title: Comparing the mode of action of intraocular lutein-based dyes with synthetic dyes.
abstract: OBJECTIVE
  To investigate and compare the mechanism by which lutein-based and synthetic intraocular dyes interact with their target membranes during ophthalmic surgeries.
  
  
  METHODS
  Surrogate membrane models were used in order to simulate the different intraocular membranes: internal limiting membrane (ILM), vitreous, anterior capsule (AC), and epiretinal membrane (ERM). Different lutein-based dyes, such as Phacodyne, Retidyne, Retidyne Plus, and Vitreodyne were tested, as well as Trypan Blue (TB), Indocyanine Green (ICG), Brilliant Blue (BB), and Triamcinolone Acetonide (TA). The interactions between the film components occurring at the air-water interface were investigated with surface pressure-area isotherms and polarization modulation infrared reflection-absorption spectroscopy (PM-IRRAS).
  
  
  RESULTS
  With the exception of TA and ICG, none of the tested dyes revealed toxicity to the analyzed membranes. The interaction of TA with the vitreous model affected deeply the biointerface structure of the model. A significant condensation of the monolayer is noted when ICG contacted with ILM by the isotherms or even a solubilization of part of the monolayer toward the aqueous subphase. Retidyne Plus may provide the fluidization of the membrane, but maintains intact the structure of proteins present in the model.
  
  
  CONCLUSIONS
  The present study demonstrates for the first time that lutein-based dyes interact through a physical mechanism of action with membrane models of structures present in human eye. On the other hand, the chemical interaction of synthetic dyes TA and ICG resulted in an alteration of the membrane models.
authors.affiliation: Department of Social Pharmacy, College of Pharmacy, University of Lisbon, Lisbon, Portugal Department of Ophthalmology, Escola Paulista de Medicina, Federal University of São Paulo (Unifesp), São Paulo, Brazil.
authors.forename: Diogo
authors.initials: D
authors.lastname: Sousa-Martins
authors.affiliation: Department of Earth and Exacts Sciences, Federal University of São Paulo (Unifesp), Diadema, São Paulo, Brazil.
authors.forename: Luciano
authors.initials: L
authors.lastname: Caseli
authors.affiliation: Department of Social Pharmacy, College of Pharmacy, University of Lisbon, Lisbon, Portugal.
authors.forename: Mafalda C
authors.initials: MC
authors.lastname: Figueiredo
authors.affiliation: Department of Social Pharmacy, College of Pharmacy, University of Lisbon, Lisbon, Portugal.
authors.forename: Claudia
authors.initials: C
authors.lastname: Sa E Cunha
authors.affiliation: Department of Social Pharmacy, College of Pharmacy, University of Lisbon, Lisbon, Portugal.
authors.forename: Helder
authors.initials: H
authors.lastname: Mota-Filipe
authors.affiliation: Department of Ophthalmology, Escola Paulista de Medicina, Federal University of São Paulo (Unifesp), São Paulo, Brazil.
authors.forename: Acácio
authors.initials: A
authors.lastname: Souza-Lima
authors.affiliation: Department of Ophthalmology, Escola Paulista de Medicina, Federal University of São Paulo (Unifesp), São Paulo, Brazil.
authors.forename: Rubens
authors.initials: R
authors.lastname: Belfort
authors.affiliation: Department of Ophthalmology, Escola Paulista de Medicina, Federal University of São Paulo (Unifesp), São Paulo, Brazil.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Rodrigues
authors.affiliation: Department of Ophthalmology, Escola Paulista de Medicina, Federal University of São Paulo (Unifesp), São Paulo, Brazil.
authors.forename: Mauricio
authors.initials: M
authors.lastname: Maia
mesh_terms: D000867:Anterior Chamber / Q000187:drug effects; D001485:Basement Membrane / Q000187:drug effects; D004396:Coloring Agents / Q000494:pharmacology*; D019773:Epiretinal Membrane / Q000188:drug therapy; D005123:Eye / Q000187:drug effects*; D006801:Humans; D014975:Lutein / Q000494:pharmacology*; D008567:Membranes, Artificial; D008954:Models, Biological; D009883:Ophthalmic Solutions / Q000494:pharmacology*; D014222:Triamcinolone Acetonide; D014822:Vitreous Body / Q000187:drug effects
chemical_list: D004396:Coloring Agents; D008567:Membranes, Artificial; D009883:Ophthalmic Solutions; D014222:Triamcinolone Acetonide; D014975:Lutein
keywords: Langmuir films; intraocular membranes; lutein-based dyes; synthetic dyes