title: [Differential behaviour of human adult arthrotic chondrocytes under 2D- and 3D-cultivation set-ups in a collagen I gel].
abstract: OBJECTIVE
  The aim of this study was to assess the influence of culture conditions on the differentiation of human chondrocytes expanded in monolayer (2 D) or a three-dimensional (3 D) biodegradable collagen type I matrix, with regard to chondrocyte-specific markers.
  
  
  METHODS
  Human arthrotic chondrocytes were taken from nine adult donors (average age 72.1 years) undergoing knee replacement. The isolated cell suspensions were split and cultivated either in a 3-dimensional collagen gel (3 D) or in a monolayer (2 D). The amounts of mRNA for collagen I and II, aggrecan and melanoma inhibitory activity (MIA) were quantified by means of real-time PCR at different times.
  
  
  RESULTS
  The 2 D-passaged cells showed a significant increase of collagen I between P 00 and P 01 (p = 0.009), whereas the expression of collagen II decreased significantly (p = 0.022). There was no significant change for collagen I in 3 D-cultivation, whereas the collagen II expression decreased significantly after 2 to 4 weeks (p = 0.001).
  
  
  CONCLUSIONS
  Human adult chondrocytes obtained from elderly patients showed a decreased expression of collagen II with increased passaging in the monolayer (2 D). The decrease was delayed in 3 D-cultivation. We thus question the assumption that the dedifferentiation of chondrocytes can be prevented or reversed by 3 D-cultivation. Based on our results, we recommend the use of freshly isolated and therefore sparsely dedifferentiated chondrocytes for transplantation.
authors.affiliation: Orthopädische Universitätsklinik, RTWH Aachen, Germany. mayaniethard@web.de
authors.forename: M
authors.initials: M
authors.lastname: Niethard
authors.forename: U
authors.initials: U
authors.lastname: Schneider
authors.forename: R
authors.initials: R
authors.lastname: Wallich
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D053674:Aggrecans / Q000235:genetics; D001706:Biopsy; D018929:Cell Culture Techniques; D002454:Cell Differentiation / Q000502:physiology*; D019902:Chondrocytes / Q000473:pathology*; D024042:Collagen Type I / Q000235:genetics; D024043:Collagen Type II / Q000235:genetics; D003470:Culture Media; D016326:Extracellular Matrix Proteins / Q000235:genetics; D005782:Gels; D015870:Gene Expression / Q000502:physiology; D006801:Humans; D009363:Neoplasm Proteins / Q000235:genetics; D020370:Osteoarthritis, Knee / Q000473:pathology* / Q000601:surgery; D012333:RNA, Messenger / Q000235:genetics
chemical_list: D053674:Aggrecans; D024042:Collagen Type I; D024043:Collagen Type II; D003470:Culture Media; D016326:Extracellular Matrix Proteins; D005782:Gels; C090059:MIA protein, human; D009363:Neoplasm Proteins; D012333:RNA, Messenger