Application of bacterial cultures to cationic coatings leads to cell dysfunction and death. A traditional "biocidal paradigm" considers cell death resulting from their direct contact with the outer surface of the coating, which carries toxic cationic groups. To clarify the mechanism of antimicrobial polymer action, model anionic polymer microspheres, fixed K562 cells, and Gram-negative bacteria and Gram-positive bacteria have been deposited over the coatings from synthetic cationic poly(diallyldimethylammonium chloride). The cells come from the environment in small water-salt droplets, which adsorb on the coating and induce a set of processes, including (1) dissolution of the polycation and its binding to the cells, (2) migration of the polycation between individual cells in solution, (3) adsorption of polycation-cell complex onto the coating, and (4) transfer of the polycation from the coating to the cell surface. Taking together, these processes ensure high efficacy of the biocidal action of cationic polymer coatings. The fact that cells are washed off the coatings being bound to cationic polymer should be taken into account when designing antimicrobial experiments and interpreting results.

The possibility of using carboxymethylcellulose as a platform for transporting ruthenium or bismuth ions in the body along with a medicinal preparation (a thiourea-derived NO synthase activator) was examined. Carboxymethylcellulose microgels were obtained by cross-linking with ruthenium or bismuth ions in a biological environment, and differences in their physicochemical parameters were identified. Furthermore, it was found that the size and aggregation stability of the microgels depend on the amount of the introduced organic ligand-drug.

Application of bacterial cultures to cationic coatings leads to cell dysfunction and death. A traditional "biocidal paradigm" considers cell death resulting from their direct contact with the outer surface of the coating, which carries toxic cationic groups. To clarify the mechanism of antimicrobial polymer action, model anionic polymer microspheres, fixed K562 cells, and Gram-negative bacteria Pseudomonas aeruginosa and Gram-positive bacteria Staphylococcus aureus have been deposited over the coatings from synthetic cationic poly(diallyldimethylammonium chloride). The cells come from the environment in small water-salt droplets, which adsorb on the coating and induce a set of processes, including (1) dissolution of the polycation and its binding to the cells, (2) migration of the polycation between individual cells in solution, (3) adsorption of polycation-cell complex onto the coating, and (4) transfer of the polycation from the coating to the cell surface. Taking together, these processes ensure high efficacy of the biocidal action of cationic polymer coatings. The fact that cells are washed off the coatings being bound to cationic polymer should be taken into account when designing antimicrobial experiments and interpreting results.

Two series of novel 4-nitro-5-styrylisoxazoles (11 compounds) containing various macrocyclic substituents at positions 3 and 5 of the isoxazole cycle were obtained. Isoxazoles with macrocyclic signal unit in the styryl moiety demonstrated sensor properties in organic solvents to a number of metal cations (Mg(II), Ca(II), Zn(II), La(III), Al(III), Pb(II)). Aggregation-induced emission for the obtained dyes was found in the mixture of DMSO/H2O. In the presence of serum albumin, aggregates of macrocyclic styrylisoxazoles in an aqueous medium dissociated into monomers and formed complex with macromolecule. The compounds demonstrated cytoplasmic distribution in cells in two different forms as aggregates with ‘red’ fluorescence and dyes complexes with cellular proteins with ‘green’ fluorescence, which is promising for studying metabolic processes in the cell.

The hybrid hydrogels were synthesized composed of hyaluronate/polyacrylate mixture cross-linked by magnetic gamma-Fe2O3 nanoparticles. Incorporation of short polyacrylate chains into the hydrogels increases the size of gamma-Fe2O3 nanoparticles thus enhancing the magnetic hydrogel properties. The hydrolytic enzyme initiates degradation of the hybrid hydrogels down to smaller particles, which persist in solution due to complexation with polyacrylate chains. The results are of interest for preparing magnetically controlled biodegradable polymer carriers for encapsulation of bioactive substances.

