title: Purified viable fat suspended in matrigel improves volume longevity.
abstract: BACKGROUND
  Autologous fat is an excellent soft tissue filler with cosmetic and reconstructive utility. However, graft longevity is unpredictable.
  
  
  OBJECTIVE
  This study sought to evaluate the effect on in vivo fat graft performance of contemporary adipocyte tissue engineering techniques that have not previously been applied to mature fat cells due to the difficulty of their purification and their high metabolic demand.
  
  
  METHODS
  Using a recently reported protocol, the adipocyte viability and purity of lipo-harvested fat were optimized. Before graft administration, these purified cells were suspended in GFR-Matrigel (BDBiosciences), a basement membrane protein matrix known to improve early angiogenesis. It was posited that by suspending the purified cells in this resorbable matrix, the high metabolic demand of these cells would be met and graft performance could be improved. The in vivo longevity of these tissue engineered fat grafts was tested in a murine model in which each subject received posterior subcutaneous injections of three types of fat graft: unpurified fat after lipo-harvest alone; fat harvested in identical fashion, but purified and suspended in GFR-Matrigel; and a control of GFR-Matrigel alone. Graft volumes and quantitative histologic characteristics were examined at 1 week, 1 month, and 3 months.
  
  
  RESULTS
  At 3 months, purified fat/GFR Matrigel grafts showed superior fat volume maintenance (80.2% versus 29.7% for unpurified grafts [P < .05]) and adipocyte cellular longevity (70.1% versus 45.6% [P < .001). Unpurified grafts were largely replaced by fibrosis at 3 months (96.5% [95% CI 0.90-0.970]), despite starting with three times as many viable adipocytes as purified grafts. A correlation was noted between the poor performance of unpurified grafts and a disproportionate presence of early inflammation in fat grafts prepared without purification techniques.
  
  
  CONCLUSIONS
  A preparatory regimen consisting of a preadministration purification followed by cellular suspension in a resorbable protein matrix may ultimately improve the predictability and longevity of autologous fat grafts.
authors.affiliation: University of Wisconsin Hospital and Clinics, Madison, WI, USA.
authors.forename: Justin Howard
authors.initials: JH
authors.lastname: Piasecki
authors.forename: Karol A
authors.initials: KA
authors.lastname: Gutowski
authors.forename: Katherine M
authors.initials: KM
authors.lastname: Moreno
authors.forename: Garet L
authors.initials: GL
authors.lastname: Lahvis
mesh_terms: D017667:Adipocytes / Q000166:cytology / Q000637:transplantation*; D000818:Animals; D001672:Biocompatible Materials; D048429:Cell Size; D003094:Collagen; D004338:Drug Combinations; D020662:Guanine Nucleotide Exchange Factors; D007797:Laminin; D051379:Mice; D023421:Models, Animal; D011509:Proteoglycans; D011897:Random Allocation; D050151:Subcutaneous Fat / Q000098:blood supply / Q000637:transplantation*; D014022:Tissue Survival / Q000187:drug effects; D020663:ras Guanine Nucleotide Exchange Factors
chemical_list: D001672:Biocompatible Materials; D004338:Drug Combinations; D020662:Guanine Nucleotide Exchange Factors; D007797:Laminin; D011509:Proteoglycans; C417242:RAPGEF5 protein, human; D020663:ras Guanine Nucleotide Exchange Factors; C059485:matrigel; D003094:Collagen