title: Influence of decantation, washing and centrifugation on adipocyte and mesenchymal stem cell content of aspirated adipose tissue: a comparative study.
abstract: BACKGROUND
  In the last decade, controversy has arisen regarding the influence of fat harvesting, processing and injection techniques on adipose tissue graft. The aim of this study is to compare the influence of three widely used fat processing techniques in plastic surgery on the viability and number of adipocytes and mesenchymal stem cells (MSCs) of aspirated fat.
  
  
  METHODS
  A prospective cross-sectional study was conducted in 20 adult healthy female patients in whom material obtained by liposuction of the lower abdomen was separated and processed by decantation, washing or centrifugation. The morphology and quantity of adipocytes were determined by histological analysis. The viability and number of MSCs in the middle layer of each lipoaspirate and the pellet derived from centrifuged samples were obtained by multi-colour flow cytometry.
  
  
  RESULTS
  Cell count per high-powered field of intact nucleated adipocytes was significantly greater in decanted lipoaspirates, whereas centrifuged samples showed a greater majority of altered adipocytes. MSC concentration was significantly higher in washed lipoaspirates compared to decanted and centrifuged samples. However, the pellet collected at the bottom of the centrifuged samples showed the highest concentration of MSCs.
  
  
  CONCLUSIONS
  Based on the theory of cell survival stating the importance of adipocytes' integrity for graft survival and the theory claiming the importance of regenerative MSCs in the maintenance and stabilisation of fat transplant, washing may turn out to be the best processing technique for adipose tissue graft take. While eliminating most contaminants during the process, it preserved and maintained the quantity, integrity and viability of the most important components of aspirated adipose tissue.
authors.affiliation: Department of Plastic Surgery, Pontifical Catholic University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil. acondegreen@yahoo.com
authors.forename: Alexandra
authors.initials: A
authors.lastname: Condé-Green
authors.forename: Natale Ferreira Gontijo
authors.initials: NF
authors.lastname: de Amorim
authors.forename: Ivo
authors.initials: I
authors.lastname: Pitanguy
mesh_terms: D017667:Adipocytes / Q000166:cytology*; D000273:Adipose Tissue / Q000166:cytology*; D000328:Adult; D002498:Centrifugation; D003430:Cross-Sectional Studies; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D015187:Lipectomy; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D008875:Middle Aged; D011446:Prospective Studies; D012016:Reference Values; D015203:Reproducibility of Results; D014021:Tissue Preservation / Q000379:methods; D020858:Tissue and Organ Harvesting / Q000379:methods*