title: Cell sources for nucleus pulposus regeneration.
abstract: OBJECTIVE
  There is increasing interest in the development of cell therapy as a possible approach for the treatment of degenerative disc disease. To regenerate nucleus pulposus tissue, the cells must produce an appropriate proteoglycan-rich matrix, as this is essential for the functioning of the intervertebral disc. The natural environment within the disc is very challenging to implanted cells, particularly if they have been subcultured in normal laboratory conditions. The purpose of this work is to discuss parameters relevant to translating different proposed cell therapies of IVD into clinical use.
  
  
  RESULTS
  Several sources of cells have been proposed, including nucleus pulposus cells, chondrocytes and mesenchymal stem cells derived from bone marrow or adipose tissue. There are some clinical trials and reports of attempts to regenerate nucleus pulposus utilising either autologous or allogenic cells. While the published results of clinical applications of these cell therapies do not indicate any safety issues, additional evidence will be needed to prove their long-term efficacy.
  
  
  CONCLUSIONS
  This article discusses parameters relevant for successful translation of research on different cell sources into clinically applicable cell therapies: the influence of the intervertebral disc microenvironment on the cell phenotype, issues associated with cell culture and technical preparation of cell products, as well as discussing current regulatory requirements. There are advantages and disadvantages of each proposed cell type, but no strong evidence to favour any one particular cell source at the moment.
authors.affiliation: Educell Ltd., Prevale 9, Trzin, Slovenia, nevenka.kregar@educell.si.
authors.forename: Nevenka
authors.initials: N
authors.lastname: Kregar Velikonja
authors.forename: Jill
authors.initials: J
authors.lastname: Urban
authors.forename: Mirjam
authors.initials: M
authors.lastname: Fröhlich
authors.forename: Cornelia
authors.initials: C
authors.lastname: Neidlinger-Wilke
authors.forename: Dimitris
authors.initials: D
authors.lastname: Kletsas
authors.forename: Urska
authors.initials: U
authors.lastname: Potocar
authors.forename: Sarah
authors.initials: S
authors.lastname: Turner
authors.forename: Sally
authors.initials: S
authors.lastname: Roberts
mesh_terms: D064987:Cell- and Tissue-Based Therapy; D019902:Chondrocytes / Q000166:cytology / Q000637:transplantation; D006801:Humans; D007403:Intervertebral Disc / Q000502:physiology*; D055959:Intervertebral Disc Degeneration / Q000628:therapy*; D045164:Mesenchymal Stem Cell Transplantation; D059630:Mesenchymal Stem Cells / Q000166:cytology; D011509:Proteoglycans / Q000378:metabolism; D012038:Regeneration
chemical_list: D011509:Proteoglycans