title: Matrix forming characteristics of inner and outer human meniscus cells on 3D collagen scaffolds under normal and low oxygen tensions.
abstract: BACKGROUND
  Limited intrinsic healing potential of the meniscus and a strong correlation between meniscal injury and osteoarthritis have prompted investigation of surgical repair options, including the implantation of functional bioengineered constructs. Cell-based constructs appear promising, however the generation of meniscal constructs is complicated by the presence of diverse cell populations within this heterogeneous tissue and gaps in the information concerning their response to manipulation of oxygen tension during cell culture.
  
  
  METHODS
  Four human lateral menisci were harvested from patients undergoing total knee replacement. Inner and outer meniscal fibrochondrocytes (MFCs) were expanded to passage 3 in growth medium supplemented with basic fibroblast growth factor (FGF-2), then embedded in porous collagen type I scaffolds and chondrogenically stimulated with transforming growth factor β3 (TGF-β3) under 21% (normal or normoxic) or 3% (hypoxic) oxygen tension for 21 days. Following scaffold culture, constructs were analyzed biochemically for glycosaminoglycan production, histologically for deposition of extracellular matrix (ECM), as well as at the molecular level for expression of characteristic mRNA transcripts.
  
  
  RESULTS
  Constructs cultured under normal oxygen tension expressed higher levels of collagen type II (p = 0.05), aggrecan (p < 0.05) and cartilage oligomeric matrix protein, (COMP) (p < 0.05) compared to hypoxic expanded and cultured constructs. Accumulation of ECM rich in collagen type II and sulfated proteoglycan was evident in normoxic cultured scaffolds compared to those under low oxygen tension. There was no significant difference in expression of these genes between scaffolds seeded with MFCs isolated from inner or outer regions of the tissue following 21 days chondrogenic stimulation (p > 0.05).
  
  
  CONCLUSIONS
  Cells isolated from inner and outer regions of the human meniscus demonstrated equivalent differentiation potential toward chondrogenic phenotype and ECM production. Oxygen tension played a key role in modulating the redifferentiation of meniscal fibrochondrocytes on a 3D collagen scaffold in vitro.
authors: Roger
authors: R
authors: Croutze
authors: Nadr
authors: N
authors: Jomha
authors: Hasan
authors: H
authors: Uludag
authors: Department of Surgery, Division of Orthopaedic Surgery, Laboratory of Stem Cell Biology and Orthopaedic Tissue Engineering, University of Alberta, Faculty of Medicine and Dentistry, 3,002E Li Ka Shing Centre for Health Research Innovation, Edmonton, AB T6G 2E1, Canada. adesida@ualberta.ca.
authors: Adetola
authors: A
authors: Adesida
mesh_terms: D000368:Aged; D053674:Aggrecans / Q000378:metabolism; D064236:Cartilage Oligomeric Matrix Protein / Q000378:metabolism; D054337:Cell Dedifferentiation; D002454:Cell Differentiation; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology* / Q000378:metabolism; D020219:Chondrogenesis; D024042:Collagen Type I / Q000378:metabolism; D024043:Collagen Type II / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism*; D005260:Female; D005347:Fibroblasts / Q000166:cytology* / Q000378:metabolism; D015870:Gene Expression; D006801:Humans; D008592:Menisci, Tibial / Q000166:cytology* / Q000378:metabolism; D008875:Middle Aged; D010100:Oxygen / Q000502:physiology*; D010619:Phenazines; D010641:Phenotype; D054457:Tissue Scaffolds
chemical_list: D053674:Aggrecans; D064236:Cartilage Oligomeric Matrix Protein; D024042:Collagen Type I; D024043:Collagen Type II; D010619:Phenazines; D010100:Oxygen; C009195:safranine T