Photoinduced modifications triggered by rose bengal in bioinspired and in vitro systems

Abstract

Cancer is currently one of the top diseases in the ranking of deaths in the world. Traditional treatments such as chemotherapy and radiotherapy cause severe side effects, demanding new therapeutic strategies. In this context, photodynamic therapy (PDT) is a non-invasive technique that stands out owing to its effectiveness in reducing tumor cell viability. Herein, we shall evaluate the photodynamic efficiency of Rose Bengal (RB) photosensitizer (FS) in the in vitro culture of cancer cells. This efficiency will be quantified via flow cytometry, which will also determine the cell death pathways (apoptosis vs necrosis) triggered. Cell membrane models based on Langmuir films will be used to unravel the interaction mechanisms and the effects of the photoinduced lipid oxidation responsible for cell toxicity. Langmuir films will be produced from the lipid extract of cancer cells and characterized by surface pressure vs. area (À-A isotherms) in subphase containing different concentrations of RB. In addition to À-A isotherms, ellipsometry technique will be applied to the Langmuir films to elucidate the reaction mechanisms between the cell membrane and the FS RB. At the end of this project, we aim to correlate the discoveries made at molecular scale with photodynamic efficiency in complex systems involving the in vitro culture of cancer cells. This BEPE proposal is part of the master's degree project (2021/14020-0) entitled "Photosensitization of colorectal carcinoma model systems mediated by the xanthene rose bengal", which has been carried out at the FCL-UNESP, Assis. (AU)