On the photoinduced modifications of giant unilamellar vesicles containing Rose Bengal

• Grant number: 19/20897-1
• Support type: Scholarships abroad - Research Internship - Scientific Initiation
• Effective date (Start): December 08, 2019
• Effective date (End): March 07, 2020
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Pedro Henrique Benites Aoki
• Grantee: Bryan Lucas Alfenas Borges
• Supervisor abroad: Carlos Manuel Venancio Marques Serra
• Home Institution: Faculdade de Ciências e Letras (FCL-ASSIS). Universidade Estadual Paulista (UNESP). Campus de Assis. Assis , SP, Brazil
• Local de pesquisa : Institut Charles Sadron (ICS), France
• Associated to the scholarship: 19/03650-2 - Lipid photo-oxidation mediated by the xanthene Rose Bengal in healthy and tumor cell model systems based on Lamgmuir films, BP.IC

Abstract

The photodynamic therapy (PDT) is an emerging therapeutic modality, clinically approved and minimally invasive, which has called great attention for the treatment of carcinomas. The method is based on the controlled administration of a photosensitizer (PS), which induces the singlet oxygen (1O2) formation, an oxidizing agent capable of causing necrosis or apoptosis in cancer cells. It is known that cell membranes and especially unsaturated phospholipids are the major targets of 1O2. However, the underlying effects of photoinduced oxidation over self-assembled phospholipid structures are not yet completely understood. Herein, we shall use giant unilamellar vesicles (GUVs) of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and 1,2-dioleoyl- glycero-3-phospho-L-serine (DOPS) as cell membrane models to investigate the interaction of rose bengal (RB) PS and the effects of photoinduced lipid oxidation. RB belongs to the xanthene family and presents high quantum yield in 1O2 generation. GUVs will be prepared using Gel-Assisted Formation method and exposed to different concentrations of RB characterized by optical microscopies. After the incorporation of RB, the PS will be photoactivated to evaluate the effects of lipid oxidation on the physicochemical properties of the membrane, which may include the increase of the mean molecular area occupied by the lipids and pore opening. This BEPE proposal is part of the scientific initiation project (2019/03650-2) entitled "Lipid photo-oxidation mediated by the xanthene Rose Bengal in healthy and tumor cell model systems based on Langmuir films", which has been carried out at the FCL-UNESP, Assis.