Biomedical subjects

V P Zubov

Publications and source records attributed to V P Zubov.

At least 19 recordsLinked to original sources

PubMed2001

Immobilized thrombin receptor agonist peptide accelerates wound healing in mice.

To accelerate the healing processes in wound repair, attempts have been repeatedly made to use growth factors including thrombin and its peptide fragments. Unfortunately, the employment of thrombin is limited because of its high liability and pro-inflammatory actions at high concentrations. Some cellular effects of thrombin in wound healing are mediated by the activation of protease activated receptor-1 (PAR-1). The thrombin receptor agonist peptide (TRAP:SFLLRN) activates this receptor and mimics the effects of thrombin, but TRAP is a relatively weak agonist. We speculated that the encapsulated peptide may be more effective for PAR-1 activation than nonimmobilized peptide and developed a novel method for TRAP encapsulation in hydrogel films based on natural and synthetic polymers. The effects of an encapsulated TRAP in composite poly(N-vinyl caprolactam)-calcium alginate (PVCL) hydrogel films were investigated in a mouse model of wound healing. On day 7 the wound sizes decreased by about 60% under TRAP-chitosan-containing PVCL films, as compared with control films without TRAP. In the case of TRAP-polylysine-containing films no significant decrease in wound sizes was found. The fibroblast/macrophage ratio increased under TRAP-containing films on day 3 and on day 7. The number of proliferating fibroblasts increased to 150% under TRAP-chitosan films on day 7 as compared with control films. The number of [3H]-thymidine labeled endothelial and epithelial cells in granulation tissues was also enhanced. Thus, the immobilized TRAP to PVCL-chitosan hydrogel films were found to promote wound healing following the stimulation of fibroblast and epithelial cell proliferation and neovascularization. Furthermore, TRAP was shown to inhibit the secretion of the inflammatory mediator PAF from stimulated rat peritoneal mast cells due to augmentation of NO release from the mast cells. The encapsulated TRAP is suggested to accelerate wound healing due to the anti-inflammatory effects and earlier development of the proliferative phase of wound healing.

Adjuvants, Immunologic↗

PubMed2001

A study of moss (Marchantia polymorpha) thylakoid membrane lipids in monolayers.

Monolayers of seven fractions of natural lipids (phosphatidyl inositol, sulfoquinovosyl diacylglycerol, phosphatidylcholine, digalactosyl diacylglycerol, phosphatidyl glycerol, phosphatidylethanolamine, monogalactosyl diacylglycerol), isolated from the photoautotrophic cell culture of the moss Marchantia polymorpha grown under normal and light-stress conditions, have been prepared for the first time. We have shown that the high-intensity light affects the area occupied by the lipid molecule. In the case of digalactosyl diacylglycerol and phosphatidyl glycerol fractions, after the light stress the area significantly increased from 0.50 to 0.80 nm2 and from 0.47 to 0.63 nm2, respectively, and in the case of the sulfoquinovosyl diacylglycerol fraction, the area decreased from 0.40 to 0.32 nm2. These results are in agreement with our previous data on the redistribution of the double bonds in the aliphatic chains of these lipids and can be used to characterize the state of the lipid bilayer of the thylakoid membranes.

Bryopsida↗

PubMed2000

[Turbidimetric study of latex agglutination in 2,4-dichlorophenoxyacetic acid analysis].

By the example of 2,4-dichlorophenoxyacetic acid (2,4-D) assay by the inhibition of latex agglutination, new synthetic polymer microspheres for the conjugation with antibodies to 2,4-D and agglutinators based on ovalbumin and polyacrylamide were developed and characterized. The effect of various parameters (the concentration of reagents, the type and the degree of modification of the microsphere surface, and the nature of the carrier in the composition of the agglutinator) on the rate of agglutination and the maximal optical absorption observed during the reaction were studied by turbidimetry. The optimal parameters were found for the assay of 2,4-D by the inhibition of latex agglutination with turbidimetric registration of the results.

2,4-Dichlorophenoxyacetic Acid↗

PubMed2000

[Synthesis of amphiphilic photochromic benzo-15(18)-crown-5(6)-ethers and their properties in monolayers].

