title: Reducing the Harmful Effects of Infrared Radiation on the Skin Using Bicosomes Incorporating β-Carotene.
abstract: OBJECTIVE
  In this work the effect of infrared (IR) radiation, at temperatures between 25 and 30°C, on the formation of free radicals (FRs) in the skin is studied. Additionally, the influence of IR radiation at high temperatures in the degradation of skin collagen is evaluated. In both experiments the protective effect against IR radiation of phospholipid nanostructures (bicosomes) incorporating β-carotene (Bcb) is also evaluated.
  
  
  METHODS
  The formation of FRs in skin under IR exposure was measured near physiological temperatures (25-30°C) using 5,5-dimethyl-1-pyrroline-N-oxide spin trap and electron paramagnetic resonance (EPR) spectroscopy. The study of the collagen structure was performed by small-angle X-ray scattering using synchrotron radiation.
  
  
  RESULTS
  EPR results showed an increase in the hydroxyl radical in the irradiated skin compared to the native skin. The skin collagen was degraded by IR exposure at high temperatures of approximately 65°C. The treatment with Bcb reduced the formation of FRs and kept the structure of collagen.
  
  
  CONCLUSIONS
  The formation of FRs by IR radiation does not depend on the increase of skin temperature. The decrease of FRs and the preservation of collagen fibers in the skin treated with Bcb indicate the potential of this lipid system to protect skin under IR exposure.
authors.affiliation: Institute of Advanced Chemistry of Catalonia (IQAC-CSIC), Barcelona, Spain.
authors.forename: Estibalitz
authors.initials: E
authors.lastname: Fernández
authors.forename: Lluís
authors.initials: L
authors.lastname: Fajarí
authors.forename: Gelen
authors.initials: G
authors.lastname: Rodríguez
authors.forename: Mercedes
authors.initials: M
authors.lastname: Cócera
authors.forename: Verónica
authors.initials: V
authors.lastname: Moner
authors.forename: Lucyanna
authors.initials: L
authors.lastname: Barbosa-Barros
authors.forename: Christina S
authors.initials: CS
authors.lastname: Kamma-Lorger
authors.forename: Alfonso
authors.initials: A
authors.lastname: de la Maza
authors.forename: Olga
authors.initials: O
authors.lastname: López
mesh_terms: D003094:Collagen / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods; D005609:Free Radicals / Q000037:antagonists & inhibitors / Q000378:metabolism; D006801:Humans; D007259:Infrared Rays / Q000009:adverse effects*; D049329:Nanostructures / Q000008:administration & dosage* / Q000737:chemistry; D010743:Phospholipids / Q000008:administration & dosage* / Q000737:chemistry; D012867:Skin / Q000187:drug effects* / Q000378:metabolism / Q000528:radiation effects*; D019207:beta Carotene / Q000008:administration & dosage*
chemical_list: D005609:Free Radicals; D010743:Phospholipids; D019207:beta Carotene; D003094:Collagen