title: *Human Amniotic Mesenchymal Stromal Cells as Favorable Source for Cartilage Repair.
abstract: Localized trauma-derived breakdown of the hyaline articular cartilage may progress toward osteoarthritis, a degenerative condition characterized by total loss of articular cartilage and joint function. Tissue engineering technologies encompass several promising approaches with high therapeutic potential for the treatment of these focal defects. However, most of the research in tissue engineering is focused on potential materials and structural cues, while little attention is directed to the most appropriate source of cells endowing these materials. In this study, using human amniotic membrane (HAM) as scaffold, we defined a novel static in vitro model for cartilage repair. In combination with HAM, four different cell types, human chondrocytes, human bone marrow-derived mesenchymal stromal cells (hBMSCs), human amniotic epithelial cells, and human amniotic mesenchymal stromal cells (hAMSCs) were assessed determining their therapeutic potential.
  
  
  
  A chondral lesion was drilled in human cartilage biopsies simulating a focal defect. A pellet of different cell types was implanted inside the lesion and covered with HAM. The biopsies were maintained for 8 weeks in culture. Chondrogenic differentiation in the defect was analyzed by histology and immunohistochemistry.
  
  
  
  HAM scaffold showed good integration and adhesion to the native cartilage in all groups. Although all cell types showed the capacity of filling the focal defect, hBMSCs and hAMSCs demonstrated higher levels of new matrix synthesis. However, only the hAMSCs-containing group presented a significant cytoplasmic content of type II collagen when compared with chondrocytes. More collagen type I was identified in the new synthesized tissue of hBMSCs. In accordance, hBMSCs and hAMSCs showed better International Cartilage Research Society scoring although without statistical significance.
  
  
  
  HAM is a useful material for articular cartilage repair in vitro when used as scaffold. In combination with hAMSCs, HAM showed better potential for cartilage repair with similar reparation capacity than chondrocytes.
authors.affiliation: 1 Tissue Bioengineering and Cell Therapy Unit (GBTTC-CHUAC), CIBER-BBN/ISCIII, Rheumatology Group, Institute of Biomedical Research of A Coruña (INIBIC), University Hospital Complex A Coruña (CHUAC) , Galician Health Service (SERGAS), A Coruña, Spain .
authors.forename: Emma
authors.initials: E
authors.lastname: Muiños-López
authors.affiliation: 1 Tissue Bioengineering and Cell Therapy Unit (GBTTC-CHUAC), CIBER-BBN/ISCIII, Rheumatology Group, Institute of Biomedical Research of A Coruña (INIBIC), University Hospital Complex A Coruña (CHUAC) , Galician Health Service (SERGAS), A Coruña, Spain .
authors.forename: Tamara
authors.initials: T
authors.lastname: Hermida-Gómez
authors.affiliation: 2 Cell Therapy and Regenerative Medicine Unit, CIBER-BBN/ISCIII, Rheumatology Group, Institute of Biomedical Research of A Coruña (INIBIC), University Hospital Complex A Coruña (CHUAC), Galician Health Service (SERGAS), Department of Medicine, Faculty of Health Sciences, University of A Coruña , A Coruña, Spain .
authors.forename: Isaac
authors.initials: I
authors.lastname: Fuentes-Boquete
authors.affiliation: 3 Reumathology Service, Cell Therapy and Regenerative Medicine Unit, CIBER-BBN/ISCIII, Rheumatology Group, Institute of Biomedical Research of A Coruña (INIBIC), University Hospital Complex A Coruña (CHUAC), Galician Health Service (SERGAS), Department of Medicine, Faculty of Health Sciences, University of A Coruña , A Coruña, Spain .
authors.forename: Javier
authors.initials: J
authors.lastname: de Toro-Santos
authors.affiliation: 4 Reumathology Service, Tissue Bioengineering and Cell Therapy Unit (GBTTC-CHUAC), CIBER-BBN/ISCIII, Rheumatology Group, Institute of Biomedical Research of A Coruña (INIBIC), University Hospital Complex A Coruña (CHUAC), Galician Health Service (SERGAS), Faculty of Medicine, University of Santiago de Compostela , A Coruña, Spain .
authors.forename: Francisco Javier
authors.initials: FJ
authors.lastname: Blanco
authors.affiliation: 2 Cell Therapy and Regenerative Medicine Unit, CIBER-BBN/ISCIII, Rheumatology Group, Institute of Biomedical Research of A Coruña (INIBIC), University Hospital Complex A Coruña (CHUAC), Galician Health Service (SERGAS), Department of Medicine, Faculty of Health Sciences, University of A Coruña , A Coruña, Spain .
authors.forename: Silvia María
authors.initials: SM
authors.lastname: Díaz-Prado
mesh_terms: D000650:Amnion / Q000166:cytology / Q000378:metabolism*; D002356:Cartilage / Q000166:cytology / Q000378:metabolism*; D002454:Cell Differentiation; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000378:metabolism*; D008954:Models, Biological; D054457:Tissue Scaffolds / Q000737:chemistry*
keywords: amniotic membrane; amniotic mesenchymal stromal cells; bone marrow mesenchymal stromal cells; cartilage; cell therapy; chondrocytes; osteoarthritis; tissue engineering