New amphiphilic photochromic benzo-15(18)-crown-5(6) ethers (APC) differing in the position of the octadecyl substituent and the size of the crown cavity were synthesized. The compounds form stable monolayers in the air/water and air/alkaline metal salt solution interfaces. The results of the pressure isotherm measurements, atomic force microscopy (AFM), and electronic spectroscopy show that the structure of the monolayers formed depends on the structure of the parent APC and the nature of the cation in salt solutions. The area per molecule of APC in the monolayer (specific area) is the smallest on the water surface and increases by 20-40% on the aqueous subphase surface with an increasing concentration of salts therein to indicate the formation of APC complexes with the metal cations. When the hydrophobic aliphatic substituent is displaced from position 3 to position 5 of the benzothiazole ring, the specific area on the surface of water and subphases decreases twofold, which indicates the compactization of the monolayer on this modification. A reversible E-Z-photoisomerization of APC was found in the monolayers formed in the salt solution/air interface. The features of the reaction are defined by the specific organization of the amphiphilic molecules in the monolayer and by the nature of the cation.

Air↗

PubMed2000

Cellular localization of the galactose-binding lectin from human serum.

An SL2 lectin was isolated from human serum and characterized previously; cellular localization of the lectin was studied using polyclonal rabbit antibodies. According to cytofluorimetry, anti-SL2 antibodies bound only to lymphocytes and monocytes but not to other blood cells. Antibodies bound to Jurkat T cell lymphoma but did not interact with IM-9 cells of B cell origin. Moreover, the Jurkat cells bound oligosaccharides having the highest affinity to SL2 (GalNAcalpha_and Fucalpha1-2Gal), and this interaction was inhibited by anti-SL2 antibodies. Lysis of the Jurkat cells with subsequent electrophoresis and Western blotting indicates that anti-SL2 antibodies recognized a 14-kD protein.

Animals↗

PubMed2000

Features of the behaviour of double-chained cationic surfactant monomer in a monolayer at the water-gas interface.

We studied the formation of a double-chained cationic monomer, N,N-diallyl-N-cetyl-N-dodecyloxycarbonyl methylammonium bromide, in a monolayer at the water-gas interface. An increase in surface pressure induced the transition from the liquid-expanded to liquid-condensed state with tail-packing and then head-packing of the monomer, which was accompanied by a decrease in the mobility of monomer molecules. An increase in the ionic strength of the subphase led to the compression of the layer, and addition of ethanol or detergents caused its dilution. Polyethylene glycol and polyacrylic acid induced the formation of a complex between the monomer and polymer.

Biophysical Phenomena↗

PubMed1999

[Molecular design of polymeric materials for biotechnology and medicine].

This review describes new polymer materials for biomedical applications developed in the Polymers for Biology Laboratory of the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences. These include composite rigid sorbents for biochromatography, polymer dispersions for immunoassay, polymer hydrogels for immobilization of enzymes and cells, and polymer ultra thin films as biomembrane models and materials for biosensors. Some general and specific properties of these new materials and models as well as examples of their applications are discussed.

Adsorption↗

PubMed1998

Immunoreagents based on polymer dispersions for immunochemical assays.

Immunoreagents based on polymer dispersions consisting of unimodal polyacrolein (PAL) microspheres with diameters in the range 0.3-2.0 microns have been prepared and evaluated by various immunoassay techniques such as immunoradiometric assay of ferritin and microtitre particle agglutination and immunofiltration dot assay of group-specific polysaccharide of S. pyogenes (A-PS) in comparison with conventional carriers and methods. The antibodies were covalently or indirectly bound to the PAL. The coupled antibodies to ferritin retained a high average affinity (Ka = 4.5 x 10(9) M-1). In comparison with microcrystalline cellulose-based immunosorbent, more than an order-of-magnitude lower amount of PAL-IgG was necessary for the analysis of ferritin. Use of PAL-IgG gave a higher sensitivity of assay with a detection limit of 0.7 x 10(-13) M l-1 and a wider concentration range of antigen detection (about four orders of magnitude) without manifestation of the high-dose hook effect. Particle agglutination assay of A-PS in microtitre plate was shown to be a simple, demonstrative and highly sensitive one-step analytical method with a detection limit of 0.05 ng A-PS/ml or 10(4) cells/ml. The sensitivity of immunofiltration assay using both enzyme and latex markers was shown to be approximately the same (50 ng A-PS/ml) and the duration of the assay was 3-5 min. No cross-reaction of latex conjugates with non-A Streptococcus cell lysates were observed.

Acrolein↗

PubMed1998

[Composite fluorine polymer-containing sorbents for isolation and purification of biopolymers].

