title: Increased fibroblast proliferation and activity after applying intense pulsed light 800-1200 nm.
abstract: OBJECTIVE
  Light devices emitting near infrared have been shown to be highly effective for the skin rejuvenation but biochemical and molecular mechanism or optimum dose treatment are not well-known. In our study we try to elucidate why systems emitting near infrared produce skin improvement such as fibroblasts proliferation, increase in gene expression or extracellular matrix (ECM) protein production.
  
  
  METHODS
  1BR3G human skin fibroblasts were used to test the effects of an intense pulsed light device emitting with an 800-1200 nm filter (MiniSilk FT manufactured by Deka(®)). In our protocol, fibroblasts were irradiated twice successively with a 10 Hz frequency, with a total fluence up to 60 J/cm(2) for 15s each pass. After incubating for 48 h, fibroblasts were harvested from the culture plates to test cell proliferation by flow cytometer. To determine changes in gene expression (mRNA levels for collagen types I and III and metalloproteinase 1 (MMP-1)) and protein production (hyaluronic acid, versican and decorin) tests were performed after irradiation.
  
  
  RESULTS
  After 48 h irradiation, 1BR3G human skin fibroblasts were observed to proliferate at a fast rate. The study of ECM macromolecules production using ELISA showed an increase of hyaluronic acid and versican production but no changes were observed for decorin. With RT-PCR assays, an increase in mRNA for collagen type I, type III and MMP-1 were observed.
  
  
  CONCLUSIONS
  Intense pulsed light emitting near infrared applied in vitro cultured cells increases fibroblasts proliferation and activity, which can be a possible mechanism of action for these devices in aging skin treatment.
authors.affiliation: Section of Human Anatomy and Embriology, Universidad Rey Juan Carlos, Madrid, Spain. Electronic address: esther.cuerda@urjc.es.
authors.forename: E
authors.initials: E
authors.lastname: Cuerda-Galindo
authors.affiliation: Section of Human Anatomy and Embriology, Universidad Rey Juan Carlos, Madrid, Spain.
authors.forename: G
authors.initials: G
authors.lastname: Díaz-Gil
authors.affiliation: Section of Human Anatomy and Embriology, Universidad Rey Juan Carlos, Madrid, Spain.
authors.forename: M A
authors.initials: MA
authors.lastname: Palomar-Gallego
authors.affiliation: Section of Human Anatomy and Embriology, Universidad Rey Juan Carlos, Madrid, Spain.
authors.forename: R
authors.initials: R
authors.lastname: Linares-GarcíaValdecasas
mesh_terms: D002460:Cell Line; D049109:Cell Proliferation / Q000502:physiology / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D005109:Extracellular Matrix / Q000502:physiology* / Q000528:radiation effects; D016326:Extracellular Matrix Proteins / Q000378:metabolism*; D005347:Fibroblasts / Q000166:cytology / Q000502:physiology* / Q000528:radiation effects; D005786:Gene Expression Regulation / Q000502:physiology / Q000528:radiation effects; D006801:Humans; D007259:Infrared Rays; D008027:Light; D010775:Photic Stimulation / Q000379:methods*; D011829:Radiation Dosage; D012867:Skin / Q000166:cytology* / Q000528:radiation effects; D012879:Skin Physiological Phenomena / Q000528:radiation effects*
chemical_list: D016326:Extracellular Matrix Proteins
keywords: Collagen; Decorin; Fibroblast; Hyaluronic acid; Intense pulsed light; Metalloproteinase; Versican