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N-vinylpyrrolidone-co-allylamine copolymers (VP-co-AA) containing iminodiacetic (IDA) chelation units were prepared in the range of molecular masses of the copolymers from 9000 to 30,000 Da depending on polymerization conditions. Non-radioactive organometallic species Re(CO)3+ were introduced into polymeric carriers under mild conditions, the prepared metal–polymeric complexes were characterized by IR, NMR, ESI-MS and HPLC. IR spectra data confirmed the coordination of M(CO)3+ moiety to the polymeric backbone via IDA chelation unit (appearance of characteristic fac-M(CO)3+ vibrations (2005, 1890 cm−1), as well as the appearance of group of signals in 1H NMR spectra, corresponding to those inequivalent to methylene protons CH2COO (dd, 4.2 ppm), coordinated to metal ions. The optimal conditions for labeling the PVP-co-AA-IDA copolymers with radioactive 99mTc(CO)3+ species were determined. The radiochemical yields reached 97%. The obtained radiolabeled polymers were stable in blood serum for 3 h. In vivo distribution experiments in intact animals showed the high primary accumulation of technetium-99m MPC (MM = 15,000 Da) in blood with subsequent excretion via the urinary tract.

Creation of multifunctional nanoplatforms is one of the new approaches to complex treatment and diagnosis with the monitoring of the curative process. Inclusion of various components into the drug delivery system may reduce toxicity and enhance or modify the therapeutic effects of medicines. In particular, some properties of metal nanoparticles and nanoclusters provide the ability to create new systems for treatment and diagnosis of diseases, biocatalysis and imaging of objects. For example, the ability of metal nanoparticles to enhance the quantum yield of luminescence can be used in bioimaging and therapy. The aim of the research was to construct and examine a multicomponent system based on DNA-polycation compact structure with the inclusion of silver nanoparticles and luminescent dye as a model system for delivery of genes and drugs with the possibility of modification and enhancement of their action.

Copolymers of 2-deoxy-2-methacrylamido- d -glucose with N,N-dimethyl aminoethyl methacrylate were synthesized. Triple copolymers containing N,N-dimethyl-N-dodecyl-N-methacryloyl oxyethyl ammonium iodide units were obtained by alkylation of tertiary amino groups. These copolymers were studied by hydrodynamic and optical methods in various solvents. It was revealed that polyelectrolyte effect in salt-free aqueous solutions is far less pronounced than that in dimethyl sulfoxide (DMSO) solutions. The values of equilibrium rigidity A of alkylated macromolecules in salt-free solutions obtained from viscosimetry data is equal to ∼ (150 ± 50) A in aqueous solutions and to (750 ± 250) A in DMSO solutions. Change in intrinsic anisotropy of alkylated macromolecules in DMSO solutions demonstrated that in the concentration range from 2.5 to 0.5 g/dL, electrostatic interactions lead to isotropic increase in dimensions of macromolecular coils. In the concentration range from 0.5 to 0.02 g/dL, increase in equilibrium rigidity by almost a factor of 4 is observed. It was established that in water-salt solutions of copolymers which contain more than 10 mol.% of dodecyl groups, compact structure is formed; in this structure, intramolecular fragments of polymer chain are hindered. In dimethylsulfoxide solution, in the presence of a salt, the value of intrinsic viscosity [η] increases by more than a factor of 6–8 as compared to that in water-salt solutions. The observed differences in conformation, optical and relaxation properties of the triple copolymers in aqueous and DMSO solutions are related to hydrophobic interactions between alkyl substituents. These interactions lead to the formation of hydrophobic “core” and shielding the charged quaternary ammonium groups ( N + ) in aqua solutions.

Исходя из того, что аграрное образование уже сегодня является ключевым фактором роста устойчивости агросектора России, и основываясь на анализе проблем российского аграрного образования, в статье делается вывод о необходимости ориентации российского аграрного образования на будущее в рамках перспективной национальной деловой культуры.

