One-Pot Synthesis of Colloidal Hybrid Au (Ag)/ZnO Nanostructures with the Participation of Maleic Acid Copolymers.

One-pot synthesis of colloidal Au/ZnO and Ag/ZnO nanohybrid structures was carried out. The copolymers of maleic acid-poly(N-vinyl-2-pyrrolidone-alt-maleic acid), poly(ethylene-alt-maleic acid), or poly(styrene-alt-maleic acid) were used as templates for the sorption of cations of metals-precursors and stabilization of the resulting nanoheterostructures. Simultaneous production of two types of nanoparticles has been implemented under mild conditions in an aqueous alkaline medium and without additional reagents. Equimolar ratios of the metal cations and appropriate load on all copolymers were used: molar ratio of maleic acid monomeric units of copolymer/gold (silver)cations/zinc cations was 1/0.15/0.23 (1/0.3/0.15). The process of obtaining the heterostructures was studied using UV-Vis spectroscopy. The kinetics of the formation of heterostructures was influenced by the nature of the maleic acid copolymer and noble metal cations used. A high reaction rate was observed in the case of using zinc and gold cations-precursors and a copolymer of maleic acid with N-vinylpyrrolidone as a stabilizer of nanoparticles. The structure of the synthesized polymer-stabilized heterostructures was studied using instrumental methods of analysis-XPS, FTIR, PXRD, and TEM. Under the conditions used, stable colloidal solutions of heterodimers were obtained, and such structure can be converted to a solid state and back without loss of properties.

Synthesis of magnetic chitin-adsorbent for specific proteins.

A simple, convenient and inexpensive method for the preparation of magnetic chitin composite, in which magnetite particles are densely covered with the polysaccharide shell has been developed. Two-step procedure for magnetic chitin preparation includes: (i) adsorption of chitosan onto magnetite particles and (ii) N-selective acetylation of chitosan to produce magnetic chitin. The composite combines the magnetic properties of magnetite and the adsorption properties of chitin. The synthesized magnetic chitin is an efficient adsorbent of ß-d-GlcNAc-specific lectins and lysozyme. The adsorption capacity of magnetic chitin for wheat germ (Triticum vulgaris) and potato (Solanum tuberosum) lectins was in the range of 67-86 mg g-1 of the adsorbent. Magnetic chitin showed the high capacity for enzyme-lysozyme. Synthesized adsorbent is environmentally friendly and recyclable. Magnetic chitin may be used as a promising multi-purpose adsorbent of pollutants of organic or inorganic nature.

Polyelectrolyte thromboresistant affinity coatings for modification of devices contacting blood.

The modification of hydrophobic polyethylene/polystyrene surfaces of medical devices with bilayer/multilayer coatings (BCs/MCs) based on polyelectrolyte complexes (PEC) of modified poly(N-vinylpyrrolidone-co-maleic acid) copolymer (VPMA) with chitosan, amphiphilic chitosan, or albumin was studied. The VPMA contained l-Lysine as affinity ligand for plasminogen attached through alpha-amino group. The surface properties and chemical composition of the surfaces investigated were analyzed, using sessile-drop water contact angle measurements, attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). The specific adsorption of plasminogen (precursor of fibrinolytic enzyme plasmin) from its solutions and from human blood plasma on the modified surfaces was investigated. It was established that polyelectrolyte MCs are more efficient than single-layer BCs and the affine polymer coatings without interlayer. A thrombogenicity decrease for the materials modified with BCs and MCs was shown in in vitro and ex vivo trials.