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Background: One of the future applications of magnetic nanoparticles is the development of new iron-oxide-based magnetic resonance imaging (MRI) negative contrast agents, which are intended to improve the results of diagnostics and complement existing Gd-based contrast media.Results: Iron oxide nanoparticles designed for use as MRI contrast media are precisely examined by a variety of methods: powder X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman spectroscopy, Mössbauer spectroscopy and zero-field nuclear magnetic resonance (ZF-NMR) spectroscopy. TEM and XRD measurements reveal a spherical shape of the nanoparticles with an average diameter of 5–8 nm and a cubic spinel-type crystal structure of space group Fd−3m. Raman, Mössbauer and NMR spectroscopy clearly indicate the presence of the maghemite γ-Fe2O3 phase. Moreover, a difference in the magnetic behavior of uncoated and human serum albumin coated iron oxide nanoparticles was observed by Mössbauer spectroscopy.Conclusion: This difference in magnetic behavior is explained by the influence of biofunctionalization on the magnetic and electronic properties of the iron oxide nanoparticles. The ZF-NMR spectra analysis allowed us to determine the relative amount of iron located in the core and the surface layer of the nanoparticles. The obtained results are important for understanding the structural and magnetic properties of iron oxide nanoparticles used as T2 contrast agents for MRI.

Conjugates for targeted delivery that are based on low-molecular-mass prostate specific membrane antigen (PSMA) inhibitors are widely used and developed because of the deficiencies of existing methods for treating and diagnosing prostate cancer. The major classes of low-molecular-mass PSMA inhibitors, drug classes, and their mechanisms of action are discussed. Therapeutic conjugates for targeted delivery that are based on them are analyzed. Structural features of the linker that affect the biological activity and selectivity are identified.

High-throughput screening identified a new class of antibacterial compounds based on N-pyridyl-substituted p- and m-carboxypiperidine amides. Constructs with the two reporter genes RFP and Katushka2S allowed the detection of compounds that inhibit protein translation against DNA biosynthesis. Some agents of this class demonstrated antibacterial activity by inhibiting translation. The most promising compound had an MIC of 12 μg/mL. Thus, this class could become a valuable platform for developing new compounds with higher antibacterial activity and selectivity.

The scientific and technical literature addressing the synthesis of anisotropic iron-oxide nanoparticles of various shapes (cubic, rod-like, clustered, etc.) sized from 10 to 100 nm and their application for diagnostic magnetic resonance imaging (MRI) of tissues and organs is analyzed. The analysis indicates that the nanoparticle shape, size, and surface chemistry affect considerably relaxation parameters T1 and T2. Thus, cubic iron-oxide nanoparticles had the greatest T2 values. Furthermore, rod-like and octapodal nanoparticles also exhibit rather high T2 values so that they can be used as contrast agents for diagnostic MRI.

A new chiral sorbent based on mercaptosilica modified by gold nanoparticles, then treated by 3-mercaptopropionic acid and macrocyclic antibiotic vancomycin, was obtained. The enantioseparation of isomeric β-blockers (nadolol, atenolol, metoprolol, alprenolol, oxprenolol, and pindolol) by HPLC was studied on the synthesized sorbent. The effect of the composition of the mobile phase (nature and concentration of the organic solvent, concentration and pH of the buffer solution) on retention times of β-blocker enantiomers, selectivity of separation, and resolution of chromatographic peaks were studied. The best separation was achieved for pindolol and metoprolol. The procedure was used to determine the pindolol enantiomers in the preparation “Visken,” and metoprolol in the “Vazocardin” preparation.

Magnetic resonance imaging (MRI) is one of the most perspective methods of noninvasive visualization in medicine, and use of contrast agents significantly its potentialities extends. Iron oxide nanoparticles are promising contrast agents, but in fact all the data on their efficiency were obtained in high-field tomographs for experimental animals. We studied the possibility of using magnetic nanoparticles for MRI visualization of rat brain glioblastoma at the most common clinical field 1.5 T The data indicate the efficiency of iron oxide magnetic nanoparticles as contrast agents for 1.5 T MR tomographs.

New stationary phases for HPLC are obtained via layer-by-layer deposition of polyelectrolytes and studied: (1) silica gel modified layer-by-layer with 6,10-ionene and dextran sulfate (Sorbent 1); (2) silica gel twice subjected to the above modification (Sorbent 2); and (3) silica gel modified with 6,10-ionene, gold nanoparticles, and dextran sulfate (Sorbent 3). The effect the content of the organic solvent in the mobile phase and the concentration and pH of the buffer solution have on the chromatographic behavior of several pharmacologically active nitrogen-containing compounds is studied. The sorbents are stable during the process and allow the effective separation of beta-blockers, calcium channel blockers, alpha-agonists, and antihistamines. A mixture of caffeine, nadolol, tetrahydrozoline, pindolol, orphenadrine, doxylamine, carbinoxamine, and chlorphenamine is separated in 6.5 min on the silica gel modified with 6,10-ionene, gold nanoparticles, and dextran sulfate.

