SCINT 2017 - 14th Int. Conference on Scintillating Materials and their Applications

LuAG:Pr3+ - BASED NANOHYBRID SYSTEMS FOR SINGLET OXYGEN GENERATION

20 Sept 2017, 10:00

1h

Congress Centre "Le Majestic"

Poster presentation P6_Nanomaterials Poster Session 2

Speaker

Kseniya Popovich (Czech Technical University in Prague, Faculty of Nuclear Sciences and Physical Engineering)

Description

With LuAG:RE³⁺ (RE = rare-earth elements) single crystal and fiber applications in many fields of scintillator industry, including high-energy particle physics, medical imaging and security measures [1], there is a growing interest in the LuAG:Re³⁺ powders. Due to the luminescence properties and very high chemical stability, such powders may be used as a light-emitting core of the nanocomposite material for X-ray induced photodynamic therapy (PDTX) [2]. PDTX uses tumor-destroying agents based on the nanoparticles (NP) conjugated with photosensitizer (PS) molecules. The agent accumulates preferentially in the target cells; subsequently, the external X-ray irradiation excites the scintillating NP, emitting secondary radiation, which activates the PS molecules. Their deexcitation via non-radiative energy transfer (ET) leads to the production of the reactive oxygen species, where the singlet oxygen is believed to be the most cytotoxic one [3].

Due to the suitable luminescent properties, especially the overlap of Pr³⁺ emission and protoporpyrin IX (PpIX) absorption bands, LuAG:Pr³⁺ may be a good candidate for a light-emitting core of the PDTX agent. In this work, we present a concept of preparation of the singlet oxygen producing LuAG:Pr³⁺@SiO₂-PpIX nanocomposites for PDTX application. LuAG:Pr³⁺ nanoparticles with the average size of about 25 nm were prepared using photo-induced method [2]. Subsequently, the surface coating procedure with SiO₂ amorphous layer was performed via combined two-step sol-gel/dense liquid coating process. Finally, NPs were conjugated with a photosensitizer molecule (PpIX). Morphological characteristics of the materials were obtained from the X-ray diffraction analysis (XRD) and transmission electron microscopy (TEM). Energy transfer (ET) and luminescent properties of the nanocomposites were studied by radioluminescence (RL) and photoluminescence (PL) spectroscopies.

Acknowledgement:

This work has been supported by the Czech Science Foundation, project GA17-06479S, and by the Grant Agency of the Czech Technical University in Prague, grant No. SGS17/195/OHK4/3T/14.

References:

[1] Diehl, S. et al. (2015). Journal of Physics: Conference Series 587, 012067.

[2] Bárta, J. et al. (2012). Journal of Materials Chemistry 22, 16590 - 16597.

[3] Weishaupt, K. R. et al. (1976) Cancer Research 36 (7), 2326 - 2329.

Presentation materials

poster_Kseniya_Popovich.pdf