O. A. Pisarev

Molecularly imprinted hydrophilic polymer sorbents for selective sorption of erythromycin

New hydrophilic polymer sorbents comprising reactionary sites which are complementary to a molecule of antibiotic erythromycin were synthesized by the method of molecular imprinting. A series of similar sorbents without reactionary sites was used for comparison of sorption characteristics. Sorption of erythromycin on both types of polymer sorbents synthesized was studied in a wide range of pH and ionic strength. Selectivity of erythromycin sorption on molecularly imprinted cross-linked polymers was shown to depend on the specific interaction of target molecule with polymer matrix. This type of sorbent is perspective for the development of antibiotic purification directly from a culture medium Saccharopolyspora erythreus.

Mass transfer effects in preparative chromatography of eremomycin on polymeric sorbents.

This work is devoted to the study of the regularities of the sorption of the new antibacterial antibiotic eremomycin on carboxylic sorbents. The main sorption kinetic equilibrium and dynamic parameters for realization of one-act preparative chromatographic process were determined and the difference between gel-like and structurally segregated carboxylic cation exchangers was analyzed. The optimal conditions for sorption and complete desorption of eremomycin were found.

Sorption of Lysine by Molecularly Imprinted Carboxyl Sorbents

Tuned (molecularly imprinted) and nontuned, with respect to lysine amino acid, carboxylic heteroreticular sorbents based on methacrylic acid and ethylene glycol dimethacrylate, were synthesized. Study of sorption of lysine within wide pH range and ionic strength indicated significant dissimilarities in amino acid sorption by tuned sorbents, which were expressed as an increase in the contribution of nonionic interaction, and resulted in a decrease in the ionic strength effect on the sorption capacity, as well as an increase in amino acid sorption selectivity.

Optimization of experimental conditions for the preparative displacement chromatography of antitumor anthracycline antibiotics on carboxylic sorbents

The physico-chemical conditions and the limits of the rates of mobile phases are determined when effective regimes of preparative chromatography in the conditions of sharpening the boundaries of chromatographic zones of anthracycline antibiotics are realized. The influence of pH on the equilibrium, kinetics and dynamics of sorption of anthracycline antibiotics (rubomycin, doxorubicin and carminomycin) on the carboxylic sorbents has been studied.

Polymer sorbent with the properties of an artificial cholesterol receptor

A cholesterol-imprinted polymer sorbent and the corresponding reticular control copolymer were synthesized from hydroxyethyl methacrylate and ethyleneglycol dimethacrylate. The sorption isotherms of cholesterol were analyzed using the generalized Langmuir and Freundlich equations. In the case of the imprinted reticular polymer, cholesterol sorption occurred on the energetically homogeneous binding centers, forming one monolayer, while the nonspecific sorption of cholesterol on the control copolymer occurred with energetically nonhomogeneous binding of the sorbate and depended on the physicochemical conditions of sorption.

Synthesis and sorption properties of polymeric sorbents molecularly imprinted with uric acid

Polymeric sorbents molecularly imprinted with a uremic toxin, uric acid, were prepared by suspension copolymerization of 2-hydroxyethyl methacrylate and ethylene glycol dimethacrylate in the presence of uric acid. The physicochemical and sorption properties of the synthesized sorbents and of the corresponding control sorbents synthesized without uric acid were studied. The influence of the amount of the introduced template on the structural features and sorption capacity of the synthesized polymers was determined. As compared to control sorbents, the synthesized imprinted sorbents exhibit increased equilibrium sorption capacity for uric acid.

Molecularly imprinted polymeric sorbents for selective sorption of erythromycin

Two types of polymeric sorbents were synthesized by molecular imprinting from methacrylic acid as functional monomer and ethylene glycol dimethacrylate as cross-linking agent, with erythromycin antibacterial antibiotic used as template. Sorbents of the first type are carboxylic heteronetwork cation exchangers with high capacity for Na+ ions, obtained in the presence of various amounts of the template molecules. Sorbents of the second type are hydrophilic materials prepared under the conditions when methacrylic acid and erythromycin were present in the polymerization mixture in equimolar amounts. A comparative study of the equilibrium and kinetics of erythromycin sorption on the synthesized sorbents showed that the equilibrium sorption capacities of the materials of the second type for the antibiotic exceeded those of the materials of the first type. The molecular imprinting led to the formation of sorption sites homogeneous in the affinity for erythromycin in the polymer network, to an increase in the effective diffusion coefficients, and to a decrease in the mean time of the antibiotic sorption, compared to the control sorbents.

Influence of the molecular weight and structural organization of cationic polyelectrolytes on protein flocculation

A complex on-line procedure based on combined use of integral (spectroturbidimetry) and differential (nephelometry) light scattering methods was applied to studying the size and formation kinetics of dispersed particles in solutions containing a protein and synthetic cationic soluble polymers. The influence of pH of the medium and of the molecular weight and structural organization of polymers on the floccule size and flocculation kinetics was evaluated.

Low-basic anion exchangers based on glycidyl methacrylate for selective sorption of endotoxin

Radical copolymerization of glycidyl methacrylate with vinylpyrrolidone and glycidyl methacrylate with vinylformamide, followed by modification with glucosamine, was used to synthesize low-basic anion exchangers for extracorporeal removal of endotoxins from blood plasma. The effect of the glucosamine concentration on the basicity of the polymeric sorbents was studied and optimal conditions for modification of network polymers were found. Their physicochemical and sorption properties were examined. It was shown that the main contribution to the change in the free energy of sorption of the endotoxin by the synthesized polymeric sorbents is made by hydrophobic interactions, with the increase in the basicity of the anion exchangers leading to a rise in sorption capacities.

Synthesis and properties of polymeric and organo-inorganic amphiphilic sorbents molecularly imprinted with cholesterol

Polymeric and organo-inorganic sorbents molecularly imprinted with cholesterol were synthesized to create selective hemosorbents for efferent therapy of hypercholesterlemia. These sorbents are block copolymers of 2-hydroxyethyl methacrylate and ethylene glycol dimethacrylate and granulated organo-inorganic sorbents in which the imprinting was performed in the layer of the above copolymer on the surface of selenium (Se) nanoparticles stabilized with polyvinyl pyrrolidone. The physicochemical and sorption properties of the sorbents were studied.