title: A static, closed and scaffold-free bioreactor system that permits chondrogenesis in vitro.
abstract: OBJECTIVE
  To characterise in vitro engineered cartilaginous constructs made employing a novel static, scaffold-free and closed chamber system.
  
  
  METHODS
  Chondrocytes derived from slaughter age pigs (3-6 months) were seeded at high density (20 x 10(6)) into cylindrical chambers (1.0 x 0.5cm) and were maintained between an upper and a lower membrane (100 kDa) for 21 days and subsequently cultured in open culture for 7 additional days.
  
  
  RESULTS
  Viable constructs produced were approximately 10 mmx2mm in size and were stable enough to be handled by surgical pincers. Histology and electron microscopy evaluations revealed a neo-cartilage structure of high cell density with a comprehensive extracellular matrix. Predominately collagen type II and negligible amounts of collagen types I and X were detected using RT-PCR and SDS-PAGE analyses.
  
  
  CONCLUSIONS
  In this study, we provide evidence of a scaffold-free system that can produce immature hyaline-like cartilaginous constructs suitable for in vivo implantation, or that may be useful for in vitro studies of events related to the process of chondrogenesis.
authors.affiliation: Osteoarticular Research Group, Institute of Pathology, University of Bern, Bern, Switzerland.
authors.forename: S P
authors.initials: SP
authors.lastname: Grogan
authors.forename: F
authors.initials: F
authors.lastname: Rieser
authors.forename: V
authors.initials: V
authors.lastname: Winkelmann
authors.forename: S
authors.initials: S
authors.lastname: Berardi
authors.forename: P
authors.initials: P
authors.lastname: Mainil-Varlet
mesh_terms: D000818:Animals; D019149:Bioreactors; D002478:Cells, Cultured; D019902:Chondrocytes / Q000648:ultrastructure*; D024042:Collagen Type I / Q000648:ultrastructure; D024043:Collagen Type II / Q000648:ultrastructure; D024121:Collagen Type X / Q000648:ultrastructure; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D005109:Extracellular Matrix / Q000648:ultrastructure; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D013552:Swine
chemical_list: D024042:Collagen Type I; D024043:Collagen Type II; D024121:Collagen Type X