In this work, double conjugate-microgels of Bi-CMC with different content of bismuth natural isotope were obtained and physicochemically characterized. The aggregative stability was demonstrated and the hydrodynamic and electrokinetic characteristics of Bi-CMC microgels under physiological conditions were quantitatively studied. The cytotoxicity of the obtained microgels was studied with respect to both tumor and healthy cells. The approach used to prepare microgels with stable bismuth ions was applied to obtain microgels cross-linked with radionuclide 207Bi with following parameters of decay: T1/2= 31.55 years, EC 99.962 %, beta+ 0.038 %. The obtained microgels labeled by 207Bi[Bi]3+ ions allowed a comparative analysis of the accumulation and organ distribution of radioactive ions within the microgel and free 207Bi3+ ions using a mouse model.

Eight different types of tea bags were investigated in this work using dynamic light scattering, electrophoretic mobility and nanoparticle tracking analysis methods to determine the concentration and size of released particles from the bag materials at different temperatures and times. Infrared spectroscopy and calorimetric methods confirmed that the bag material consisted of synthetic (nylon or polypropylene) or natural polymers (cellulose). The size of the released particles lies in the range of 200 nm–1 µm with an initial bimodal distribution and with an average diameter of about 600 nm. The concentration of released particles increases with increasing temperature and brewing time. The released particles of synthetic polymers remain quite stable and are not affected by natural enzymes, while cellulose particles are easily degraded by the proteolytic complex Morikrase. When analyzing the electrophoretic mobility, it was found that the released particles have a negative surface charge, which probably determines the absence of cytotoxicity established on the epithelial cell line Caco-2 even at the maximum values of the observed particle concentrations (14 × 109 particle/L for synthetic polymers and 170 × 109 particle/L for cellulose).

A method for synthesizing magnetic polymer microspheres with carboxyl groups on the surface is proposed. In an aqueous medium, magnetic microspheres form stable colloidal dispersions with an average hydrodynamic particle diameter of 110–170 nm and a negative surface charge. When dispersed in an aqueous–organic mixture, the microspheres remain resistant to aggregation. Microspheres can be extracted from the dispersion using an external magnetic field. Magnetic microspheres can be used as supports for heterogeneous catalysts operating in organic media.

In the article, new colloidal systems are obtained and studied, which have prospects for use as carriers of medicinal compounds. The colloidal systems under consideration are polymer complexes based on polyacrylic acid of various molecular weights and biogenic polyamine with magnetic iron oxide nanoparticles. The magnetic properties of polycomplexes with included magnetic iron oxide nanoparticles have been studied.

Synthetic and natural polymers are widely used for constructing drug delivery systems. Biocompatibility, water solubility and non-toxicity make polymers a convenient matrix for encapsulation, delivery and release of bioactive compounds. Coupling of a drug with a biodegraded polymer matrix is a promising way for a controlled drug delivery. Along this line, the degradation of the four polymers in the presence of two enzymes in aqueous solutions was investigated. The following polymers were used: natural polysaccharides, sodium alginate and sodium hyaluronate, artificial (modified) sodium carboxymethylcellulose and synthetic sodium polyacrylate (control); their degradation was caused by the addition of alginate lyase and hyaluronidase. The first enzyme only cleaved the specific alginate substrate and left three other intact. Contrastingly, the second enzyme degraded all three polysaccharides, including artificial carboxymethylcellulose, but did not degrade synthetic polyacrylate. The biodegradation of polymers was accompanied by decreasing the size of polymer particles in solution from 100 to 200 nm down to 20-30 nm; the latter are capable of removing from the body through the kidneys. The initial polysaccharides showed the negative surface charge in aqueous solution, which changed but retained negative after biodegradation. The initial and biodegraded polysaccharides demonstrated negligible cytotoxicity during long exposure period. The obtained results are valuable for the development of polymer carriers for drug encapsulation and delivery.

In this study, we provide the first experimental evidence that colloidal hydrophilic magnetite nanoparticles can penetrate through bilayer lipid membrane in a non-uniform stationary magnetic field. Hydrophilic ligand-free cationic colloidal magnetite nanoparticles with an average diameter of 4 nm were added to the surrounding aqueous solution on one side of the azolectin membrane. An external non-uniform magnetic field ensured the attraction of superparamagnetic magnetite nanoparticles to the membrane, resulting in the formation of a near-membrane charged layer of cationic nanoparticles resulting in the initial polarization of the membrane. As a result of the passage of magnetite nanoparticles through the membrane, the polarization of the membrane decreases, and the membrane becomes depolarized. Independent methods were used to detect magnetite nanoparticles that passed through the lipid membrane including transmission electron microscopy and energy-dispersive x-ray spectroscopy. The discovered effect may be due to the following factors and interactions of nanoparticles. Interaction of magnetic nanoparticles with external inhomogeneous magnetic field provides localization of nanoparticles on the membrane surface. Collective interactions between nanoparticles, as well as their interactions with external electric and magnetic fields, lead to the formation of magnetite nanoparticle aggregates. Interaction of nanoparticles with the membrane lipid matrix leads to the formation of organic-inorganic complexes in which the polar surface of nanoparticles is enveloped by a lipid layer. The penetration of nanoparticles through the membrane is caused by the interaction of organic-inorganic complexes of nanoparticles and their aggregates with local intramembrane and near-membrane electric and magnetic fields.

An elegant method of one-pot reaction at room temperature for the synthesis of nanocomposites consisting of cerium containing nanoparticles stabilized by carboxymethyl cellulose (CMC) macromolecules was introduced. The characterization of the nanocomposites was carried out with a combination of microscopy, XRD, and IR spectroscopy analysis. The type of crystal structure of inorganic nanoparticles corresponding to CeO2 was determined and the mechanism of nanoparticle formation was suggested. It was demonstrated that the size and shape of the nanoparticles in the resulting nanocomposites does not depend on the ratio of the initial reagents. Spherical particles with a mean diameter 2–3 nm of were obtained in different reaction mixtures with a mass fraction of cerium from 6.4 to 14.1%. The scheme of the dual stabilization of CeO2 nanoparticles with carboxylate and hydroxyl groups of CMC was proposed. These findings demonstrate that the suggested easily reproducible technique is promising for the large-scale development of nanoceria-containing materials.

Micro-sized hydrogels synthesized by electrostatic cross-linking of anionic alginate with Ca2+ cations were additionally loaded with cationic fluorescent dye Rhodamine 6B or cationic antitumor antibiotic doxorubicin. Forming complexes with Ca2+ alginate hydrogels, doxorubicin retained or even reduced its toxicity to tumor and normal cells. The results can be used to design containers for the encapsulation and delivery of drugs and control their interaction with cells.

The controllable delivery of drugs is a key task of pharmacology. For this purpose, a series of polymer composites was synthesized via the cross-linking of hyaluronate and a hyaluronate/polyacrylate mixture with Fe2O3 nanoparticles. The cross-linking imparts magnetic properties to the composites, which are more pronounced for the ternary hyaluronate/polyacrylate/γ-Fe2O3 composites compared with the binary hyaluronate/Fe2O3 composites. When dispersed in water, the composites produce microsized hydrogel particles. Circulation of the ternary microgels in an aqueous solution at a speed of 1.84 cm/s can be stopped using a permanent external magnet with a magnetic flux density of 400 T. The composite hydrogels can absorb the antitumor antibiotic doxorubicin (Dox); the resulting constructs show their cytotoxicity to tumor cells to be comparable to the cytotoxicity of Dox itself. The addition of the hyaluronidase enzyme induces degradation of the binary and ternary microgels down to smaller particles. This study presents prospectives for the preparation of magnetically controlled biodegradable polymer carriers for the encapsulation of bioactive substances.

Tubulin-targeting agents attract undiminished attention as promising compounds for the design of anti-cancer drugs. Verubulin is a potent tubulin polymerization inhibitor, binding to colchicine-binding sites. In the present work, a series of verubulin analogues containing a cyclohexane or cycloheptane ring 1,2-annulated with pyrimidine moiety and various substituents in positions 2 and 4 of pyrimidine were obtained and their cytotoxicity towards cancer and non-cancerous cell lines was estimated. The investigated compounds revealed activity against various cancer cell lines with IC50 down to 1–4 nM. According to fluorescent microscopy data, compounds that showed cytotoxicity in the MTT test disrupt the normal cytoskeleton of the cell in a pattern similar to that for combretastatin A-4. The hit compound (N-(4-methoxyphenyl)-N,2-dimethyl-5,6,7,8-tetrahydroquinazolin-4-amine) was encapsulated in biocompatible nanocontainers based on Ca2+ or Mg2+ cross-linked alginate and it was demonstrated that its cytotoxic activity was preserved after encapsulation.

The ability of gold polyacrylate (aurumacryl) to increase the sensitivity of murine tumor (В-16/F10 melanoma) to radiation treatment has been explored. Radiation therapy employed in combination with aurumacryl leads to a moderate but significant inhibition of tumor growth by 81–90

Water-dispersible complexes of 4-methyl-N-[5-methyl-3-(3,4,5-trimethoxyphenyl)isoxazol-4-yl]benzamide possessing anticancer activity were prepared by its immobilization with biocompatible polymer nanocontainers based on sodium alginate cross-linked with Ca2+ and Mg2+ ions. It was found that this isoxazole derivative retains its structure during immobilization. Colloidal stable nanocontainers filled with this compound exhibit toxicity toward the colon carcinoma (HCT116) tumor cell line.

Synthesis of polymer nanocomposite as nanocontainers for doxorubicin (DOX) is carried out at a molar ratio of monomer units of the anionic polysaccharide (sodium hyaluronate) and Ca2+-ions as a cross-linking agent equaled to 10/1. Highly water-soluble white fibrous products can be prepared. The hydrodynamic diameter of nanocompsite (Ca2+/Na-Hyaluronate) particles is equal to 150 nm. At the same time, diameter of the original sodium hyaluronate (Na-Hyaluronate) macromolecules is about 300 nm. The interaction between synthesized nanocomposite particles, Ca2+/Na-Hyaluronate, and DOX accompanied by a new complex formation can be confirmed by means of fluorimetry. Obtained results indicate that the nanocomposite is capable as an immobilizing doxorubicin nanocontainer.

Chloro-substituted lutetium(III) phthalocyanines were obtained using fast and effective (yields 75-78%) template synthesis under microwave irradiation. Target compounds possess intense (log epsilon similar to 5) absorption in the range 680-700 nm, which overlaps with the "therapeutic window" range for photosensitizers in photodynamic therapy. Chloro-substituted complexes demonstrate moderate quantum yields (up to 54% for perchlorinated complex) of singlet oxygen generation. Moreover, chloro-substituted lutetium(III) phthalocyanines showed the ability to generate the superoxide anion radical (O-2(-center dot)) with higher efficiency compared to unsubstituted analog. Stable colloid suspensions of the water-soluble nanoparticles were obtained by incorporation of the chlorinated lutetium(III) phthalocyanines into mixed polylactide micelles. The dark and photoinduced cytotoxic activity of the obtained nanoparticles was tested using the HeLa cell line. Demonstrated results showed a promising potential of the chlorinated lutetium(III) phthalocyanines as photosensitizers for medical applications.

Carboxymethylcellulose (CMC) complexes cross-linked with copper ions exhibit radiation stability, up to high doses of radiation (∼2000 Gy). A model estimate of the exit of copper ions from the CMC—Cu complexes, in which CMC can be a radionuclide ( 67 Cu 2+ ) carrier, showed that the dose load on the body does not increase for the calculated estimate of the real medical dose (∼750 Gy).