title: In vitro and in vivo laser treatments of tattoos: high efficiency and low fluences.
abstract: OBJECTIVE
  To analyze the absorption of tattoo inks related to their in vivo and in vitro behavior under laser irradiation to improve laser-assisted tattoo removal.
  
  
  METHODS
  The absorption of 21 tattoo inks in a wavelength range from 300 to 800 nm was characterized by reflection spectroscopy from samples consisting of inks mixed in gelatin. Tattoo inks were removed in vitro using pulsed laser radiation with different variables, and morphologic analysis of the irradiated areas was performed.
  
  
  METHODS
  An interdisciplinary laser laboratory with a common industrial project with the Spanish company Milesman S.A.
  
  
  METHODS
  One person was voluntarily tattooed with 2 of the studied inks.
  
  
  METHODS
  (1) First approach to the optimum dose for pigment removal in in vitro models. (2) Correlation between the in vitro and in vivo situations at the optimum dose.
  
  
  RESULTS
  Reflection spectroscopy facilitated selection of the most adequate laser wavelengths for tattoo removal. Red, orange, and rose inks were successfully lightened at 532 nm with 0.6 J/cm2; brown at 1064 nm with 0.3 J/cm2; yellow and green at 448 nm with 2.6 J/cm2; and blue at 600 nm with 0.9 J/cm2. Similar colors in in vitro and in vivo tattoos responded with the same efficiency to the laser variables.
  
  
  CONCLUSIONS
  High efficiency is reached in the removal of in vivo tattoos by using an irradiation wavelength at which the percentage of reflection from the pigment is minimal. Under this condition, laser pulses can be used with a low fluence, minimizing adverse effects and clinical time.
authors.affiliation: Departamento de Química Láser, Instituto de Química-Física Rocasolano, Consejo Superior de Investigaciones Científicas, Serrano 119, 28006 Madrid, Spain. c.gomez@iqfr.csic.es
authors.forename: Clara
authors.initials: C
authors.lastname: Gómez
authors.forename: Virginia
authors.initials: V
authors.lastname: Martin
authors.forename: Roberto
authors.initials: R
authors.lastname: Sastre
authors.forename: Angel
authors.initials: A
authors.lastname: Costela
authors.forename: Inmaculada
authors.initials: I
authors.lastname: García-Moreno
mesh_terms: D006801:Humans; D028022:Low-Level Light Therapy / Q000379:methods*; D008954:Models, Biological; D010860:Pigments, Biological; D013653:Tattooing
chemical_list: D010860:Pigments, Biological