title: Evaluation of the stromal vascular fraction of adipose tissue as the basis for a stem cell-based tissue-engineered vascular graft.
abstract: One of the rate-limiting barriers within the field of vascular tissue engineering is the lengthy fabrication time associated with expanding appropriate cell types in culture. One particularly attractive cell type for this purpose is the adipose-derived mesenchymal stem cell (AD-MSC), which is abundant and easily harvested from liposuction procedures. Even this cell type has its drawbacks, however, including the required culture period for expansion, which could pose risks of cellular transformation or contamination. Eliminating culture entirely would be ideal to avoid these concerns. In this study, we used the raw population of cells obtained after digestion of human liposuction aspirates, known as the stromal vascular fraction (SVF), as an abundant, culture-free cell source for tissue-engineered vascular grafts (TEVGs).
  
  
  
  SVF cells and donor-paired cultured AD-MSCs were first assessed for their abilities to differentiate into vascular smooth muscle cells (SMCs) after angiotensin II stimulation and to secrete factors (eg, conditioned media) that promote SMC migration. Next, both cell types were incorporated into TEVG scaffolds, implanted as an aortic graft in a Lewis rat model, and assessed for their patency and composition.
  
  
  
  In general, the human SVF cells were able to perform the same functions as AD-MSCs isolated from the same donor by culture expansion. Specifically, cells within the SVF performed two important functions; namely, they were able to differentiate into SMCs (SVF calponin expression: 16.4% ± 7.7% vs AD-MSC: 19.9%% ± 1.7%) and could secrete promigratory factors (SVF migration rate relative to control: 3.1 ± 0.3 vs AD-MSC: 2.5 ± 0.5). The SVF cells were also capable of being seeded within biodegradable, elastomeric, porous scaffolds that, when implanted in vivo for 8 weeks, generated patent TEVGs (SVF: 83% patency vs AD-MSC: 100% patency) populated with primary vascular components (eg, SMCs, endothelial cells, collagen, and elastin).
  
  
  
  Human adipose tissue can be used as a culture-free cell source to create TEVGs, laying the groundwork for the rapid production of cell-seeded grafts.
authors.affiliation: Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pa; McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pa.
authors.forename: Jeffrey T
authors.initials: JT
authors.lastname: Krawiec
authors.affiliation: Department of Plastic Surgery, University of Pittsburgh, Pittsburgh, Pa; Division of Trauma Plastic Surgery, Department of Plastic and Reconstructive Surgery, Craniofacial Research Center, Chang Gung Memorial Hospital, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Han-Tsung
authors.initials: HT
authors.lastname: Liao
authors.affiliation: Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pa.
authors.forename: LaiYee Lily
authors.initials: LL
authors.lastname: Kwan
authors.affiliation: Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pa; McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pa; Department of Surgery, University of Pittsburgh, Pittsburgh, Pa; Ri.MED Foundation, Palermo, Italy; Dipartimento di Ingegneria Chimica, Gestionale, Informatica, Meccanica (DICGIM), University of Palermo, Palermo, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: D'Amore
authors.affiliation: Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pa; McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pa.
authors.forename: Justin S
authors.initials: JS
authors.lastname: Weinbaum
authors.affiliation: Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pa; McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pa; Department of Plastic Surgery, University of Pittsburgh, Pittsburgh, Pa.
authors.forename: J Peter
authors.initials: JP
authors.lastname: Rubin
authors.affiliation: Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pa; McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pa; Department of Surgery, University of Pittsburgh, Pittsburgh, Pa.
authors.forename: William R
authors.initials: WR
authors.lastname: Wagner
authors.affiliation: Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pa; McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pa; Department of Surgery, University of Pittsburgh, Pittsburgh, Pa; Department of Cardiothoracic Surgery, University of Pittsburgh, Pittsburgh, Pa. Electronic address: vorp@pitt.edu.
authors.forename: David A
authors.initials: DA
authors.lastname: Vorp
mesh_terms: D000273:Adipose Tissue / Q000098:blood supply*; D000328:Adult; D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D001012:Aorta, Abdominal / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D001705:Bioprosthesis; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000295:instrumentation* / Q000379:methods; D002454:Cell Differentiation; D002465:Cell Movement; D002469:Cell Separation; D002478:Cells, Cultured; D005260:Female; D006801:Humans; D015187:Lipectomy; D045164:Mesenchymal Stem Cell Transplantation; D059630:Mesenchymal Stem Cells / Q000187:drug effects / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism / Q000637:transplantation*; D032389:Myocytes, Smooth Muscle / Q000187:drug effects / Q000378:metabolism / Q000637:transplantation*; D010641:Phenotype; D011917:Rats, Inbred Lew; D017154:Stromal Cells / Q000187:drug effects / Q000378:metabolism / Q000637:transplantation*; D013997:Time Factors; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds
chemical_list: D000804:Angiotensin II