title: Canine adipose-derived stromal cell viability following exposure to synovial fluid from osteoarthritic joints.
abstract: BACKGROUND
  Stem cell therapy used in clinical application of osteoarthritis in veterinary medicine typically involves intra-articular injection of the cells, however the effect of an osteoarthritic environment on the fate of the cells has not been investigated.
  
  
  OBJECTIVE
  Assess the viability of adipose derived stromal cells following exposure to osteoarthritic joint fluid.
  
  
  METHODS
  Adipose derived stromal cells (ASCs) were derived from falciform adipose tissue of five adult dogs, and osteoarthritic synovial fluid (SF) was obtained from ten patients undergoing surgical intervention on orthopedic diseases with secondary osteoarthritis. Normal synovial fluid was obtained from seven adult dogs from an unrelated study. ASCs were exposed to the following treatment conditions: culture medium, normal SF, osteoarthritic SF, or serial dilutions of 1:1 to 1:10 of osteoarthritic SF with media. Cells were then harvested and assessed for viability using trypan blue dye exclusion.
  
  
  RESULTS
  There was no significant difference in the viability of cells in culture medium or normal SF. Significant differences were found between cells exposed to any concentration of osteoarthritic SF and normal SF and between cells exposed to undiluted osteoarthritic SF and all serial dilutions. Subsequent dilutions reduced cytotoxicity.
  
  
  CONCLUSIONS
  Osteoarthritic synovial fluid in this ex vivo experiment is cytotoxic to ASCs, when compared with normal synovial fluid. Current practice of direct injection of ASCs into osteoarthritic joints should be re-evaluated to determine if alternative means of administration may be more effective.
authors.affiliation: Department of Veterinary Clinical Sciences , College of Veterinary Medicine, University of Minnesota , St Paul, Minnesota , USA.
authors.forename: Kristina M
authors.initials: KM
authors.lastname: Kiefer
authors.affiliation: Department of Veterinary Population Medicine , College of Veterinary Medicine, University of Minnesota , St Paul, Minnesota , USA ; Stem Cell Institute, University of Minnesota, McGuire Translational Research Facility , Minneapolis, Minnesota , USA.
authors.forename: Timothy D
authors.initials: TD
authors.lastname: O'Brien
authors.affiliation: Department of Veterinary Clinical Sciences , College of Veterinary Medicine, University of Minnesota , St Paul, Minnesota , USA.
authors.forename: Elizabeth G
authors.initials: EG
authors.lastname: Pluhar
authors.affiliation: Department of Veterinary Clinical Sciences , College of Veterinary Medicine, University of Minnesota , St Paul, Minnesota , USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Conzemius
keywords: Arthritis; Dogs; Stem cell therapy