title: Bioactive glass 13-93 as a subchondral substrate for tissue-engineered osteochondral constructs: a pilot study.
abstract: BACKGROUND
  Replacement of diseased areas of the joint with tissue-engineered osteochondral grafts has shown potential in the treatment of osteoarthritis. Bioactive glasses are candidates for the osseous analog of these grafts.
  
  
  OBJECTIVE
  (1) Does Bioactive Glass 13-93 (BG 13-93) as a subchondral substrate improve collagen and glycosaminoglycan production in a tissue-engineered cartilage layer? (2) Does BG 13-93 as a culture medium supplement increase the collagen and glycosaminoglycan production and improve the mechanical properties in a tissue-engineered cartilage layer?
  
  
  METHODS
  In Study 1, bioactive glass samples (n = 4) were attached to a chondrocyte-seeded agarose layer to form an osteochondral construct, cultured for 6 weeks, and compared to controls. In Study 2, bioactive glass samples (n = 5) were cocultured with cell-seeded agarose for 6 weeks. The cell-seeded agarose layer was exposed to BG 13-93 either continuously or for the first or last 2 weeks in culture or had no exposure.
  
  
  RESULTS
  Osteochondral constructs with a BG 13-93 base had improved glycosaminoglycan deposition but less collagen II content. Agarose scaffolds that had a temporal exposure to BG 13-93 within the culture medium had improved mechanical and biochemical properties compared to continuous or no exposure.
  
  
  CONCLUSIONS
  When used as a subchondral substrate, BG 13-93 did not improve biochemical properties compared to controls. However, as a culture medium supplement, BG 13-93 improved the biochemical and mechanical properties of a tissue-engineered cartilage layer.
  
  
  CONCLUSIONS
  BG 13-93 may not be suitable in osteochondral constructs but could have potential as a medium supplement for neocartilage formation.
authors.affiliation: Comparative Orthopaedic Laboratory, University of Missouri, 900 East Campus Drive, Columbia, MO 65211, USA.
authors.forename: Prakash
authors.initials: P
authors.lastname: Jayabalan
authors.forename: Andrea R
authors.initials: AR
authors.lastname: Tan
authors.forename: Mohammed N
authors.initials: MN
authors.lastname: Rahaman
authors.forename: B Sonny
authors.initials: BS
authors.lastname: Bal
authors.forename: Clark T
authors.initials: CT
authors.lastname: Hung
authors.forename: James L
authors.initials: JL
authors.lastname: Cook
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D002356:Cartilage / Q000378:metabolism* / Q000637:transplantation; D002417:Cattle; D019902:Chondrocytes / Q000378:metabolism* / Q000637:transplantation; D020219:Chondrogenesis; D003094:Collagen / Q000096:biosynthesis; D003470:Culture Media / Q000737:chemistry; D005898:Glass / Q000737:chemistry*; D006025:Glycosaminoglycans / Q000096:biosynthesis; D010865:Pilot Projects; D012685:Sepharose / Q000737:chemistry; D013997:Time Factors; D046509:Tissue Culture Techniques; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds
chemical_list: C553965:13-93 bioactive glass; D003470:Culture Media; D006025:Glycosaminoglycans; D003094:Collagen; D012685:Sepharose