title: Epithelial regeneration from bioengineered skin explants in culture.
abstract: BACKGROUND
  Artificial skin substitutes are beneficial in the treatment of chronic wounds although their performance relative to authentic human skin is unclear.
  
  
  OBJECTIVE
  We compared the rate of outgrowth and morphology of neoepidermis from a bioengineered skin construct (Apligraf) with normal adult human skin explants on de-epidermized human dermal growth substrate with or without intact epidermal basement membrane zone.
  
  
  METHODS
  Epithelial outgrowth of air-exposed cultures in serum-supplemented keratinocyte medium was quantified by fluorescence imaging, morphology by light microscopy, biomarkers of keratinocyte activation, proliferation and migration by immunohistochemical analysis, and gelatinases by zymography.
  
  
  RESULTS
  Resurfacing from bioengineereed skin explants started earlier than from normal skin but subsequently, from day 3 to day 9, the rate of epidermalization from bioengineered skin was only 40% (206 +/- 23 microm day(-1), mean +/- SEM) of that of authentic skin (521 +/- 17 microm day(-1), P < 0.001). At culture termination at day 11, normal human skin had formed a multilayered and well-structured neoepidermis covering 41.0 +/- 1.2 mm2 of the dermal substrate while bioengineered skin produced a thinner, less organized epithelium covering 20.4 +/- 3.0 mm2. At this later stage, a higher expression of beta-defensin-2, keratin 16, Ki67 and matrix metalloproteinase (MMP)-9 was found in neoepidermis formed from authentic skin than from bioengineered skin. Activated MMP-2 was elevated in bioengineered skin-derived neoepidermis. Minor epithelial outgrowth was noted with either skin type on the dermal substrate devoid of basement membrane zone.
  
  
  CONCLUSIONS
  Cultured normal skin explants produced a more uniform and expansive in vivo-like neoepidermis than bioengineered skin explants.
authors.affiliation: Department of Plastic and Reconstructive Surgery, University Hospital, , Otto-von-Guericke-University, Magdeburg, Germany.
authors.forename: U
authors.initials: U
authors.lastname: Mirastschijski
authors.forename: R
authors.initials: R
authors.lastname: Bugdahl
authors.forename: O
authors.initials: O
authors.lastname: Rollman
authors.forename: B R
authors.initials: BR
authors.lastname: Johansson
authors.forename: M S
authors.initials: MS
authors.lastname: Agren
mesh_terms: D000328:Adult; D001485:Basement Membrane / Q000502:physiology; D003094:Collagen / Q000502:physiology*; D004817:Epidermis / Q000378:metabolism / Q000502:physiology* / Q000648:ultrastructure; D004848:Epithelium / Q000502:physiology; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D053536:Keratin-16; D015603:Keratinocytes / Q000502:physiology; D007633:Keratins / Q000378:metabolism; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D008855:Microscopy, Electron, Scanning; D012038:Regeneration; D017768:Skin, Artificial; D046509:Tissue Culture Techniques; D023822:Tissue Engineering / Q000379:methods*; D023083:beta-Defensins / Q000378:metabolism
chemical_list: C117898:Apligraf; C106641:DEFB4A protein, human; C507431:KRT16 protein, human; D053536:Keratin-16; D023083:beta-Defensins; D007633:Keratins; D003094:Collagen; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9