BaGdF5 Nanophosphors Doped with Different Concentrations of Eu3+ for Application in X-ray Photodynamic Therapy

Abstract

X-ray photodynamic therapy (XPDT) has been recently considered as an efficient alternative to conventional radiotherapy of malignant tissues. Nanocomposites for XPDT typically consist of two components—a nanophosphor which re-emits X-rays into visible light that in turn is absorbed by the second component, a photosensitizer, for further generation of reactive oxygen species. In this study, BaGdF5 nanophosphors doped with different Eu:Gd ratios in the range from 0.01 to 0.50 were synthesized by the microwave route. According to transmission electron microscopy (TEM), the average size of nanophosphors was ~12 nm. Furthermore, different coatings with amorphous SiO2 and citrates were systematically studied. Micro-CT imaging demonstrated superior X-ray attenuation and sufficient contrast in the liver and the spleen after intravenous injection of citric acid-coated nanoparticles. In case of the SiO2 surface, post-treatment core–shell morphology was verified via TEM and the possibility of tunable shell size was reported. Nitrogen adsorption/desorption analysis revealed mesoporous SiO2 formation characterized by the slit-shaped type of pores that should be accessible for methylene blue photosensitizer molecules. It was shown that SiO2 coating subsequently facilitates methylene blue conjugation and results in the formation of the BaGdF5: 10% Eu3+@SiO2@MB nanocomposite as a promising candidate for application in XPDT.

Photo- and X-ray Induced Cytotoxicity of CeF₃-YF₃-TbF₃ Nano-Particle- Polyvinylpyrrolidone –“Radachlorin” Composites for Combined Photodynamic Therapy

“…However, the work demonstrates conjugation of Tb 3+ :LaF3 nanoparticles with Rose Bengal via electrostatic interaction of negatively charger functional groups of Rose Bengal photosensitizer and positively charged Tb 3+ :LaF3 nanoparticle surface due to Fvacancies on the surface. In its turn, the Eu 3+ :BaGdF5/SiO2 core/shell nanoparticles loaded with methylene blue photosensitizer demonstrated their efficiency in X-ray induced PDT due to the porous nature of SiO2 shell [25].…”

Photo- and X-ray Induced Cytotoxicity of CeF3-YF3-TbF3 Nanoparticle-Polyvinylpyrrolidone—“Radachlorin” Composites for Combined Photodynamic Therapy

“…However, the work demonstrates the conjugation of Tb 3+ :LaF 3 nanoparticles with Rose Bengal via the electrostatic interaction of negatively charged functional groups of Rose Bengal photosensitizer and the positively charged Tb 3+ :LaF 3 nanoparticle surface due to Fvacancies on the surface. In turn, the Eu 3+ :BaGdF 5 /SiO 2 core/shell nanoparticles loaded with methylene blue photosensitizer demonstrated their efficiency in X-ray-induced PDT due to the porous nature of the SiO 2 shell [31].…”

Single-Stage Microfluidic Synthesis Route for BaGdF5:Tb3+-Based Nanocomposite Materials: Synthesis, Characterization and Biodistribution

“…The morphology, particle size, and luminescent properties of BaGdF 5 nanophosphors doped with different rare-earth elements have been previously discussed in refs [13][14][15][16][17][18][19][20]. In particular, D. Yang et al have reported sub-10 nm BaGdF 5 :Yb 3+ /Tm 3+ up-conversion nanoparticles (NPs) synthesized at 300 • C, stabilized by oleic acid and subsequently loaded by doxorubicin to enhance its anti-cancer activity [17].…”