Composite fluoropolymer-containing sorbents based on porous silicas were synthesized for the isolation and purification of biopolymers under nondenaturing conditions. Examples of the application of these sorbents in the separation of various mixtures of peptides and proteins and purification of nucleic acids from various sources (plasmid DNA and DNA from nucleated human blood cells) using the cartridge, column, and batch (sorption in a stirred volume) methods are presented. It was shown that the sorbents can be used in laboratory practice because they are selective to nucleic acids (DNA and RNA) and proteins. These materials combine the mechanical properties of the inorganic matrix with the specific sorption properties of the polymer phase and exhibit enhanced stability to alkaline hydrolysis. Alternative methods of preparing sorbents containing polytetrafluoroethylene, polytrifluorostyrene, and polyfluorobutadiene are described. By the example of polyfluorobutadiene-containing sorbents, a completely new method for obtaining fluorinated polymer phases was developed: the polymer phase was preliminarily formed on the surface of porous disperse carriers and was fluorinated with xenon difluoride.

Adsorption↗

PubMed1998

[Thrombin--a regulator of reparative processes in wound healing].

Thrombin, binding to receptors of the protease activated receptor (PAR) family, is involved in wound healing by inducing the reparation processes and regulating the activity of mast cells, which secrete mediators of inflammation. Using thrombin receptor agonist peptide (TRAP-6) for the activation of rat mast cells, effect of several receptors, including PAR-1, on mast cells was demonstrated. It was shown that TRAP increases the concentration of Ca2+ in the cytoplasm of mast cells and regulates cell degranulation, while releasing nitrogen oxide. Thrombin encapsulated in poly(N-vinyl caprolactam)-calcium alginate (PVCL-Ca-Alg) hydrogel films promotes wound healing in rats as demonstrated by the acceleration of fibroblast proliferation and neovascularization.

Animals↗

PubMed1998

[Effect of surfactants on peroxidase activity. I. Effect of anionic surfactants].

The effect of various anionic surfactants on the initial rate of 5-aminosalicylic acid peroxidation with horseradish peroxidase was studied. With increasing surfactant concentration, this rate first decreased, then increased, and again decreased. We conclude that these changes were due to an inhibition of the enzyme, a subsequent change in the enzyme conformation accompanied by the enhanced accessibility of its active site to the substrate, and the final protein denaturation, respectively.

Anions↗

PubMed1996

Polymer ultrathin films with immobilized photosynthetic reaction center proteins.

Mixed monolayers of lipids with photosynthetic reaction center proteins (RCs) from Rb. sphaeroides and C. aurantiacus were studied and the optimum conditions for stable films fabrication were determined. The following synthetic: ACPE, TDA, PDA, DODL and natural lipids: PE, PC were used. The rate of polymerization of the mixed ACPE-RC and TDA-RC monolayers is lower than those for pure lipid-like monomers on the air/water interface but high enough for the fast preparation of the polymer films. The optical and photoelectrical measurements provide evidence for an orientation of RCs (from Rb. sphaeroides) on interface. Hydrophilic H-subunit in the mixed ACPE-RCs and DODL-RCs monolayers is preferentially oriented towards water as in the pure RC monolayers. Opposite orientation was found with TDA-RCs and PDA-RCs films. No preferential orientation was found for lipid-RCs (C. aurantiacus) monolayers probably because of the low asymmetry of hydrophobic subunits (M and L) of these RCs.

Chlorobi↗

PubMed1996

[Isolation and characteristics of galactose-binding lectins from human blood serum].

Two galactose-binding lectins, SL1 and SL2, were isolated from human serum by two-step affinity chromatography on sorbents with immobilized disaccharides Gal beta 1-3GlcNAc beta (Lec) and Fuc alpha 1-2Gal beta (Hdi). The purification degree of the SL1 and SL2 preparations was 4000-6000 times and yields were 6.9 and 4.7 micrograms/ml of serum, respectively. Electrophoresis showed that both lectins are oligomers with molecular masses of about 440 kDa, which are composed of ca. 67 kDa subunits. The carbohydrate specificity of the lectins was assayed by hemagglutination inhibition using mono- and oligosaccharides. Both lectins showed specificity for Gal and GalNAc residues but differed in the interactions with oligosaccharides. In particular, SL1 showed maximum affinity for disaccharide Gal beta 1-3GalNAc beta (in the form of 4-nitrophenyl glycoside), 6'-sialyllactose, and disaccharide residues Fuc alpha 1-3Gal beta and Gal alpha 1-3Gal beta, whereas SL2 was specific for GalNAc alpha residue and its derivatives as well as for disaccharide Hdi.

Carbohydrate Sequence↗

PubMed1995

Characterization of weak hydrophobic composite sorbents and their application to the isolation of bacterial lectin.

