title: Usefulness of Skin Explants for Histologic Analysis after Fractional Photothermolysis.
abstract: BACKGROUND
  Fractional laser resurfacing treatment has been extensively investigated and is widely used. However, the mechanism underlying its effects is poorly understood because of the ethical and cosmetic problems of obtaining skin biopsies required to study the changes after laser treatment.
  
  
  OBJECTIVE
  To evaluate the usefulness of human skin explants for the investigation of fractional photothermolysis.
  
  
  METHODS
  Full-thickness discarded skin was treated in 4 ways: no treatment (control), fractional carbon dioxide laser, fractional Er:YAG laser, and fractional 1,550-nm erbium-doped fiber laser. Both treated and non-treated skin samples were cultured ex vivo at the air-medium interface for 7 days. Frozen tissue was sectioned and stained with hematoxylin & eosin for histologic examination and nitro blue tetrazolium chloride for viability testing.
  
  
  RESULTS
  Skin explants cultured for up to 3 days exhibited histologic changes similar to those observed in in vivo studies, including microscopic treatment zones surrounded by a thermal coagulation zone, re-epithelialization, and formation of microscopic epidermal necrotic debris. However, the explant structure lost its original form within 7 days of culture. The viability of skin explants was maintained for 3 days of culture but was also lost within 7 days.
  
  
  CONCLUSIONS
  The skin explant model may be a useful tool for investigating the immediate or early changes following fractional photothermolysis, but further improvements are required to evaluate the long-term and dermal changes.
authors.affiliation: Department of Dermatology, Dongtan Sacred Heart Hospital, Hallym University College of Medicine, Hwaseong, Korea.
authors.forename: Gyeong-Hun
authors.initials: GH
authors.lastname: Park
authors.affiliation: Department of Dermatology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Sung Eun
authors.initials: SE
authors.lastname: Chang
authors.affiliation: Asan Institute for Life Sciences, Seoul, Korea.
authors.forename: Seunghyun
authors.initials: S
authors.lastname: Bang
authors.affiliation: Department of Dermatology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Kwang Hee
authors.initials: KH
authors.lastname: Won
authors.affiliation: Department of Dermatology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Chong Hyun
authors.initials: CH
authors.lastname: Won
authors.affiliation: Department of Dermatology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Mi Woo
authors.initials: MW
authors.lastname: Lee
authors.affiliation: Department of Dermatology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Jee Ho
authors.initials: JH
authors.lastname: Choi
authors.affiliation: Department of Dermatology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Kee Chan
authors.initials: KC
authors.lastname: Moon
keywords: Cosmetic techniques; Laser therapy; Tissue culture techniques; Tissue survival