C-phycocyanin (C-PC) is the main component of water-soluble light-harvesting complexes (phycobilisomes, PBS) of cyanobacteria. PBS are involved in the absorption of quantum energy and the transfer of ...electronic excitation energy to the photosystems. A specific environment of C-PC chromophoric groups is provided by the protein matrix structure including protein–protein contacts between different subunits. Registration of C-PC spectral characteristics and the fluorescence anisotropy decay have revealed a significant pH influence on the chromophore microenvironment: at pH 5.0, a chromophore is more significantly interacts with the solvent, whereas at pH 9.0 the chromophore microenvironment becomes more viscous. Conformations of chromophores and the C-PC protein matrix have been studied by Raman and infrared spectroscopy. A decrease in the medium pH results in changes in the secondary structure either the C-PC apoproteins and chromophores, the last one adopts a more folded conformation.
Antimicrobial therapy, especially inactivation of multi-antibiotic-resistant strains, requires creating new approaches for drug action and targeted delivery in different environmental conditions. In ...this work, detonation nanodiamonds (DNDs) were used to deliver polycationic zinc phthalocyanines to E. coli cells. It is shown that in aqueous solutions, zinc phthalocyanines with cholinyl peripheral substituents form complexes with negatively charged DND based on electrostatic interactions. About 40–70 phthalocyanine molecules can bind to a single DND particle, depending on the number of charged groups of the dye molecule. During the complex formation, quenching of phthalocyanine fluorescence and a decrease in its ability to generate reactive oxygen species were observed. In the presence of bacterial cells, phthalocyanine left the complex and induced a photodynamic effect, the magnitude of which depended on the phthalocyanine charge, the molarity of the buffer solution, and the stoichiometry of the phthalocyanine-DND complex. It was found that at physiological values of the ionic strength of the solution, the photodynamic effect of phthalocyanine with a charge of 8+ in combination with a DND is higher than that of the initial phthalocyanine. Thus, nanodiamonds are a promising platform for the delivery of photosensitizers in antimicrobial therapy.
•Polycationic Pcs form hybrid complex (HC) with negatively charged DND.•HCs with Pc:DND > 10 are positively charged and bind to bacterial cell wall.•Pcs are released from the HC due to interaction with bacterial cell.•HC formation enhances photodynamic activity of Pc in highly buffered solutions.
Hybrid complexes of fluorescent nanoparticles and tetrapyrrole dyes are currently considered as promising third-generation photosensitizers for photodynamic therapy, including cancer treatment. Using ...nanoparticles as a platform for delivery of photosensitizers to target cells can increase the efficiency of photodynamic action. In this work, we synthesized a complex of polymer-coated CdSe/ZnS quantum dots, substituted phthalocyanines and human transferrin. Such complexes effectively enter human epidermoid carcinoma cells (A431) due to transferrin-mediated endocytosis and are localized in the perinuclear compartment. We observed an efficient excitation energy transfer from the quantum dot to phthalocyanine in the cells, which indicates stability of the complex upon its internalization. It was shown that the photodynamic activity of hybrid complexes covalently bonded to transferrin is 15% higher than the activity of unmodified hybrid complexes. Our results confirm the feasibility of using fluorescent nanoparticles to enhance the photodynamic properties of photosensitizers based on tetrapyrrole dyes.
Targeted delivery of photosensitizers is one of the main problems of the photodynamic therapy of cancer. Nanodiamonds hold much promise as a delivery platform because of their good sorption ...properties, functionally modifiable surfaces, and low biological toxicity of carbon. In this work, we present a rational design of nanodiamonds for targeted delivery of boronated derivative of e6 chloride to human A431 epidermoid carcinoma cells. Formation of hybrid complexes in aqueous solution is accompanied by deactivation of the excited states of the dye. This prevents generation of reactive oxygen species until the complex reaches the target. In the presence of lipid membranes, the photosensitizers leave the complex and exhibit their photodynamic activity. Modification of the nanodiamond surface by transferrin leads to an additional increase in the efficiency of photodynamic inactivation of cancer cells.
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•Nanodiamond (ND) and photosensitizer BACE form a complex in aqueous solution.•Complex formation prevents photobleaching of BACE.•In the presence of lipid membranes BACE leaves the complex and generates ROS.•Modification of the ND with transferrin enhance photodynamic effect on A431 cells.
Enhancement of optical properties of photosensitizers by additional light-harvesting antennas is promising for the improvement of the photodynamic therapy. However, large number of parameters ...determine interactions of nanoparticles and photosensitizers in complex and, thus the photodynamic efficacy of the hybrid structure. In order to achieve high efficiency of energetic coupling and photodynamic activity of such complexes it is important to know the location of the photosensitizer molecule on the nanoparticle, because it affects the spectral properties of the photosensitizer and the stability of the hybrid complex in vitro/in vivo. In this work complexes of polycationic aluminum phthalocyanines and CdSe/ZnS quantum dots were obtained. We used quantum dots which outer shell consists of polymer with carboxyl groups and provides water solubility and the negative charge of the nanoparticle. We found that phthalocyanine molecules could penetrate deeply into the polymer shell of quantum dot, leading thereby to significant changes in the spectral and photodynamic properties of phthalocyanines. We also showed that noncovalent interactions between phthalocyanine and quantum dot provide possibility for a release of the phthalocyanine from the hybrid complex and its binding to both Gram-positive and Gram-negative bacterial cells. Also, detailed characterization of the nanoparticle core and shell sizes was carried out.