We synthesized a fluorescence conjugate and modified magnetite-gold nanoparticles carrying prostate specific membrane antigen (PSMA) as the ligand. Analysis of their binding to human prostate cancer cell lines PC-3 (PSMA-) and LNCaP (PSMA+) showed selective interaction of the synthesized conjugate and modified nanoparticles with LNCaP cells. These findings suggest that these nanoparticles can be used in tissue-specific magnetic-resonance imaging.

In this work we present the results of the synthesis of magnetite–gold nanoparticles with a core–shell structure. The preparation is carried out in several stages: synthesis of the core, coating with a gold shell, purification of magnetite–gold particles from an uncoated magnetite, and functionalization of the surface with sulfur-containing ligands. The conditions needed for the functionalization of nanoparticles with lipoic acid and mercapto-methoxy polyethylene glycol are indicated in detail, making it possible to determine the optimal conditions needed to achieve an efficient purification and a maximum concentration of the particles in a solution required for biological tests. The possibility of remotely controlling the chymotrypsin properties using an alternating magnetic field has been demonstrated by the example of magnetite–gold nanoparticles. The magnetite–gold nanoparticles which we have obtained are promising for future biomedical applications.

A structured description is suggested for the existing types of copper-containing sites in copper proteins. The most important specific features of mono-, di-, tri-, and tetranuclear sites are reported, and the structural geometry of each site is considered. The functional features and catalytic reactions characteristics of each type of site are discussed. Examples of copper-containing enzyme mimics are considered, and the importance of their synthesis and use is demonstrated.

Herein we report on the synthesis, optimization of the synthetic procedure, functionalization, and characterization of cubic and spherical superparamagnetic magnetite nanoparticles. Spherical nanoparticles (16 ± 2 nm) were synthesized using oleylamine and oleic acid, and cubic (20 ± 2, 5 ± 0.5 nm) nanoparticles were synthesized with oleic acid and small amounts of oleylamine. Covalent modification of the nanoparticles was carried out using heterobifunctional PEG with aminopropyltriethoxysilane and N-hydroxysuccinimide ester moieties. This modification makes both water emulsion stability and further modification of the nanoparticles with cytotoxic drugs possible.

We demonstrated the possibility of penetration of magnetite-gold nanoparticles conjugated with prostate-specific membrane antigen into mouse macrophages. It was found that after 3-h incubation with nanoparticles in a concentration of 15 mg/liter at 37oC, they were seen in only 13% macrophages. In about 90% cells, the nanoparticles were detected within the cytoplasm. Under these conditions, membrane damage was revealed in 25% cells. These results should be taken into account in further development and application of nanomaterials for diagnostic and therapeutic purposes in oncology.

Reflux of imidazole-2-carboxaldehyde, 1-methylimidazole-2-carboxaldehyde, imidazole4-carboxaldehyde, or 5-bromopyridine-2-carboxaldehyde with 2-aminothiophenol in ethanol in the presence of air oxygen for 1.5 h affords the corresponding 2-hetaryl-substituted 1,3-benzothiazoles. The reaction of 2-(1-methyl-1H-imidazol-2-yl)-1,3-benzothiazole with Cu(ClO4)2•6H2O gives bis[2-(1-methyl-1H-imidazol-2-yl)-1,3-benzothiazole]copper(ii) diperchlorate monohydrate.

New sorbents based on silica gel and gold nanoparticles stabilized by L-cysteine and its methyl ester are synthesized. Regularities of the retention of various substituted aminopyridines by the synthesized sorbents are examined in the normal-phase mode of high-performance liquid chromatography upon elution by a binary mobile phase (hexane-isopropanol). Quantum-chemical simulations of L-cysteine and its derivative adsorptions on the surface of a gold cluster are performed, along with simulations of subsequent adsorptions of substituted pyridines on the modified gold surface. It is shown that the Snyder-Soczewinski and Scott-Kucera displacement models can be used to describe the experimental data on the synthesized sorbents.

A reaction of potassium ({(4Z)-4-[(1-methyl-1H-imidazol-2-yl)methylene]-5-oxo-1-phenyl-4,5-dihydro-1H-imidazol-2-yl}thio)acetate with copper(II) chloride in methanol leads to bis(5-anilino-7-methoxycarbonyl-1-methyl-1H-imidazo[1,2-c]pyrimidin-4-ium) tetrachloro-cuprate(II), whose structure was confirmed by the X-ray diffraction studies.

A contact angle test was applied to determine of energy characteristics of the surfaces of polyolefin ketones at various interfacial boundaries and the work of adhesion of polyolefin ketones was calculated in relation to model liquids of various polarities. A new approach was proposed to optimize the selection of polymers for composite materials. It was demonstrated that the contact angle test is a promising express method of forecasting possible branches of applications for polymer materials.

