title: Improvement of skin quality after fat grafting: clinical observation and an animal study.
abstract: BACKGROUND
  Restoration of volume and contour defects is a challenge in plastic surgery. Autologous fat tissue transfer is gaining increasing popularity in this field. The aim of this study was to investigate the histologic modifications of the skin after fat tissue grafting on an animal model.
  
  
  METHODS
  Thirty nude mice, divided into three groups, were used in the experiment. All 30 mice received human fat tissue on one side. On the opposite side, 10 mice received nothing (negative control group), 10 mice received cell proliferation medium, and the remaining 10 mice received only subcutaneous tunneling. Eight weeks later, biopsies of the skin and subcutaneous tissue were performed and specimens were analyzed by hematoxylin-phloxin-saffron staining. Dermis thickness was measured. To differentiate human from murine collagen fibers, human and murine collagen type I antibodies were used. The other types of collagen were investigated by immunohistochemistry (immunostaining) using collagen type III, V, and VI antibodies.
  
  
  RESULTS
  Fat tissue was found in all animals. Macroscopically, fat tissue presented normal aspects, with abundant peripheral neovascularization. Histologic examination showed abundant extracellular matrix around the injected human fat tissue. This was attributable to increased type I collagen fibers of murine origin as a result of the murine fibroblast stimulation by the grafted human fat tissue. Dermal thickness after fat grafting was significantly greater. This was not attributable to inflammatory reactions, because no modification was detected in our control groups.
  
  
  CONCLUSIONS
  This study shows that fat tissue grafting stimulates a neosynthesis of collagen fibers at the recipient site and makes the dermis thicker. However, the long-term effects remain undetermined and need further investigation.
authors.affiliation: Lyon, France From the Department of Plastic, Reconstructive, and Aesthetic Surgery and the Laboratory of Skin Substitutes, Edouard Herriot Hospital; the Department of Maxillofacial and Facial Plastic Surgery, Lyon Sud Hospital; the Department of Plastic Surgery, St Joseph-St Luc Hospital; and the Institut de Biologie et Chimie des Proteines.
authors.forename: Ali
authors.initials: A
authors.lastname: Mojallal
authors.forename: Charlotte
authors.initials: C
authors.lastname: Lequeux
authors.forename: Christo
authors.initials: C
authors.lastname: Shipkov
authors.forename: Pierre
authors.initials: P
authors.lastname: Breton
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Foyatier
authors.forename: Fabienne
authors.initials: F
authors.lastname: Braye
authors.forename: Odile
authors.initials: O
authors.lastname: Damour
mesh_terms: D000273:Adipose Tissue / Q000637:transplantation*; D000818:Animals; D024042:Collagen Type I / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D051379:Mice; D008819:Mice, Nude; D012867:Skin / Q000166:cytology* / Q000378:metabolism; D014183:Transplantation, Heterologous
chemical_list: D024042:Collagen Type I