title: Optimizing in vitro culture conditions leads to a significantly shorter production time of human dermo-epidermal skin substitutes.
abstract: BACKGROUND
  Autologous dermo-epidermal skin substitutes (DESS) generated in vitro represent a promising therapeutic means to treat full-thickness skin defects in clinical practice. A serious drawback with regard to acute patients is the relatively long production time of 3-4 weeks. With this experimental study we aimed to decrease the production time of DESS without compromising their quality.
  
  
  METHODS
  Two in vitro steps of DESS construction were varied: the pre-cultivation time of fibroblasts in hydrogels (1, 3, and 6 days), and the culture time of keratinocytes (3, 6, and 12 days) before transplantation of DESS on nude rats. Additionally, the impact of the air-liquid interface culture during 3 days before transplantation was investigated. 3 weeks after transplantation, the macroscopic appearance was evaluated and histological sections were produced to analyze structure and thickness of epidermis and dermis, the stratification of the epidermis, and the presence of a basal lamina.
  
  
  RESULTS
  Optimal DESS formation was obtained with a fibroblast pre-cultivation time of 6 days. The minimal culture time of keratinocytes on hydrogels was also 6 days. The air-liquid interface culture did not improve graft quality.
  
  
  CONCLUSIONS
  By optimizing our in vitro culture conditions, it was possible to very substantially reduce the production time for DESS from 21 to 12 days. However, pre-cultivation of fibroblasts in the dermal equivalent and proliferation of keratinocytes before transplantation remain crucial for an equilibrated maturation of the epidermis and cannot be completely skipped.
authors: Tissue Biology Research Unit, University Children's Hospital Zurich, Zurich, Switzerland.
authors: Luca
authors: L
authors: Pontiggia
authors: Agnieszka
authors: A
authors: Klar
authors: Sophie
authors: S
authors: Böttcher-Haberzeth
authors: Thomas
authors: T
authors: Biedermann
authors: Martin
authors: M
authors: Meuli
authors: Ernst
authors: E
authors: Reichmann
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D049109:Cell Proliferation; D002648:Child; D002675:Child, Preschool; D046508:Culture Techniques; D020405:Dermis / Q000166:cytology; D000078404:Epidermal Cells; D005260:Female; D005347:Fibroblasts / Q000166:cytology* / Q000637:transplantation*; D006801:Humans; D007223:Infant; D015603:Keratinocytes / Q000166:cytology* / Q000637:transplantation*; D008297:Male; D008875:Middle Aged; D051381:Rats; D016038:Skin Transplantation; D017768:Skin, Artificial; D013997:Time Factors; D023822:Tissue Engineering / Q000379:methods*; D014182:Transplantation, Autologous; D055815:Young Adult
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