title: Comparison of articular cartilage repair by autologous chondrocytes with and without in vitro cultivation.
abstract: OBJECTIVE
  autologous chondrocyte implantation usually requires in vitro cell expansion before implantation. We compared the efficacy of cartilage regeneration by in vitro-expanded chondrocytes at high density and freshly harvested chondrocytes at low density.
  
  
  METHODS
  surgically created osteochondral defects at weight-bearing surface of femoral condyles of domestic pigs were repaired by biphasic cylindrical porous plugs of DL-poly-lactide-co-glycolide and beta-tricalcium phosphate. Plugs were seeded with autologous chondrocytes in its chondral phase, and press-fit to defects. Seeded cells were (1) in vitro-expanded chondrocytes harvested from stifle joint 3 weeks before implantation and (2) freshly harvested chondrocytes from recipient knee. Seeding densities were 70 x 10(6) and 7 x 10(6) cells/mL, respectively. Cell-free plugs served as control and defects remained untreated as null control. Outcome was examined at 6 months with International Cartilage Repair Society Scale.
  
  
  RESULTS
  the two experimental groups were repaired by hyaline cartilage with collagen type II and Safranin-O. Tissue in control group was primarily fibrocartilage. No regeneration was found in null control. Experimental groups had higher mean International Cartilage Repair Society scores than control in surface, matrix, and cell distribution, but were comparable with control in cell viability, subchondral bone, and mineralization. No significant difference existed between two experimental groups in any of the six categories. Uni-axial indentation test revealed similar creeping stress-relaxation property as native cartilage on experimental, but not control, specimen.
  
  
  CONCLUSIONS
  cartilage could regenerate in both experimental models, in comparable quality. Culture of chondrocytes before implantation is not necessary.
authors.affiliation: National Taiwan University Hospital, and College of Medicine, Taipei, Taiwan.
authors.forename: Hongsen
authors.initials: H
authors.lastname: Chiang
authors.forename: Chun-Jen
authors.initials: CJ
authors.lastname: Liao
authors.forename: Yao-Hong
authors.initials: YH
authors.lastname: Wang
authors.forename: Hsin-Yi
authors.initials: HY
authors.lastname: Huang
authors.forename: Chun-Nan
authors.initials: CN
authors.lastname: Chen
authors.forename: Chang-Hsun
authors.initials: CH
authors.lastname: Hsieh
authors.forename: Yi-You
authors.initials: YY
authors.lastname: Huang
authors.forename: Ching-Chuan
authors.initials: CC
authors.lastname: Jiang
mesh_terms: D000818:Animals; D002358:Cartilage, Articular / Q000502:physiology* / Q000503:physiopathology / Q000601:surgery; D018929:Cell Culture Techniques / Q000379:methods; D049109:Cell Proliferation; D002469:Cell Separation / Q000295:instrumentation / Q000379:methods; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology* / Q000502:physiology / Q000637:transplantation*; D005260:Female; D048091:Guided Tissue Regeneration / Q000379:methods*; D007719:Knee Joint / Q000166:cytology / Q000502:physiology; D007720:Knee Prosthesis; D008297:Male; D013552:Swine; D023822:Tissue Engineering / Q000379:methods; D054457:Tissue Scaffolds; D014182:Transplantation, Autologous; D014945:Wound Healing / Q000502:physiology*