title: Light-emitting diode-generated red light inhibits keloid fibroblast proliferation.
abstract: BACKGROUND
  Red light is part of the visible light spectrum that does not generate DNA adducts associated with skin cancer and photoaging and may represent a safer therapeutic modality for treatment of keloid scars and other fibrotic skin diseases. Our laboratory previously demonstrated that light-emitting diode-generated red light (LED-RL) inhibits proliferation of skin fibroblasts. The effects of LED-RL on keloidal skin are not well characterized.
  
  
  OBJECTIVE
  To determine the effect of LED-RL on keloid-derived fibroblast proliferation and viability in vitro.
  
  
  METHODS
  Irradiation of primary keloid-derived human skin fibroblasts using LED-RL panels was performed in vitro, and modulation of proliferation and viability was quantified using trypan blue dye exclusion assay. Statistical analysis was performed using analysis of variance to compare treatment arms and the Student t-test to compare each treatment arm with the paired bench control arm.
  
  
  RESULTS
  Keloid fibroblasts treated with LED-RL 240, 320, and 480 J/cm demonstrated statistically significant dose-dependent decreases in relative proliferation rate of 12.4%, 16.5%, and 28.9%, respectively, compared with matched nonirradiated controls (p < .05) and did not significantly alter viability relative to the matched nonirradiated controls.
  
  
  CONCLUSIONS
  Light-emitting diode-generated red light can inhibit keloid fibroblast proliferation in a dose-dependent manner without altering viability. Light-emitting diode-generated red light has the potential to contribute to the treatment of keloids and other fibrotic skin diseases and is worthy of further translational and clinical investigation.
authors.affiliation: *Department of Dermatology, University of California at Davis, Sacramento, California; †Dermatology Service, Sacramento VA Medical Center, Mather, California; ‡Department of Dermatology, SUNY Downstate Medical Center, Brooklyn, New York.
authors.forename: Andrew
authors.initials: A
authors.lastname: Mamalis
authors.forename: Jared
authors.initials: J
authors.lastname: Jagdeo
mesh_terms: D049109:Cell Proliferation / Q000528:radiation effects*; D002470:Cell Survival / Q000528:radiation effects*; D002478:Cells, Cultured; D003116:Color; D005347:Fibroblasts / Q000166:cytology / Q000528:radiation effects*; D006801:Humans; D007627:Keloid / Q000473:pathology*; D011829:Radiation Dosage