A series of finely dispersed Y ₂ O ₃ :Eu and YAG:Eu phosphors useful for the enhancement of photodynamic therapy (PDT) of cancer were prepared using the Pechini method and self-propagating high temperature synthesis (SHS). The obtained phosphors can be used in cancer therapy drugs in combination with a photosensitizer which accumulates selectively in tumor tissues. Upon excitation with X-ray irradiation which easily penetrates the organism such phosphors are activated to radiate the visible light with wavelengths required to stimulate the photosensitizer yielding active singlet oxygen which destroys cancer cells. Thus the developed phosphors provide an extension of PDT in the treatment of internal tumors which are inaccessible for activating light from the outside. A detailed characterization of the obtained phosphors was performed to define various types of adsorption centers and the functional groups on their surface, including hydroxyls with different acid-base characteristics and an admixture hydrated carbonate layer which may help in linking with other drugs (photosensitizer and pluronic binder) and is important in respect of biocompatibility. A model describing the composition of acid-base centers with various pK _a values on the surface of the studied materials is suggested on the basis of the obtained results as an approach to study the adjustable modification of various compounds in respect of the compatibility between their ingredients as well as their overall biocompatibility. Y ₂ O ₃ :Eu phosphor prepared via the SHS method was successfully tested for biological (therapeutic) activity which provided an effective destruction of fibroblast cell cultures of Chinese hamster V-79 in combination with a photosensitizer upon X-ray irradiation.

The influence of the stabilizer and thermal treatment on the luminescence and surface properties of ZnS: Mn2+nanosized phosphors has been studied. It has been found that ammonium polyacrylate is the...

The use of targeted drug delivery systems, including those based on selective absorption by certain receptors on the surface of the target cell, can lead to a decrease in the minimum effective dose and the accompanying toxicity of the drug, as well as an increase in therapeutic efficacy. A fullerene C₆₀ conjugate (FA-PVP-C₆₀) with polyvinylpyrrolidone (PVP) as a biocompatible spacer and folic acid (FA) as a targeting ligand for tumor cells with increased expression of folate receptors (FR) was obtained. Using ¹³C NMR spectroscopy, FT-IR, UV-Vis spectrometry, fluorometry and thermal analysis, the formation of the conjugate was confirmed and the nature of the binding of its components was established. The average particle sizes of the conjugate in aqueous solutions and cell culture medium were determined using dynamic light scattering (DLS) and nanoparticle tracking analysis (NTA). The FA-PVP-C₆₀ showed antiradical activity against ^•DPPH, ^•OH and O₂^•−, but at the same time, it was shown to generate ¹O₂. It was found that the conjugate in the studied concentration range (up to 200 μg/mL) is non-toxic in vitro and does not affect the cell cycle. To confirm the ability of the conjugate to selectively accumulate through folate-mediated endocytosis, its uptake into cells was analyzed by flow cytometry and confocal microscopy. It was shown that the conjugate is less absorbed by A549 cells with low FR expression than by HeLa, which has a high level of expression of this receptor.

A series of LaF₃:Ce³⁺ phosphors for application in photodynamic therapy are synthesized using a one-stage solvothermal synthesis. The synthesis conditions; type and quantity of stabilizer; concentration of activator providing the maximum intensity of UV- and X-ray-excited luminescence; lowest size; and highest colloidal stability of the phosphor nanoparticles are found. As a result of this study, the following parameters are determined using cerium content 5% mol. ethanol as the reaction medium for the solvothermal synthesis and polyvinylpyrrolidone as the stabilizer at an optimized amount.

YPO₄:Eu, YVO₄:Eu, and YVPO₄:Eu based phosphors with various Eu(III) activator contents and phosphate-vanadate ratios were synthesized by the self-propagating high-temperature synthesis method. The samples were characterized by scanning electron microscopy, nitrogen sorption, acid-base indicators and photoluminescence. The particle surface features with a finely dispersed structure comprising all the involved elements. The pore structure and the specific surface areas of the samples were different depending on the compositions of the samples. The most finely dispersed sample was YVO₄:Eu samples. The specific surface areas of the YPO₄:Eu samples were 10 to 15 times greater than those of vanadate samples. The phosphors samples had a slightly basic (YVO₄:Eu, YVPO₄:Eu) or slightly acidic (YPO₄:Eu) properties of the surface with different contents of Lewis and Brönsted sites. The differences in the compositions and acid-base state resulted in the difference in the intensity and brightness of the photoluminescence (PL) of the samples. The yttrium-phosphate-vanadate phosphors of the mixed YV_xP_1−xO₄-Eu had higher brightness and PL intensity than those samples with similar phosphate as well as vanadate phosphors.