X-ray-induced photodynamic therapy (X-PDT) represents a promising new method of cancer treatment. A novel type of nanoscintillator based on cerium fluoride (CeF₃) nanoparticles (NPs) modified with flavin mononucleotide (FMN) has been proposed. A method for synthesizing CeF₃-FMN NPs has been developed, enabling the production of colloidal, spherical NPs with an approximate diameter of 100 nm, low polydispersity, and a high fluorescence quantum yield of 0.42. It has been demonstrated that CeF₃-FMN NPs exhibit pH-dependent radiation-induced redox activity when exposed to X-rays. This activity results in the generation of reactive oxygen species, which is associated with the scintillation properties of cerium and the transfer of electrons to FMN. The synthesized NPs have been demonstrated to exhibit minimal cytotoxicity towards normal cells (NCTC L929 fibroblasts) but are more toxic to tumor cells (epidermoid carcinoma A431). Concurrently, the synthesized NPs (CeF₃ and CeF₃-FMN NPs) demonstrate a pronounced selective radiosensitizing effect on tumor cells at concentrations of 10⁻⁷ and 10⁻³ M, resulting in a significant reduction in their clonogenic activity, increasing radiosensitivity for cancer cells by 1.9 times following X-ray irradiation at a dose of 3 to 6 Gy. In the context of normal cells, these nanoparticles serve the function of antioxidants, maintaining a high level of clonogenic activity. Functional nanoscintillators on the basis of cerium fluoride can be used as part of the latest technologies for the treatment of tumors within the framework of X-PDT.

An efficient method has been developed for the synthesis of resorcinol–formaldehyde hybrid aerogels with ferrocene subunit fragments embedded in their polymer structure. For gelation preceding the synthesis of aerogels, dioxane was used for the first time as the main reaction solvent. The gels were converted into aerogels using SC-CO₂. The aerogel samples were characterized in detail by Mössbauer spectroscopy, nitrogen adsorption, and atomic absorption spectroscopy. The density of the materials was determined. The iron content in the resulting aerogels varies from 1.5 to 11 wt % (or 5.6–36.3 wt % ferrocene units). The metallocene subunits are present in aerogels in two valence-oxidation states: ferrocene and ferrocenium.

The UV-shielding composite films based on nanocrystalline cellulose (CNC) modified with both CeO₂ and WO₃ nanoparticles were prepared by solvent casting method. In the composites, both CeO₂ and WO₃ nanoparticles showed redox activity under UV-irradiation, and the joint effects of that metal oxides in the composite films were evidenced. The WO₃ nanoparticles provided reversible photochromic properties to the WO₃/CNC film under UV-irradiation while CeO₂ nanoparticles inhibited the photochromic effect. The mechanism of this inhibition in the CeO₂/WO₃/CNC films was investigated using UV–vis and FTIR spectroscopy. The photodegradation of CNC catalyzed by CeO₂ nanoparticles inherent in CeO₂/CNC films was prevented by the addition of WO₃ nanoparticles. The CeO₂/CNC and CeO₂/WO₃/CNC films exhibited strong UV-shielding property. The synthesized photostable UV-shielding CeO₂/WO₃/CNC films with photochromic property which can easily be tuned by the CeO₂ to WO₃ ratio can be useful for various applications, including protection of UV-sensitive dyes and production of UV-shielding packages.

An efficient method has been developed for the synthesis of siloxane aerogels with a hybrid structure built into the polymer structure. At the initial stage, a gel was obtained by polycondensation of tetraethoxysilane and ferrocene-containing alkoxysilanes, catalyzed by BF₃ ⋅ Et₂O in acetone. The transformation of gels into aerogels was performed using supercritical carbon dioxide (SC-CO₂). The aerogel samples were characterized in detail by Mössbauer spectroscopy and nitrogen adsorption methods, and the density of the materials was determined. The iron content in the resulting aerogels varied from 3.6 to 8.7 wt % (or 11.9–28.7 wt % ferrocene units).