culture media for mesenchymal stromal cells (MSCs) are generally supplemented with fetal bovine serum. Human platelet lysate (hPL) has been proven to be a very effective alternative without the risk of xenogeneic infections or immune reactions. In contrast to fetal bovine serum, hPL comprises plasma, and anticoagulants-usually unfractionated heparin (UFH)-need to be added to prevent gel formation.
  
  
  METHODS
  Cultures of MSCs in hPL media with various concentrations of UFH and enoxaparin, a low-molecular-weight heparin (LMWH), were systematically compared with regard to proliferation, fibroblastoid colony-forming unit frequency, immunophenotype and in vitro differentiation.
  
  
  RESULTS
  At least 0.61 IU/mL UFH or 0.024 mg/mL LMWH was necessary for reliable prevention of coagulation of hPL pools used in this study. Higher concentrations impaired cellular proliferation in a dose-dependent manner even without benzyl alcohol, which is commonly added to heparins as a bacteriostatic agent. Colony-forming unit frequency was also reduced at higher heparin concentrations, particularly with LMWH, whereas no significant effect was observed on cellular morphology or immunophenotype. High concentrations of heparins reduced the in vitro differentiation toward adipogenic and osteogenic lineages.
  
  
  CONCLUSIONS
  Heparin concentration is critical for culture of MSCs in hPL media; this is of particular relevance for cellular therapy where cell culture procedures need to be optimized and standardized.
authors.affiliation: Helmholtz-Institute for Biomedical Engineering, RWTH Aachen University Medical School, Aachen, Germany.
authors.forename: Hatim
authors.initials: H
authors.lastname: Hemeda
authors.forename: Jana
authors.initials: J
authors.lastname: Kalz
authors.forename: Gudrun
authors.initials: G
authors.lastname: Walenda
authors.forename: Michael
authors.initials: M
authors.lastname: Lohmann
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Wagner
mesh_terms: D050156:Adipogenesis / Q000187:drug effects; D001792:Blood Platelets / Q000378:metabolism*; D002454:Cell Differentiation / Q000187:drug effects; D002457:Cell Extracts / Q000494:pharmacology*; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured / Q000187:drug effects*; D003470:Culture Media / Q000378:metabolism*; D006493:Heparin / Q000494:pharmacology*; D006801:Humans; D016130:Immunophenotyping / Q000379:methods; D059630:Mesenchymal Stem Cells / Q000187:drug effects; D010012:Osteogenesis / Q000187:drug effects
chemical_list: D002457:Cell Extracts; D003470:Culture Media; D006493:Heparin
keywords: differentiation; fetal bovine serum; fibroblasts; human platelet lysate; mesenchymal stromal cells; platelet lysate gel; proliferation; serum