Permeability of DOPC bilayers under photoinduced oxidation: Sensitivity to photosensitizer

Isabel O L Bacellar (1, 2) , Mauricio S Baptista (1) , Helena C Junqueira (1) , Mark Wainwright (3) , Fabrice Thalmann (2) , Carlos M. Marques (2) , André P Schroder (2)

1 USP - Universidade de São Paulo = University of São Paulo
2 ICS - Institut Charles Sadron
3 LJMU - Liverpool John Moores University

The modification of lipid bilayer permeability is one of the most striking yet poorly understood physical transformations that follow photoinduced lipid oxidation. We have recently proposed that the increase of per-meability of photooxidized 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) bilayers is controlled by the time required by the oxidized lipid species to diffuse and aggregate into pores. Here we further probe this mechanism by studying photosensitization of DOPC membranes by methylene blue (MB) and DO15, a more hydrophobic phenothiazinium photosensitizer, under different irradiation powers. Our results not only reveal the interplay between the production rate and the diffusion of the oxidized lipids, but highlight also the importance of photosensitizer localization in the kinetics of oxidized membrane permeability.

Mots clés: Pore formation; Membrane permeabilization; Phenothiazinium photosensitizers; Model membrane; Lipid photooxidation

Domaines: Matière Molle [cond-mat.soft]

Isabel O L Bacellar, Mauricio S Baptista, Helena C Junqueira, Mark Wainwright, Fabrice Thalmann, et al.. Permeability of DOPC bilayers under photoinduced oxidation: Sensitivity to photosensitizer. Biochimica et Biophysica Acta:Biomembranes, 2018, 1860 (11), pp.2366-2373. ⟨10.1016/j.bbamem.2018.06.001⟩. ⟨hal-02126589⟩