title: Novel model for evaluation of epidermal preservation and dermal collagen remodeling following photorejuvenation of human skin.
abstract: OBJECTIVE
  In order to optimize photorejuvenation of human skin, a method must be developed to reliably compare the potential for epidermal preservation and dermal fibroblast stimulation of different laser devices and irradiation parameters. We describe a novel human skin tissue culture model developed for this purpose.
  
  
  METHODS
  An artificial skin model, consisting of human keratinocytes in the epidermis and human fibroblasts and rat-tail collagen in the dermis, was cultured using the floating collagen gel (RAFT) method. Repetitive low-fluence Er:YAG laser irradiation was applied to test the applicability of our RAFT model for characterization of epidermal preservation and dermal fibroblast stimulation post-laser treatment.
  
  
  RESULTS
  Histopathologic evaluation revealed a thin layer of epidermal keratinocyte preservation immediately after low fluence sub-ablative Er:YAG laser irradiation. One-week post-laser irradiation, the average increase in number of dermal fibroblasts as compared to control was statistically significant (P < 0.01).
  
  
  CONCLUSIONS
  The RAFT model can be used to assess the potential for epidermal preservation and dermal fibroblast stimulation of different photorejuvenation devices and irradiation parameters and offers several advantages over traditional animal and human skin models.
authors.affiliation: Department of Dermatology and Surgery, Beckman Laser Institute and Medical Clinic, University of California, Irvine, California 92612, USA.
authors.forename: Bunsho
authors.initials: B
authors.lastname: Kao
authors.forename: Kristen M
authors.initials: KM
authors.lastname: Kelly
authors.forename: Boris
authors.initials: B
authors.lastname: Majaron
authors.forename: J Stuart
authors.initials: JS
authors.lastname: Nelson
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D003094:Collagen / Q000502:physiology; D000078404:Epidermal Cells; D004817:Epidermis / Q000528:radiation effects*; D005347:Fibroblasts / Q000378:metabolism*; D006801:Humans; D015603:Keratinocytes / Q000502:physiology; D028022:Low-Level Light Therapy; D008954:Models, Biological; D051381:Rats; D012016:Reference Values; D017768:Skin, Artificial
chemical_list: D003094:Collagen