title: Induction of Adipogenesis by External Volume Expansion.
abstract: BACKGROUND
  External volume expansion by suction is used to prepare the recipient site for fat grafting by increasing its compliance and vascularity. The authors previously developed a mouse model for external volume expansion and demonstrated its pro-proliferative and angiogenic effects. Increased thickness of the subcutaneous tissue was also observed. This study was thus designed to assess the adipogenic potential of external volume expansion stimulation.
  
  
  METHODS
  A miniaturized external volume expansion device consisting of a rubber dome connected to a -25 mmHg suction source was applied to the dorsum of mice for a single 2-hour stimulation or for 2 hours daily for 5 days. Tissues were harvested up to 48 hours after the last stimulation and analyzed for edema, inflammation, and adipocyte content by staining for hematoxylin and eosin, CD45, and perilipin-A. Expression of peroxisome proliferator-activated receptor-γ (proadipogenic factor) and preadipocyte factor 1 (preadipocyte marker) was evaluated by Western blot analysis.
  
  
  RESULTS
  Both a 2-hour stimulation and cyclical 2-hour stimulation for 5 days induced 1.5- and 1.9-fold increases in the number of adipocytes per millimeter. Edema was present in the immediate poststimulation period, and inflammation was seen 2 days later. Peroxisome proliferator-activated receptor-γ was increased at the end of stimulation.
  
  
  CONCLUSIONS
  Stretch is known to stimulate proliferation, whereas edema and inflammation are both emerging proadipogenic factors. Their combination in external volume expansion seems to produce proadipogenic effects, seen even after a single 2-hour stimulation.
authors.affiliation: Boston and Worcester, Mass.; and Padova, Italy From the Tissue Engineering and Wound Healing Laboratory, Division of Plastic Surgery, Brigham and Women's Hospital-Harvard Medical School; the Division of Plastic Surgery, University of Massachusetts Medical School; and the Clinic of Plastic Surgery, University of Padova.
authors.forename: Jorge
authors.initials: J
authors.lastname: Lujan-Hernandez
authors.forename: Luca
authors.initials: L
authors.lastname: Lancerotto
authors.forename: Christoph
authors.initials: C
authors.lastname: Nabzdyk
authors.forename: Kazi Zayn
authors.initials: KZ
authors.lastname: Hassan
authors.forename: Giorgio
authors.initials: G
authors.lastname: Giatsidis
authors.forename: Roger K
authors.initials: RK
authors.lastname: Khouri
authors.forename: Michael S
authors.initials: MS
authors.lastname: Chin
authors.forename: Franco
authors.initials: F
authors.lastname: Bassetto
authors.forename: Janice F
authors.initials: JF
authors.lastname: Lalikos
authors.forename: Dennis P
authors.initials: DP
authors.lastname: Orgill
mesh_terms: D017667:Adipocytes / Q000166:cytology* / Q000502:physiology; D050156:Adipogenesis / Q000502:physiology*; D000818:Animals; D015153:Blotting, Western; D049109:Cell Proliferation / Q000502:physiology; D008297:Male; D051379:Mice; D008812:Mice, Hairless; D023421:Models, Animal; D011897:Random Allocation; D012680:Sensitivity and Specificity; D050151:Subcutaneous Fat / Q000378:metabolism; D015626:Tissue Expansion / Q000295:instrumentation / Q000379:methods*; D015625:Tissue Expansion Devices