The energy characteristics of surfaces of new polymers belonging to the class of poly(olefin ketone)s at the interfaces with air and polar (water) and nonpolar (octane) liquids were determined by the ?ontact angle method. The objects of the study were binary copolymer (propyl-ene—carbon monoxide, PCO) and ternary copolymers (propylene—carbon monoxide—ethyl-ene—carbon monoxide, PECO; but-1-ene—carbon monoxide—ethylene—carbon monoxide, BECO). It was shown that the ternary copolymers can be recommended for further medicobio-logical tests as a base for the development of hemocompatible materials. The equilibrium values of the interfacial energy of poly(olefin ketone)s at the interfaces with water and octane make it possible to predict their adhesion properties for designing composite materials.

A method for the synthesis of new tetradentate organic ligand of the N2S2 type, viz., N,N’-bis-(2-mercaptophenyl)propane-1,3-diamine has been developed, starting from 2-( tert-butyl-thio)aniline and malonyl dichloride. Coordination compound of this ligand with NiII according to the X-ray diffraction data has a square-planar geometry of the metal ion coordination sphere.

Using the method of cyclic voltammetry the possibility of formation of the Pd(II) complex with triarylphosphine ligand on the gold electrode surface is shown resulting from the following sequence of reactions: (1) formation of the self-organized monolayer (SOM) of di(11-mercaptoundecyl)disulfide on the Au surface; (2) esterification of terminal hydroxy groups of the formed SOM with diphenyl(p-carboxyphenyl) phosphine; (3) formation of the complex compound fixed on the surface by treatment of the modified electrode with solution of PdCl2 in CH3CN. The possibility of electrocatalytic reduction of iodobenzene on the gold electrode with participation of the obtained Pd(II) complex is demonstrated.

Gold nanoparticles that have an average size of 2.2 nm and are modified bo bis[13-(pyridine-4-yl)tridecyl]disulfide have been synthesized, and their aggregation upon interaction with Cu(ClO4) · 6H2O and Co(ClO4) · 6H2O has been investigated. new method to obtain gold nanoparticle ensembles of different shapes and aggregations continues on the basis of the coordination interaction of ligands adsorbed on the surface of gold nanoparticles with a transition metal ions.

Cu(ClO4)2·6H2O was shown to react with 2,2′-[propane-1,3-diylbis(thio-2-phenylnemethylidene]-bis(3-pyridylamine) (I) or (5Z)-2-ethoxycarbonylmethyl-(2-pyridylmethylidene)-3,5-dihydro-4H-imidazol-4-one (II) in the presence of CH3CN with the reduction of copper(II) to copper(I) and the formation of the tetrahedral complex CuI(CH3CN)4ClO4 (III). In the course of the reaction the organic ligands I and II were oxidized to the corresponding sulfoxides.

Self-organized monolayers (SOMs) of 2-thiohydantoins on gold modified with lipoic acid esters were studied using contact angle measurements. The feasibility of complexing SOMs with cobalt(II) ions was demonstrated. Optimal parameters were determined for generating surface metal complexes on gold.

A series of the M(L)Cl2 · nH2O and {M(L)}2(OAc)4 complexes (M = NiII, CoII, and CuII; L is 3- and 4-(2-pyridyl)-1,3-benzothiazole) were synthesized by the reaction of L with MX2 · nH2O (X = Cl, OAc) in ethanol. The molecular and crystal structures of the CuL2(OAc)4 binuclear complex (L is 4-(2-pyridyl)benzothiazole) were determined by X-ray diffraction analysis. The copper atoms have a distorted tetragonal bipyramidal environment and are coordinated to the nitrogen atom of the pyridine moiety of the ligand and to two oxygen atoms of the bridging acetate ligands. The Cu-Cu distance is 2.6129(9) A. The electrochemical behavior of the synthesized ligands and complexes was studied using the cyclic voltammetry and rotating disk electrode techniques in DMF solutions (0.1 M Bu4NClO4). The primary reduction of all the complexes under study is directed to the metal.

A facile and convenient method is offered for the synthesis of composite material consisting of 1,4-bis(terpyridine-4′-yl)benzene microcrystals and gold nanoparticles with an average size of ∼15 nm adsorbed on their surfaces. The nanohybrid material is obtained by the deposition of presynthesized nanoparticles on the surface of the organic compound.

Metallography, DTA, x-ray, and electron-probe microanalysis methods have been applied to alloys with four compositions in the cast and annealed states. A phase diagram has been constructed for the entire concentration range on the basis of these data together with published ones. The diagram is of peritectic type, and the peritectic temperature is 1500°C. The mutual solubilities of the components at that temperature are 13.3 at.% osmium in nickel and 13 at. % nickel in osmium. The solubility of osmium in nickel falls to 9.2 at. % when the temperature is reduced to 1200°C.