title: Multipotent mesenchymal stromal cells from amniotic fluid: solid perspectives for clinical application.
abstract: BACKGROUND
  Mesenchymal stromal cells are multipotent cells considered to be of great promise for use in regenerative medicine. However, the cell dose may be a critical factor in many clinical conditions and the yield resulting from the ex vivo expansion of mesenchymal stromal cells derived from bone marrow may be insufficient. Thus, alternative sources of mesenchymal stromal cells need to be explored. In this study, mesenchymal stromal cells were successfully isolated from second trimester amniotic fluid and analyzed for chromosomal stability to validate their safety for potential utilization as a cell therapy product.
  
  
  METHODS
  Mesenchymal stromal cells were expanded up to the sixth passage starting from amniotic fluid using different culture conditions to optimize large-scale production.
  
  
  RESULTS
  The highest number of mesenchymal stromal cells derived from amniotic fluid was reached at a low plating density; in these conditions the expansion of mesenchymal stromal cells from amniotic fluid was significantly greater than that of adult bone marrow-derived mesenchymal stromal cells. Mesenchymal stromal cells from amniotic fluid represent a relatively homogeneous population of immature cells with immunosuppressive properties and extensive proliferative potential. Despite their high proliferative capacity in culture, we did not observe any karyotypic abnormalities or transformation potential in vitro nor any tumorigenic effect in vivo.
  
  
  CONCLUSIONS
  Fetal mesenchymal stromal cells can be extensively expanded from amniotic fluid, showing no karyotypic abnormalities or transformation potential in vitro and no tumorigenic effect in vivo. They represent a relatively homogeneous population of immature mesenchymal stromal cells with long telomeres, immunosuppressive properties and extensive proliferative potential. Our results indicate that amniotic fluid represents a rich source of mesenchymal stromal cells suitable for banking to be used when large amounts of cells are required.
authors.affiliation: Centro Cellule Staminali e Terapia Cellulare, Ospedale San Martino, L.go R. Benzi 10, 16132 Genova Italy.
authors.forename: Nadia
authors.initials: N
authors.lastname: Sessarego
authors.forename: Alessia
authors.initials: A
authors.lastname: Parodi
authors.forename: Marina
authors.initials: M
authors.lastname: Podestà
authors.forename: Federica
authors.initials: F
authors.lastname: Benvenuto
authors.forename: Massimo
authors.initials: M
authors.lastname: Mogni
authors.forename: Valentina
authors.initials: V
authors.lastname: Raviolo
authors.forename: Mario
authors.initials: M
authors.lastname: Lituania
authors.forename: Annalisa
authors.initials: A
authors.lastname: Kunkl
authors.forename: Guido
authors.initials: G
authors.lastname: Ferlazzo
authors.forename: Franca Dagna
authors.initials: FD
authors.lastname: Bricarelli
authors.forename: Antonio
authors.initials: A
authors.lastname: Uccelli
authors.forename: Francesco
authors.initials: F
authors.lastname: Frassoni
mesh_terms: D017667:Adipocytes / Q000166:cytology; D000328:Adult; D000367:Age Factors; D000653:Amniotic Fluid / Q000166:cytology*; D000818:Animals; D018929:Cell Culture Techniques / Q000379:methods; D002454:Cell Differentiation / Q000187:drug effects; D002471:Cell Transformation, Neoplastic; D002478:Cells, Cultured / Q000166:cytology / Q000187:drug effects / Q000637:transplantation; D003114:Colony-Forming Units Assay; D005260:Female; D005333:Fetus / Q000166:cytology*; D005865:Gestational Age; D006801:Humans; D007621:Karyotyping; D008213:Lymphocyte Activation; D045164:Mesenchymal Stem Cell Transplantation / Q000009:adverse effects; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D039902:Multipotent Stem Cells / Q000166:cytology* / Q000637:transplantation; D010006:Osteoblasts / Q000166:cytology; D011247:Pregnancy; D017154:Stromal Cells / Q000166:cytology / Q000637:transplantation; D016615:Telomere / Q000648:ultrastructure