title: "Trooping the color": restoring the original donor skin color by addition of melanocytes to bioengineered skin analogs.
abstract: OBJECTIVE
  Autologous skin substitutes to cover large skin defects are used since several years. Melanocytes, although essential for solar protection and pigmentation of skin, are not yet systematically added to such substitutes. In this experimental study, we reconstructed melanocyte-containing dermo-epidermal skin substitutes from donor skins of different skin pigmentation types and studied them in an animal model. Features pertinent to skin color were analyzed and compared in both skin substitutes and original donor skin.
  
  
  METHODS
  Keratinocytes, melanocytes, and fibroblast were isolated, cultured, and expanded from skin biopsies of light- and dark-pigmented patients. For each donor, melanocytes and keratinocytes were seeded in different ratios (1:1, 1:5, 1:10) onto collagen gels previously populated with autologous fibroblasts. Skin substitutes were then transplanted onto full-thickness wounds of immuno-incompetent rats. After 8 weeks, macroscopic and microscopic analyses were conducted with regard to skin color and architecture.
  
  
  RESULTS
  Chromameter evaluation revealed that skin color of reconstructed light- and dark-pigmented skin was very similar to donor skin, independent of which melanocyte/keratinocyte ratio was added. Histological analyses of the skin analogs confirmed these findings.
  
  
  CONCLUSIONS
  These data suggest that adding autologous melanocytes to bioengineered dermo-epidermal skin analogs can sustainably restore the patients' native skin color.
authors.affiliation: Tissue Biology Research Unit, University Children's Hospital Zurich, Zurich, Switzerland.
authors.forename: Sophie
authors.initials: S
authors.lastname: Böttcher-Haberzeth
authors.forename: Agnieszka S
authors.initials: AS
authors.lastname: Klar
authors.forename: Thomas
authors.initials: T
authors.lastname: Biedermann
authors.forename: Clemens
authors.initials: C
authors.lastname: Schiestl
authors.forename: Claudia
authors.initials: C
authors.lastname: Meuli-Simmen
authors.forename: Ernst
authors.initials: E
authors.lastname: Reichmann
authors.forename: Martin
authors.initials: M
authors.lastname: Meuli
mesh_terms: D000293:Adolescent; D000818:Animals; D002478:Cells, Cultured; D002648:Child; D002675:Child, Preschool; D017077:Culture Media, Conditioned; D005347:Fibroblasts / Q000166:cytology; D052816:Foreskin / Q000166:cytology; D006801:Humans; D007223:Infant; D015603:Keratinocytes / Q000166:cytology; D008297:Male; D008544:Melanocytes / Q000166:cytology / Q000648:ultrastructure; D023421:Models, Animal; D051381:Rats; D012880:Skin Pigmentation; D016038:Skin Transplantation; D017768:Skin, Artificial; D023822:Tissue Engineering / Q000379:methods*
chemical_list: D017077:Culture Media, Conditioned