•Binding to QDs affects spectral and photodynamic characteristics of Pcs•Upon binding Pcs can penetrate deeply into the polymer shell of QD•Pcs could be released from the hybrid complex due to interaction with bacterial cell
To study the significance of the rs1378942 polymorphisms of the CSK gene and rs2200733 (chromosome 4q25) in the progression of AF in men with AH and AO.
In an observational cohort study, 116 men aged ...4565 years were followed. Of these, 57 patients with AF, AH and AO and a control group including 59 patients with AF, AH and without AO. Testing of polymorphism rs1378942 of the CSK gene and rs2200733 of chromosome 4q25 using polymerase chain reaction with restriction fragment length polymorphism. All statistical calculations were performed using the Rstudio program (version 0.99.879 20092016 RStudio, Inc., USA).
The average age of all studied patients was 53.37.1 years. When dividing patients with AF and AH into groups based on the presence/absence of AO, it turned out that in the subgroups of carriers of different genotypes of the rs1378942 polymorphism of the CSK gene there are significant differences in BMI: in the group with BMI, there is an increase in the indicator in the series of CC, AC, AA genotypes. The highest BMI value in carriers of the CC genotype (p0.03) was in the group with AO. In the subgroups of carriers of different rs2200733 genotypes of chromosome 4q25, CC has the highest BMI (p0.05). It was proved that in the group with AO, the progression of AF occurred 2.57 times more often than in the group without AO (p0.003).
In men with AF and AH, single nucleotide polymorphisms rs1378942 of the CSK gene and rs2200733 of chromosome 4q25 are associated with BMI. The heterozygous genotype AC rs1378942 in the CSK gene is significantly more common in patients, regardless of the presence of AO. In the group with AO, the progression of AF occurred 2.57 times more often than in the group without AO.
Cytochrome (CYP) 450 isoenzymes are the basic enzymes involved in Phase I biotransformation. The most important role in biotransformation belongs to CYP3A4, CYP2D6, CYP2C9, CYP2C19 and CYP1A2. ...Inhibition and induction of CYP isoenzymes caused by drugs are important and clinically relevant pharmacokinetic mechanisms of drug interaction. Investigation of the activity of CYP isoenzymes by using phenotyping methods (such as the determination of the concentration of specific substrates and metabolites in biological fluids) during drug administration provides the prediction of negative side effects caused by drug interaction. In clinical practice, the process of phenotyping of CYP isoenzymes and some endogenous substrates in the ratio of cortisol to 6β-hydroxycortisol in urine for the evaluation of CYP3A4 activity has been deemed to be a quite promising, safe and minimally invasive method for patients nowadays.
Abstract
The results of raw GNSS data recorded using a Xiaomi Mi 8 android smartphone equipped with a dual-frequency GNSS module BCM47755 capable of receiving and processing signals from the GPS, ...Galileo, QZSS systems in the L1 and L5 frequency sub-bands are presented in the paper. The indices of ionospheric activity that as variations in the relative slant total electron content, the rate of total electron content, the rate of total electron content index, root-mean-square deviation of relative slant total electron content on the base of raw GNSS data are calculated. A comparison study of the data obtained with the data from the KZN2 station of the International GNSS Service network, equipped with a professional GNSS receiver of a geodetic class is carried out. It is shown that the median value of signal strength at frequencies L1 and L5 for the data obtained from the satellites G08, G10, G27, G32, E09 on the Xiaomi Mi 8 smartphone is ≈ 5-25% lower than data from the KZN2 station. The indices of ionospheric activity registered by the Xiaomi Mi 8 smartphone have a higher signal-to-noise ratio in comparison with the data of the KZN2 station. Median levels of variations of the relative slant TEC, ROT, ROTI, and RMSTEC obtained by the Trimble Alloy receiver at KZN2 station were 45÷70% lower than that for the Xiaomi Mi 8 smartphone. Nonetheless, the possibility of registering the indices of ionospheric activity such as relative slant total electron content and others based on dual-frequency raw GNSS measurements (primarily carrier-phase and pseudorange) of GNSS signals received by smartphones opens up prospects for attracting as wide a community as possible for collecting GNSS data and monitoring the ionosphere.
We described a procedure for quick processing images of electrode spots of an oscillatory and unipolar spark discharge onto a flat surface of an iron electrode in an air atmosphere. The images were ...taken using an interference microscope—surface analyzer NewView 5010. The crater diameters were measured using a program for measuring the size of nanopowder particles. A comparative statistical analysis of diameter distributions was carried out using sample comparison tests and analysis of variance included in the Excel package. The factors were the discharge energy and kind of experiment (cathode, anode, oscillatory discharge). It is shown that the characteristics of the distribution of crater diameters weakly depend on the capacitor energy. At the same time, they depend very significantly on the experimental kind. The maximum heights and depths of the relief in the case of an oscillatory discharge are several times higher than their values for a unipolar discharge.
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