title: Effects of centrifugation on cell composition and viability of aspirated adipose tissue processed for transplantation.
abstract: BACKGROUND
  Centrifugation is one of the preferred methods of fat processing. Although it has been promoted for nearly three decades to separate adipose tissue components before grafting, there remain many controversies regarding the results obtained with centrifuged adipose tissue.
  
  
  OBJECTIVE
  The authors demonstrate the effects of centrifugation on the cellular components of aspirated fat.
  
  
  METHODS
  Fat harvested from the lower abdomen of 10 female patients undergoing liposuction was divided in two equal parts, then processed by decantation or centrifugation and sent to the laboratory. Each processed lipoaspirate was analyzed histologically after hematoxylin and periodic acid-Schiff staining for the presence of intact adipocytes. It was then cultured and analyzed by multicolor flow cytometry for identification of adipose-derived mesenchymal stem cells.
  
  
  RESULTS
  The middle layer of the centrifuged lipoaspirate, which is used by many surgeons, showed a great majority of altered adipocytes and very few mesenchymal stem cells in comparison with the decanted sample, which maintained the integrity of the adipocytes and showed a greater number of mesenchymal stem cells. The pellet observed as a fourth layer at the bottom of the centrifuged lipoaspirate showed the greatest concentration of endothelial cells and mesenchymal stem cells, which play a crucial role in the angiogenic and adipogenic effect of the grafted tissue.
  
  
  CONCLUSIONS
  If centrifuged lipoaspirate is used, the pellet (rich in adipose-derived mesenchymal stem cells) and the middle layer should be employed to increase fat graft survival.
authors.affiliation: Department of Plastic Surgery, Pontifical Catholic University of Rio de Janeiro, Rio de Janeiro, Brazil. acondegreen@yahoo.com
authors.forename: Alexandra
authors.initials: A
authors.lastname: Condé-Green
authors.forename: Leandra Santos
authors.initials: LS
authors.lastname: Baptista
authors.forename: Natale Ferreira Gontijo
authors.initials: NF
authors.lastname: de Amorin
authors.forename: Eduardo Duarte
authors.initials: ED
authors.lastname: de Oliveira
authors.forename: Karina Ribeiro
authors.initials: KR
authors.lastname: da Silva
authors.forename: Carolina da Silva Gouveia
authors.initials: Cda S
authors.lastname: Pedrosa
authors.forename: Radovan
authors.initials: R
authors.lastname: Borojevic
authors.forename: Ivo
authors.initials: I
authors.lastname: Pitanguy
mesh_terms: D017667:Adipocytes; D000273:Adipose Tissue / Q000166:cytology* / Q000637:transplantation*; D000328:Adult; D002498:Centrifugation / Q000379:methods*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D015187:Lipectomy; D059630:Mesenchymal Stem Cells; D008875:Middle Aged; D011446:Prospective Studies; D013194:Staining and Labeling