Marco Marazzi
University of Lorraine−Nancy & CNRS, France
Title: DNA photosensitization: irreversible lesions caused by non-covalent binding with organic dyes
Biography
Biography: Marco Marazzi
Abstract
Although diverse DNA photostability mechanisms exist, organic dyes in the vicinity of DNA can induce damages through indirect light absorption. Hence, understanding the underlying mechanisms involved in photosensitized DNA damage is crucial to describe and possibly anticipate photobiological risks, as well as to design anticancer phototherapies. Here, we present the results concerning our latest studies on different reactivities induced by common organic dyes, through multiscale molecular modeling techniques coupled to spectroscopy experiments. Especially, the photochemistry of benzophenone – a paradigmatic DNA photosensitizer – and its implications in the competitive processes of hydrogen abstraction and energy transfer to DNA will be described. Electron transfer is also considered by the interaction of DNA with two fluorescent dyes widely used in cellular biology: nile blue and nile red. Finally, the potentialities of a very recently sinthesized novel carbazole in photosensitizing DNA through two-photon absorption will be reported. Especially, it will be shown how it can induce DNA strand break upon photoionization with the production of a solvated electron. The main advantage is the low-energy (infra-red) irradiation required also in the absence of molecuar oxygen, i.e. a prodrug of great interest for the potential treatment of solid tumors.