title: Expansion and redifferentiation of chondrocytes from osteoarthritic cartilage: cells for human cartilage tissue engineering.
abstract: OBJECTIVE
  To determine if selected culture conditions enhance the expansion and redifferentiation of chondrocytes isolated from human osteoarthritic cartilage with yields appropriate for creation of constructs for treatment of joint-scale cartilage defects, damage, or osteoarthritis.
  
  
  METHODS
  Chondrocytes isolated from osteoarthritic cartilage were analyzed to determine the effects of medium supplement on cell expansion in monolayer and then cell redifferentiation in alginate beads. Expansion was assessed as cell number estimated from DNA, growth rate, and day of maximal growth. Redifferentiation was evaluated quantitatively from proteoglycan and collagen type II content, and qualitatively by histology and immunohistochemistry.
  
  
  RESULTS
  Using either serum or a growth factor cocktail (TFP: transforming growth factor beta1, fibroblast growth factor 2, and platelet-derived growth factor type bb), cell growth rate in monolayer was increased to 5.5x that of corresponding conditions without TFP, and cell number increased 100-fold within 17 days. In subsequent alginate bead culture with human serum or transforming growth factor beta1 and insulin-transferrin-selenium-linoleic acid-bovine serum albumin, redifferentiation was enhanced with increased proteoglycan and collagen type II production. Effects of human serum were dose dependent, and 5% or higher induced formation of chondron-like structures with abundant proteoglycan-rich matrix.
  
  
  CONCLUSIONS
  Chondrocytes from osteoarthritic cartilage can be stimulated to undergo 100-fold expansion and then redifferentiation, suggesting that they may be useful as a cell source for joint-scale cartilage tissue engineering.
authors.affiliation: Department of Mechanical and Aerospace Engineering, University of California-San Diego, La Jolla, California 92093-0412, USA.
authors.forename: Nancy D
authors.initials: ND
authors.lastname: Hsieh-Bonassera
authors.forename: Iwen
authors.initials: I
authors.lastname: Wu
authors.forename: Jonathan K
authors.initials: JK
authors.lastname: Lin
authors.forename: Barbara L
authors.initials: BL
authors.lastname: Schumacher
authors.forename: Albert C
authors.initials: AC
authors.lastname: Chen
authors.forename: Koichi
authors.initials: K
authors.lastname: Masuda
authors.forename: William D
authors.initials: WD
authors.lastname: Bugbee
authors.forename: Robert L
authors.initials: RL
authors.lastname: Sah
mesh_terms: D000368:Aged; D002356:Cartilage / Q000254:growth & development* / Q000473:pathology*; D018929:Cell Culture Techniques / Q000379:methods; D002454:Cell Differentiation; D049109:Cell Proliferation; D002478:Cells, Cultured; D019902:Chondrocytes / Q000473:pathology*; D020219:Chondrogenesis / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000473:pathology*; D023822:Tissue Engineering / Q000379:methods*