Photo-oxidation in biomimetic lipid membranes: from molecular-level interactions to the impact on photomedicine

• Grant number: 14/17260-8
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: December 01, 2014
• End date: June 30, 2015
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Osvaldo Novais de Oliveira Junior
• Grantee: Pedro Henrique Benites Aoki
• Host Institution: Instituto de Física de São Carlos (IFSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Associated research grant: 13/14262-7 - Nanostructured films from biologically-relevant materials, AP.TEM
• Associated scholarship(s): 15/03441-3 - Combining Raman Spectroscopy (RS) and advanced computational methods to address radiation-induced modifications in human tumour cells, BE.EP.PD

Abstract

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.