Features of Luminescent Properties of Alginate Aerogels with Rare Earth Elements as Photoactive Cross-Linking Agents

Luminescent aerogels based on sodium alginate cross-linked with ions of rare earth elements (Eu3+, Tb3+, Sm3+) and containing phenanthroline, thenoyltrifluoroacetone, dibenzoylmethane, and acetylacetone as ligands introduced into the matrix during the impregnation of alginate aerogels (AEG), were obtained for the first time in a supercritical carbon dioxide medium. The impregnation method used made it possible to introduce organically soluble sensitizing ligands into polysaccharide matrices over the entire thickness of the sample while maintaining the porous structure of the aerogel. It is shown that the pore size and their specific area are 150 nm and 270 m2/g, respectively. Moreover, metal ions with content of about 23 wt.%, acting as cross-linking agents, are uniformly distributed over the thickness of the sample. In addition, the effect of sensitizing ligands on the luminescence intensity of cross-linked aerogel matrices is considered. The interaction in the resulting metal/ligand systems is unique for each pair, which is confirmed by the detection of broad bands with individual positions in the luminescence excitation spectra of photoactive aerogels.

Development of resistance to 5-fluorouracil affects membrane viscosity and lipid composition of cancer cells

The investigations reported here were designed to determine whether the bulk plasma membrane is involved in mechanisms of acquired resistance of colorectal cancer cells to 5-fluorouracil (5-FU). Fluorescence lifetime imaging microscopy (FLIM) of live cultured cells stained with viscosity-sensitive probe BODIPY 2 was exploited to non-invasively assess viscosity in the course of treatment and adaptation to the drug. In parallel, lipid composition of membranes was examined with the time-of-flight secondary ion mass spectrometry (ToF-SIMS). Our results showed that a single treatment with 5-FU induced only temporal changes of viscosity in 5-FU sensitive cells immediately after adding the drug. Acquisition of chemoresistance was accompanied by persistent increase of viscosity, which was preserved upon treatment without any changes. Lipidomic analysis revealed that the resistant cells had a lower level of monounsaturated fatty acids and increased sphingomyelin or decreased phosphatidylcholine in their membranes, which partly explain increase of the viscosity. Thus, we propose that a high membrane viscosity mediates the acquisition of resistance to 5-FU.

[POPULATION AND CLUSTER APPROACH TO ASSESSMENT OF REPRODUCTIVE HEALTH OF WOMEN]

The purpose of this study was to explore the possibility of using a population approach to assessing the risk of reproductive health disorders in women of childbearing age. We observed 240 clinically healthy women aged 20 to 43 years, half of them lived in the Middle Black Earth region of Russia, and 120 women lived in Tajikistan. The study identified population differences in women with different ethnic backgrounds and regions of residence according to a set of genetic, hormonal, and immune signs. All women underwent venous blood sampling for the purpose of HLA typing by molecular genetic analysis and determining the range of normative values ​​of hormonal and immune status parameters. DNA samples were obtained from peripheral blood lymphocytes using reagent kits and a protocol for isolating DNA from various biological materials from DLAtomTM DNAPrep 100 (Russia). Hormonal status was studied in terms of follicle-stimulating hormone, luteinizing hormone, prolactin, estradiol, progesterone, 17-OH-progesterone; Thyroid hormones - thyroid-stimulating hormone, total triiodothyronine, total thyroxine; Androgens - testosterone, dihydroepiandrosterone; Steroid hormone-cortisol. In order to exclude the variability of the data, the examination was carried out on the 3-5th days of the menstrual cycle: luteinizing hormone, follicle-stimulating hormone, estradiol, prolactin, testosterone and on the 20-22nd Day of the progesterone cycle. Statistical data processing was carried out on the basis of SPSS programs and included descriptive and comparative nonparametric statistics, discriminant, regression analysis, one - factorial analysis of variance, calculation of 95% confidence intervals, construction of ROC curves. The study included the determination of allelic variants at the three loci of the HLA-D genes (HLA-DRB1, HLA-DQA1, HLA-DQB1) controlling the immune response. Population differences in the locus of the HLA-DRB1 gene were determined. The HLA-DRB1 * 08 and HLA-DRB1 * 12 alleles are found in the Russian women's population, and the HLA-DRB1 * 04 and HLA-DRB1 * 17 alleles are more reliably detected in the Tajik women's population, while the HLA-DRB1 * 04 allele Is associated with a higher incidence of miscarriage. The population characteristics of the HLA-DQA1 gene locus were also established. In the group of women of the Russian population, the incidence of HLA-DQA1 * 0101 and HLA-DQA1 * 0103 alleles is significantly higher, of which the former is associated with protective properties for reproductive pathology, and the latter, on the contrary, with miscarriage. At the same time, the alleles HLA-DQA1 * 0201 and HLA-DQA1 * 0301 were significantly more often detected in the compared with the population of Tajik women. As in the previous case, for the HLA-DQA1 * 0201 allele reproductive health disorders are not characteristic, and in the case of the HLA-DQA1 * 0301 allele they accompany it. Our studies have revealed that there are differences between the populations of Russian and Tajik women in a number of parameters of the hormonal and immune status, as well as at the level of allelic variants of genes that control the immune response. The population approach, based on the use of discriminant analysis, is a highly effective way of grouping women according to their reproductive health status and the risk factors that caused reproductive damage. The risk factors that caused the reproductive failure are different in combination and manifestation in the populations of Russian and Tajik women, except for the adverse allelic variants of the HLA-DRB1 * 04 and HLA-DQA1 * 0103 genes, which are the same in both populations. The obtained data also show that in different populations in the evaluation of reproductive health a differentiated approach is needed both to establish physiological norms in these categories of parameters and to assess the reproductive health of women.

Femtosecond Nanostructuring of Glass with Optically Trapped Microspheres and Chemical Etching

Laser processing with optically trapped microspheres is a promising tool for nanopatterning at subdiffraction-limited resolution in a wide range of technological and biomedical applications. In this paper, we investigate subdiffraction-limited structuring of borosilicate glass with femtosecond pulses in the near-field of optically trapped microspheres combined with chemical postprocessing. The glass surface was processed by single laser pulses at 780 nm focused by silica microspheres and then subjected to selective etching in KOH, which produced pits in the laser-affected zones (LAZs). Chemical postprocessing allowed obtaining structures with better resolution and reproducibility. We demonstrate production of reproducible pits with diameters as small as 70 nm (λ/11). Complex two-dimensional structures with 100 nm (λ/8) resolution were written on the glass surface point by point with microspheres manipulated by optical tweezers. Furthermore, the mechanism of laser modification underlying selective etching was investigated with mass spectrum analysis. We propose that the increased etching rate of laser-treated glass results from changes in its chemical composition and oxygen deficiency.