title: Freshly isolated stromal cells from the infrapatellar fat pad are suitable for a one-step surgical procedure to regenerate cartilage tissue.
abstract: OBJECTIVE
  Stem cell therapies are being evaluated as promising alternatives for cartilage regeneration. We investigated whether stromal vascular fraction cells (SVF) from the infrapatellar (Hoffa) fat pad are suitable for a one-step surgical procedure to treat focal cartilage defects.
  
  
  METHODS
  SVF was harvested from patients undergoing knee arthroplasty (n = 53). Colony-forming unit (CFU) assays, growth kinetics and surface marker profiles were determined, and the chondrogenic differentiation capacity of freshly isolated SVF was assessed after seeding in three-dimensional poly (L-lactic-co-epsilon-caprolactone) scaffolds.
  
  
  RESULTS
  SVF yield per fat pad varied between 0.55 and 16 x 10(6) cells. CFU frequency and population doubling time were 2.6 +/- 0.6% and +/-2 days, respectively. Surface marker profiles matched those of subcutaneous-derived adipose-derived stem cells (ASC). CFU from Hoffa SVF showed differentiation toward osteogenic and adipogenic lineages. Cartilage differentiation was confirmed by up-regulation of the cartilage genes sox9, aggrecan, collagen type II and cartilage oligomeric matrix protein (COMP), collagen II immunostaining, Alcian Blue staining and glycosaminoglycan production. Compared with passaged cells, SVF showed at least similar chondrogenic potential.
  
  
  CONCLUSIONS
  This study demonstrates that SVF cells from the infrapatellar fat pad are suitable for future application in a one-step surgical procedure to regenerate cartilage tissue. SVF shows similar favorable characteristics as cultured ASC, and chondrogenic differentiation even appears to be slightly better. However, because of variable harvesting volumes and yields, SVF from the infrapatellar fat pad might only be applicable for treatment of small focal cartilage defects, whereas for larger osteoarthritic defects subcutaneous adipose tissue depot would be preferable.
authors.affiliation: Department of Plastic, Reconstructive and Hand Surgery, VU University Medical Center, Amsterdam, the Netherlands.
authors.forename: Wouter J F M
authors.initials: WJ
authors.lastname: Jurgens
authors.forename: Annemieke
authors.initials: A
authors.lastname: van Dijk
authors.forename: Behrouz Zandieh
authors.initials: BZ
authors.lastname: Doulabi
authors.forename: Frank B
authors.initials: FB
authors.lastname: Niessen
authors.forename: Marco J P F
authors.initials: MJ
authors.lastname: Ritt
authors.forename: Florine J
authors.initials: FJ
authors.lastname: van Milligen
authors.forename: Marco N
authors.initials: MN
authors.lastname: Helder
mesh_terms: D000273:Adipose Tissue / Q000166:cytology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000378:metabolism; D002356:Cartilage / Q000502:physiology*; D002454:Cell Differentiation; D019070:Cell Lineage; D002469:Cell Separation; D002478:Cells, Cultured; D020219:Chondrogenesis / Q000235:genetics; D003114:Colony-Forming Units Assay; D005109:Extracellular Matrix / Q000235:genetics / Q000378:metabolism; D006025:Glycosaminoglycans / Q000096:biosynthesis; D006801:Humans; D008875:Middle Aged; D012038:Regeneration; D044968:Regenerative Medicine / Q000379:methods*; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism; D017154:Stromal Cells / Q000166:cytology* / Q000378:metabolism; D015854:Up-Regulation / Q000235:genetics
chemical_list: D015415:Biomarkers; D006025:Glycosaminoglycans