Lipid hydroperoxidation, a natural metabolic byproduct of life with oxygen under light, is a prominent oxidation reaction in photomedicine. The effects from oxidation on the fate of lipid membranes, however, remain largely unknown. This research proposal aims at investigating molecular and microscopic effects of oxidation in lipid membranes induced by the action of photosensitizers. Oxidation will be studied in biological membrane mimetic systems based on Langmuir monolayers and giant unilamellar vesicles (GUVs). In addition to the usual measurements of surface pressure, the Langmuir films combined with polarization- modulated infrared reflection adsorption spectroscopy (PM-IRRAS) will provide information about mechanisms of the lipid membrane oxidation at the molecular level. Complementary, the microscopic effects of oxidation will be observed in GUVs and characterized by fluorescence and confocal microscopy. Other techniques such as micro-Raman scattering, fluorescence and UV-Vis absorption will be used as supplementary tools for studying the mechanisms involved in lipid oxidation in Langmuir films and GUVs.
News published in Agência FAPESP Newsletter about the scholarship: