Sarkyt E. Kudaibergenov

Controllable stability of DNA‐containing polyelectrolyte complexes in water–salt solutions

Destruction of polyelectrolyte complexes (PECs) formed by DNA and synthetic polyamines of different structures was carried out by addition of low molecular weight electrolyte to PEC solution at different pHs. The dissociation was studied by the fluorescence quenching technique using the ability of cationic dye ethidium bromide to intercalate into free sites of DNA double helix followed by ignition of ethidium fluorescence. Structure of amine groups of the polycation was shown to be a decisive factor of PEC stability. PECs formed by polycations with quaternary amine groups, i.e., poly(N-alkyl-4-vinylpyridinium) bromides, poly(N, N-dimethyldiallylammonium) chloride, and ionene bromide, were pH independent and the least tolerant to destruction by the added salt. Primary amine groups of basic polypeptides poly-L-lysine hydrobromide and poly-L-arginine hydrochloride as well as synthetic polycation poly(vinyl-2-aminoethyl ether) provided the best stability of PECs in water-salt solutions under wide pH range. Moderate and pH-dependent stability was revealed for PECs included poly(N,N-dimethylaminoethylmethacrylate) with tertiary amine groups in the chain or branched poly(ethylenimine) with primary, secondary, and tertiary amine groups in the molecule. The data obtained appear to be the basis for design of DNA-containing PECs with given and controllable stability. The design may be accomplished not only by proper choice of polyamine of one or another type, but by using of tailor-made polycations with given composition of amine groups of different structure in the chain as well. Thus, quaternization of a part of tertiary amine groups of poly(N, N-dimethylaminoethylmethacrylate) resulted in expected decrease of stability of DNA-containing PECs in water-salt solutions. The destruction of PEC formed by random copolymer of 4-vinylpyridine and N-ethyl-4-vinylpyridinium bromide was pH sensitive and could be performed under pH and ionic strength closed to the physiological conditions. This result appears to be particularly promising for addressing DNA packed in PEC species to the target cell.

Complexation of amphoteric copolymer of 2-methyl-5-vinylpyridine-acrylic acid with copper(II) ions and catalase-like activity of polyampholyte-metal complexes

Abstract The interaction of polyampholyte based on 2-methyl-5-vinylpyridine and acrylic acid with copper(II) ions in aqueous solution has been investigated. Several types of complexes were formed, dependent on pH. The catalytic action of polyampholyte-copper(II) complex in hydrogen peroxide decomposition has been studied. The kinetic parameters and activation energy of this process were determined. The relation between the structure of complexes and their catalytic activity is also discussed.

Properties of polyelectrolyte complex membranes based on some weak polyelectrolytes

Membranes derived from the polyelectrolyte complexes of polyvinyl ether of monoethanol amine and poly-N-methyl-4-vinylethynyl piperidinol-4 with polyacrylic acid and copolymers of acrylic acid and vinylbutyl ether have been prepared and their swelling properties were studied as a function of copolymer composition, solvent composition, pH, ionic strength and temperature. The permeability of polyelectrolyte complex membranes with respect to urea has been also considered.

Interaction of synthetic polyampholytes with anionic and cationic detergents in aqueous solution

SummaryThe interaction of amphoteric macromolecules with ionic surfactants is accompanied by a strong decrease of the dimensions of the polyelectrolyte chains, but the complex particles are retained from precipitation by the presence of the hydrophylic components of the polyampholyte. The behaviour of the complex polyampholyte-detergent depends both on the nature of amphoteric copolymers and on the ionic detergents.

Interpolymer complexes of some vinyl copolymers in a solution and on the boundary of two liquid phases

Abstract By electrochemical and spectroscopic methods the interaction of acrylic acid and vinylbutyl ether, acrylic acid and styrene, vinyl ether of monoethanol amine and styrene copolymers with some anionic (polyacrylic and polymethacrylic acids) and cationic (polyvinyl ether of monoethanol amine and poly-N-methyl-4-vinylethynyl piperidole-4) polymers have been investigated in a solution and on the boundary of two non-mixing liquids. The formation of interpolymer complexes with exact composition occurs. Upon realization of complexation on the liquid–liquid boundary the complex formation reaction has some time, caused obviously by diffusion of interacting macromolecules to the interface layer where the interaction takes place.

Interaction of richlocain with some linear and crosslinked polymers

Abstract The interaction of local anesthetic drug richlocain with linear polyacrylic acid and crosslinked sodium polyacrylate, linear and crosslinked acrylic acid–Schiff base copolymers has been investigated. The compositions of forming polymer–drug complexes were determined. The influence of external factors such as pH, ionic strength, temperature and thermodynamic quality of solvent on the stability of these complexes was studied. The kinetics and activation energy of drug release from the gel matrix has been evaluated.

Layer-by-Layer Thin Films and Coatings Containing Metal Nanoparticles in Catalysis

The layer-by-layer (LbL) technique is one of the most promising ways of fabricating multilayer thin films and coatings with precisely controlled composition, thickness, and architecture on a nanometer scale. This chapter considers the multilayer thin films and coatings containing metal nanoparticles. The main attention was paid to LbL films containing metal nanoparticles assembled by convenient methods based on the different intermolecular interactions, such as hydrogen bonding, charge transfer interaction, molecular recognition, coordination interactions, as driving force for the multilayer buildup. Much attention has paid to the LbL films containing metal nanocomposites for multifunctional catalytic applications, in particular, photocatalysis, thermal catalysis, and electrocatalysis. The preparation protocol of LbL-assembled multilayer thin films containing metal nanoparticles (such as Au, Ag, Pd, Pt), metal oxides (Fe 3 O 4 ), and sulfides (CdS) that are supported on the various surfaces of nanotubes of TiO 2 , Al 2 O 3 membranes, graphene nanosheets, graphene oxide and further applications as catalysts with respect to photocatalytic, electrocatalytic performances is discussed. The systematization and analysis of literature data on synthesis, characterization, and application of multilayer thin films and coatings containing metal nanoparticles on the diverse supports may open new directions and perspectives in this unique and exciting subject.

Bovine Serum Albumine Complexation with Some Polyampholytes

Purified protein preparations, which recently were used only in biochemical laboratories, nowadays are coming more and more into our everyday life as medicine preparations and detergents. They are used in fine organic synthesis and food production as well as in a variety of analytical techniques. One of the effective methods of protein separation and purification is protein precipitation (liquid phase splitting) with the help of polyelectrolytes. The most extensively studied protein complexes are mixtures of lysozyme1, albumins2-4, gelatin5,6, and catalase7,8 with weak and strong polyelectrolytes of linear and crosslinked structure.

DESIGN, STRUCTURE, AND BEHAVIOR OF INTERPOLYMER COMPLEX MEMBRANES

Polyelectrolyte complex (PEC) formation reactions between oppositely charged linear polyelectrolytes have been considered in detail.1-4 PEC formation reactions represent an interesting principle to develop PEC films,5 membranes,6 and microcapsules7,8 with unique permselective characteristics towards liquids,9 gases,10 and ions.11 Usually, at a low concentration of mixing polyelectrolytes PECs precipitate and the processing of thin films or membranes becomes a multistage process that includes the following steps: 1) the separation of precipitate; 2) dissolution of precipitate in a ternary mixture consisting of water, organic solvents, and neutral salts; 3) casting; 4) removal of impurities. Whereas a thin interfacial film of PEC about 20 nm thick is rapidly formed at higher polyelectrolyte concentrations (above 0.6 wt.%, or about 0.03 N).11 This film is stoichiometric and because of its impermeability the reaction is stopped after the initial formation of the thin film.