International audience; The four first generations of dendrigraft poly-L-lysine have been studied in dimethylformamide (aprotic solvent) and in 0.2 M NaCl aqueous solutions by isothermal translation diffusion, 1H NMR and viscometry methods. The relationships between diffusion coefficient, intrinsic viscosity and molar mass have been determined for dendrigraft poly-L-lysines, and the scaling index values have been compared to classical trifunctional dendrimers. Dendrimers and dendrigraft poly-L-lysines exhibited similitudes in their hydrodynamic behaviors. Nevertheless, dendrigraft poly-L-lysines displayed a specific behavior in solution. In contrast to dendrimers, a significant change of hydrodynamic dimension of dendrigraft poly-L-lysines according to the nature of the solvent has been observed. In aprotic solvent, the dendrigraft poly-L-lysine dimensions are about two times lower than in aqueous media (i.e., the hydrodynamic volume is contracted by a factor 8 in dimethylformamide), revealing the softness of dendrigraft poly-L-lysine compared to classical trifunctional dendrimers.

The purpose of the study was to investigate the influence of cationic polymer structure on the formation of DNA-polycation complexes and their transfection activity. Primary, tertiary, and quaternary polyamines with molecular masses ranging from 8000 to 200,000 were investigated. DNA-cationic polymer interaction was characterized by low gradient viscometry, dynamic light scattering, circular dichroism, UV spectrometry, flow birefringence, DNA electrophoresis, and electron microscopy. Transfection activity of the complexes was evaluated by the expression of reporter gene (beta-galactosidase) and using synthetic FITC-labelled oligonucleotides. Complex formation was found to be dependent on the structure and molecular weight of the polymer and the ionic strength of the solution. Secondary DNA structure in complexes was not disrupted, and DNA was protected from protonation. Cell lines of different origin were used for testing of transfection activity of the complexes. The sensitivity of the cells to transfection was established to be highly dependent on the cell line. DNA-polycation complexes are non-toxic according to MTT. Polyallylamine, and polydimethylaminoethylmethacrylate were found to be the most promising polycations for gene delivery. Transfection efficacy of their complexes with DNA to T-98G cells reaches up to 90-100%. It was found that optimal molecular mass of polydimethylaminoethylmethacrylate is in the range of 8000-50,000 Da.

Dispersed Ag nanoparticles were prepared in aqueous solutions in the presence of pure poly[2-(dimethylamino)ethyl methacrylate] (poly-DMAEMA), poly[2-deoxy-2-methacrylamido-d-glucose] (poly-MAG), and their copolymers of poly[MAG–DMAEMA] with different mole fractions. Polymers contributed to the silver reduction, formation of nanoparticles, and stabilization of suspensions. No agglomerations of nanoparticles are formed. For each sample, more than one thousand silver particles were measured by transmission and scanning transmission electron microscopy to determine their number vs diameter and volume versus diameter distributions. The samples with the smallest nanoparticle mode diameter of 2.3 nm were formed in DMAEMA homopolymer suspension, while the mode diameter increased up to 13.3 nm in copolymers depending on the mole fraction of DMAEMA. A model of Ag nanoparticles’ growth taking into account the structure of the copolymers and the amount of reducing centers per monomer is proposed. The volume fraction of large Ag particles (>15–20 nm) in the tail of distributions was determined to estimate the part of less efficient nanoparticles assuming that only surface atoms are active. The largest volume occupied by big particles is measured in the solution with pure poly-MAG. Figures of merit, as the ratio of particle area to total volume of particles, were compared for five systems of Ag NPs/polymer. They can be understood from an economical point of view as the total silver investment compared to efficiency.

The copolymerizations of N-vinylpyrrolidone with N-hydroxyphthalimide and N-hydroxysuccinimide esters of acrylic, methacrylic and crotonic acids have been investigated. The reactivity ratios were determined, and kinetic investigations of the copolymerizations were carried out. It was shown that, by varying the acid component of the monomeric ester, it is possible to obtain reactive copolymers greatly differing in structure.