title: Healing of full-thickness articular cartilage defects treated with cultured autologous chondrogenic satellite cells isolated from chondral stem cell niche in rabbits.
abstract: BACKGROUND
  Healing of articular cartilage has remained in question with the use of conventional treatment modalities such as subchondral drilling and microfracture. As demonstrated in the past, adult stem cells retain promising clonogenicity. Therefore, we conducted this study to elucidate the effects of cultured autologous chondrogenic satellite cells (CACSCs) compared with subchondral drilling (SCD) for the repair of full-thickness articular cartilage defects.
  
  
  METHODS
  We examined CACSCs isolated from the knee of rabbits using flow cytometry for the expression of stemness and chondrocyte-specific factors. Subsequently, we created a full-thickness cartilage defect model with a diameter of 3 mm and depth of 2 mm on the articular surface of trochlear grooves in the left knee of 24 New Zealand white rabbits. Then we drilled subchondrally through the defect in all animals and stuffed the defects with 10-μg/cm(2) collagen scaffolds. In the treatment group, we instilled CACSCs at 5 × 10(6) cells/mL in the collagen scaffold and collected samples on days 15, 30, and 45.
  
  
  RESULTS
  The CACSCs revealed significant expression of CD106, CD44, collagen type 2, and aggrecan. In conjunction with SCD, CACSCs improved healing of the articular cartilage defect, as evidenced by the formation of hyaline-like tissue grossly and histologically. The healed tissue also revealed a significant (P < 0.05) increase in the expression of collagen type 2 and aggrecan (by real-time polymerase chain reaction) during the experiment.
  
  
  CONCLUSIONS
  In conjunction with SCD, CACSCs may be considered to improve articular cartilage damage.
authors.affiliation: Department of Animal Biotechnology, College of Animal Life Sciences, Kangwon National University, Chuncheon, South Korea. sjlee@kangwon.ac.kr
authors.forename: Naresh Kumar
authors.initials: NK
authors.lastname: Singh
authors.forename: Gaj Raj
authors.initials: GR
authors.lastname: Singh
authors.forename: Dong Kee
authors.initials: DK
authors.lastname: Jeong
authors.forename: Sung Jin
authors.initials: SJ
authors.lastname: Lee
mesh_terms: D000818:Animals; D002356:Cartilage / Q000166:cytology / Q000378:metabolism / Q000601:surgery*; D064987:Cell- and Tissue-Based Therapy; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology / Q000378:metabolism / Q000637:transplantation*; D024043:Collagen Type II / Q000378:metabolism; D005260:Female; D018960:Hyaluronan Receptors / Q000378:metabolism; D008297:Male; D023421:Models, Animal; D011817:Rabbits; D055153:Stem Cell Niche / Q000502:physiology*; D033581:Stem Cell Transplantation; D054457:Tissue Scaffolds; D019010:Vascular Cell Adhesion Molecule-1 / Q000378:metabolism; D014945:Wound Healing / Q000502:physiology*
chemical_list: D024043:Collagen Type II; D018960:Hyaluronan Receptors; D019010:Vascular Cell Adhesion Molecule-1
keywords: Aggrecan; Articular cartilage; CD106; CD44; Chondrogenic satellite cells; Coll type 2; Proteoglycan; Subchondral drilling