Interactions between YVO4 and cucurbit[n]uryls and insertion of photosensitizing molecules with potential application in photodynamic therapy

• Grant number: 18/13586-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2018
• End date: December 01, 2020
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
• Principal Investigator: Paulo Cesar de Sousa Filho
• Grantee: Giulia Rinaldi
• Host Institution: Instituto de Química (IQ). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated scholarship(s): 19/24955-6 - Surface and structure characterization of YVO4-cucurbit[n]uril multifunctional nanoscale platforms, BE.EP.IC

Abstract

Photodynamic therapy consists of light-stimulated treatments with the purpose of selective destruction of tissues or microorganisms using photosensitizing agents capable of triggering the localized formation of reactive species. Nevertheless, in situ monitoring of the thermal state of the tissues undergoing photodynamic therapy is still a great challenge, since the unintentional increase in temperature can reduce the effectiveness of the treatment and generate adverse effects. In this sense, rare earth nanomaterials have very promising luminescent properties for remote determination of temperature, which is known as optical nanotermometry. The use of luminescent nanoparticles such as YVO4:Ln3+ (Ln=Eu3+, Yb3+/Er3+) in photodynamic therapy can therefore help to precisely monitor the temperature with high spatial resolution, leading to the improvement of this type of treatment. Hence, this project aims at combining photosensitizing dyes with YVO4:Ln3+ luminescent nanoparticles with thermal response to obtain structures that act simultaneously as nanotermometers and as active systems in photodynamic therapy. For this, anchoring of cucurbituril molecules (CB[n], n=6 ou 7) on the surface of YVO4:Ln3+ nanoparticles will be previously performed. Because of their molecular characteristics, CB[n]s may not only to interact strongly with the charged surface of nanoparticles, but also host photosensitizing molecules as, for instance, inclusion complexes. Thus, we intend to establish the methodologies for the functionalisation of YVO4:Ln3+ nanoparticles with CB[n]s for further immobilization of commercial dyes (methylene blue, toluidine blue O and DIPh-BODIPY) to obtain systems that combine photodynamic activity and nanothermometric response.