Composite sorbents based on wide-pore glass and silica coated with N-butyl polyacrylamide (butyl-PA-glass and butyl-PA-silica) were studied. The surface tension of butyl-PA-silica is 50-55 mJ/m2 as evaluated by the sedimentation volume technique. The linear dependences of log k' on ammonium sulphate concentration were determined by isocratic chromatography of the dipetide Trp-Trp and lysozyme on butyl-PA-glass. Both solutes were shown to have a weaker retention on butyl-PA-glass than on butyl-Toyopearl 650C. This weaker retention is beneficial in the purification of sialic acid-binding lectin from Bacillus subtilis.

Acrylic Resins↗

PubMed1995

Purification of monoclonal antibodies to Le(y) and Le(d) carbohydrate antigens by ion-exchange and thiophilic-adsorption chromatography.

The paper deals with convenient and fast methods for purification of monoclonal antibodies (MAbs) to carbohydrate antigens Le(y) and Le(d) from the cell culture and ascite fluid by ion-exchange chromatography on S-Sepharose and salt-promoted chromatography on a "thiophilic" adsorbent. One-step procedure on S-Sepharose of MAbs to Le(y) (IgG and IgM) provides significant purification (over 90% of contaminants were removed), while a purification factor for IgM to Le(d) is much lower. Highly purified IgM to Le(d) could be obtained by a two-step purification procedure including "thiophilic-adsorption" chromatography and gel-filtration (90-98% of contaminants from the cell culture and ascite fluid were removed). The preparations of IgG and IgM retain their initial antibody activity.

Adsorption↗

PubMed1995

[Polyacrolein latex as a solid phase carrier for radioimmunoassay. Comparison with microcrystalline cellulose and polystyrene test tube surface].

The immunosorbent obtained through a covalent immobilization of antibodies on a polyacrolein latex was studied in comparison with the sorbents based on microcrystalline cellulose and with the surface of polystyrene test tubes in a two-center radioimmunoassay for ferritin. It was shown that the polyacrolein latex provides a covalent binding of up to 75 mg protein per g dry polymer with an immobilization efficiency of 50-70% and a high effective association constant of immobilized antibodies (Ka = 4.5 x 10(9) M-1). The same parameters for the sorbent based on microcrystalline cellulose were 33 mg/g, 25-35%, and 4.3 x 10(8) M-1, respectively. In the radioimmunoassay for ferritin, the immunosorbents based on polyacrolein latex and cellulose ensured a nearly the same analytical sensitivity at the level of (0.7-0.9) x 10(-13) M ferritin and pointed to the possibility of eliminating the "hook-effect". Compared to the immunosorbent based on polystyrene test tubes, the advantages of the polyacrolein latex are the decrease in the minimum detectable concentration (increase in analytical sensitivity), the extension of the dynamical range of analysis, and the absence of the "hook-effect".

Acrolein↗

PubMed1994

[Noninstrumental immunoanalysis based on dyed polyacrolein latexes. Determination of a group-specific polysaccharide from Streptococcus pyogenes].

Non-instrumental immunoassays based on immunofiltration and microtiter particle agglutination (MPA) techniques have been developed using coloured polyacrolein latex. These methods have been applied to the quantification of the group-specific polysaccharide (PS) of S. pyogenes (group A streptococcus) and compared with standard ELISA tests. The most efficient method was MPA; as little as 0.05 ng A-PS/ml could be detected in 1.5 h. In comparison with ELISA test, the sensitivity of MPA was 10 times higher and the procedure was much simpler. The sensitivity of immunofiltration assay using both enzyme and latex conjugates was shown to be the same (50 ng/ml A-PS) and the duration of the assay 3-5 min. No cross-reactions of latex conjugates with non A streptococcus cell lysates have been observed. The developed methods are rapid, robust, easy to perform, don't need any sophisticated equipment and specially trained staff.

Acrolein↗

PubMed1994

[A new method of immobilizing proteolytic enzymes in polymeric hydrogels].

A novel one-step method for enzyme immobilization in composite gels based on the thermally reversible polymer poly (N-vinyl-caprolactam) was developed. Conditions for entrapment of trypsin and carboxypeptidase B in the gels were optimized. After immobilization, 80 and 90% of the original carboxypeptidase B and trypsin activities, respectively, were found to retain. Both immobilizes enzymes were active in a wider pH and temperature range. The granules with entrapped enzymes were successfully applied to obtain human insulin from recombinant proinsulin.

Caprolactam↗