title: Availability of adipose-derived stem cells in patients undergoing vascular surgical procedures.
abstract: BACKGROUND
  Most research evaluating adipose-derived stem cells (ASC) uses tissue obtained from young, healthy patients undergoing plastic surgical procedures. Given the propensity of other adult stem cell lines to diminish with increasing patient age and co-morbidities, we assess the availability of ASC in elderly patients undergoing vascular surgical procedures, and evaluate their acquisition of endothelial cell (EC) traits to define their potential use in vascular tissue engineering.
  
  
  METHODS
  Adipose tissue obtained by liposuction from patients undergoing vascular procedures (n = 50) was digested with collagenase and centrifuged to remove mature adipocytes. The resultant number of cells, defined as the stromal-vascular (SV) pellet, was quantified. Following a 7-d culture period and negative selection for CD31 and CD45, the resultant number of ASC was quantified. After culture in differentiating media (EMG-2), ASCs were tested for the acquisition of endothelial-specific traits (expression of CD31, realignment in shear, cord formation on Matrigel).
  
  
  RESULTS
  The SV pellet contained 2.87 ± 0.34 × 10(5) cells/g fat, and the resultant number of ASCs obtained was 1.41 ± 0.18 × 10(5) cells/g fat. Flow cytometry revealed a homogeneous ASC population (>98% positive for CD13, 29, 90). Advanced age or co-morbidity (obesity, diabetes, renal or peripheral vascular disease) did not significantly alter yield of ASC. After culture in differentiating media (EMG-2), ASCs acquired each of the endothelial-specific traits.
  
  
  CONCLUSIONS
  ASC isolation appears independent of age and co-morbidities, and ASCs harvested from patients with vascular disease retain their ability to differentiate into endothelial-like cells. Adipose tissue, therefore, is a practical source of autologous, adult stem cells for vascular tissue engineering.
authors.affiliation: Department of Surgery, Division of Vascular and Endovascular Surgery, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA.
authors.forename: Lisa J
authors.initials: LJ
authors.lastname: Harris
authors.forename: Ping
authors.initials: P
authors.lastname: Zhang
authors.forename: Hamid
authors.initials: H
authors.lastname: Abdollahi
authors.forename: Nicholas A
authors.initials: NA
authors.lastname: Tarola
authors.forename: Christopher
authors.initials: C
authors.lastname: DiMatteo
authors.forename: Stephen E
authors.initials: SE
authors.lastname: McIlhenny
authors.forename: Thomas N
authors.initials: TN
authors.lastname: Tulenko
authors.forename: Paul J
authors.initials: PJ
authors.lastname: DiMuzio
mesh_terms: D000273:Adipose Tissue / Q000166:cytology*; D000328:Adult; D053687:Adult Stem Cells / Q000166:cytology*; D000367:Age Factors; D000368:Aged; D002454:Cell Differentiation; D002469:Cell Separation; D015897:Comorbidity; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D023822:Tissue Engineering; D014656:Vascular Surgical Procedures