Environment effects on photosensitizer properties and energy transfer processes studied by means of QMMM approaches

• Grant number: 21/09841-4
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate (Direct)
• Effective date (Start): March 01, 2022
• Effective date (End): February 28, 2023
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Paula Homem-de-Mello
• Grantee: Jhonathan Rosa de Souza
• Supervisor: Carles Eduard Curutchet Barat
• Host Institution: Centro de Ciências Naturais e Humanas (CCNH). Universidade Federal do ABC (UFABC). Ministério da Educação (Brasil). Santo André , SP, Brazil
• Research place: Universitat de Barcelona (UB), Spain
• Associated to the scholarship: 18/25576-6 - Studies on photophysical and energy transfer processes of photosensibilizers with emphasis in photodynamic therapy: an approach of first principles, BP.DD

Abstract

Photodynamic therapy (PDT) consists of applying light with precise energy in the presence of a photosensitizer (PS) and molecular oxygen to promote cell death. Since the efficacy of PS to be employed in PDT will depend, among other factors, on the transfer of energy to molecular oxygen, longer excited-state lifetimes and the environmental effects may favor this process. Here we propose to study the PS molecules using both quantum mechanics, and molecular dynamics approaches to evaluate structural and electronic properties of pyranoflavylium cations and porphyrin-like compounds, as well as the dynamics of interaction with molecular oxygen in different environments. In collaboration with Prof. Carles Curutchet, from the University of Barcelona, we will develop a protocol to study the interaction between oxygen and photosensitizers using hybrid quantum-classical methods. Our preliminary studies indicate significant interactions between PS and solvent molecules, once it was observed some solvatochromic effects in the spectra already simulated, even leading to the formation of persistent long-range interactions between these species. In this regard, Prof. Curutchet developed polarizable quantum-classical methods to adequately describe such interactions and the fundamental electronic properties that determine the efficiency of the studied photosensitizers. Furthermore, Prof. Curutchet has experience in simulating energy transfer processes in biosystems, a skill that can help investigate PDT processes. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

SOUZA, JHONATHAN R.; CURUTCHET, CARLES; AOTO, YURI A.; HOMEM-DE-MELLO, PAULA. Benchmarking DFT functionals for photophysics of pyranoflavylium cations. JOURNAL OF MOLECULAR GRAPHICS & MODELLING, v. 122, p. 11-pg., 2023-03-31. (17/21199-0, 21/09841-4, 18/25576-6)