Peptide-protein complex from cattle sclera: Structural aspects and chaperone activity.

The influence of temperature and chaotropic agents on the spatial organization of the peptide-protein complex isolated from cattle sclera at the level of secondary structure was studied by UV, CD spectroscopy, and dynamic light scattering. It is shown that this complex has high conformational thermostability. The point of conformational thermal transition (65 °C) was determined, after which the peptide-protein complex passes into a denatured stable state.

Effect of Bioactive Peptide Complex Isolated from Bovine Serum on Proliferation and Migration of Mesenchymal Stromal Cells In Vitro and Reparation of Bone Defects In Vivo.

We studied the effect of a bioactive peptide complex isolated from bovine serum on the proliferative potential and migration rate of mesenchymal stromal cells in vitro, as well as on the healing of modeled bone defects in rats. This bioregulatory preparation stimulated proliferation of mesenchymal stromal cells from deciduous tooth pulp in vitro, but did not affect the rate of their migration in two-dimensional cultures. In vivo experiments showed that application of this preparation in combination with hydroxyapatite and chitosan gel accelerated bone tissue regeneration, thus ensuring restoration of morphologically normal bone matrix.

Induction of Osteogenesis in Rat Bone Tissue Using Cryogenically Structured Porous 3D Materials Containing a Bioregulator.

We studied osteogenesis induction after implantation of porous cryogenically structured 3D scaffolds based on chitosan, alginate, and serum albumin and containing a bioregulator from bovine serum into in vivo modeled experimental bone defect in rats. It was shown that such 3D-matrices are effective as osteoconductors due to their effect on osteoblast precursors. All types of bioregulator-loaded 3D materials promote active bone repair, which manifested in restoration of the dense bone tissue, formation of the bone marrow, and the recovery of osteons on day 14 after surgery.

Extraction of residual heavy metals from commercial chitosan and approach to preparation of oligochitosan hydrochloride.

For biomedical applications, chitosan and oligochitosan must be appropriately characterized and meet pharmacological requirements in terms of contamination by residual heavy metals. In this work, a series of commercial chitosans was analyzed by ICP-MS method, and high concentration of Fe (44-382 ppm), Cr (3.1-35.

Consequences of chitosan decomposition by nitrous acid: Approach to non-branched oligochitosan oxime.

It is well known that chitosan degradation by nitrous acid leads to oligochitosan (oligoCHI-ahm) bearing reactive 2,5-anhydromannose (3,4-dihydroxy-5-hydroxymethyl-tetrahydrofuran-2-aldehyde) units at the new reducing ends of macromolecules. Standard protocol requires reduction of oligoCHI-ahm with NaBH to corresponding oligoCHI-hml bearing unreactive hydroxymethyl group instead of reactive aldehyde group. For the first time, HP SEC as well as UV and CD spectroscopy methods have revealed that the reduction leads to an indefinite side modification and the formation of a branched oligoCHI-hml with increased molecular weight.

Effect of Bioregulators Isolated from Rat Liver and Blood Serum on the State of Murine Liver in Roller Organotypic Culture after CCl4-Induced Fibrosis.

We studied the protective effect of bioregulators isolated from the liver and blood serum of mammals under conditions of manifest fibrosis. Fibrosis was induced by CCl4 administration for 30 days and then, the liver was cultured in a roller organotypic culture for 30 days in the presence of bioregulators. Hepatoprotective effect of bioregulators was evaluated on histological sections of the liver at different terms of culturing.

[Bioregulator from rat liver tissue].

It has been shown that the membranotropic homeostatic tissue-specific bioregulator isolated from rat liver tissue contains a nanosized peptide-protein complex consisting of low-molecular peptides (1–6.5 kDa) and a protein from the serum albumin family. This bioregulator modulated the peptide biological activity and determined the tissue specificity.

[Biologically Active Peptides of King Crab Hepatopancreas].

Substances of a peptide nature isolated from the hepatopancreas of the king crab Paralithodes camtschaticus exhibited physicochemical properties and membranotropic and specific activities similar to those of membranotropic homeostatic tissue-specific bioregulators previously found in different mammalian and plant tissues. Their biological effect on vertebrate tissues was demonstrated on a model of roller organotypic cultivation of Pleurodeles waltl newt liver tissue.

[Biologically Active Peptides Isolated from Dill Anethum graveolens L].

Peptide mixtures with molecular weights of 1000-2000 Da and in vivo membrano-trophic activity against mouse hepatocyte culture at very low concentrations were isolated from dill Anethum graveolens L. leaves. It has been found that plant peptides in aqueous solution formed larger nanosized particles of approximately 90 nm with a secondary structure mainly composed of β-structures and random coil structures.

Analysis of a bioregulator isolated from rat testes in roller organotypic culture of mouse testes in vitro.

A new bioregulator, a representative of membranotropic homeostatic tissue-specific bioregulators acting in ultralow doses, was isolated from rat testes. A model of roller organotypic culturing of mouse testes was developed and the protective effect of the bioregulator was analyzed.

Burn-healing effects of a composition containing chitosan gel and a blood serum bioregulator.

We studied the effect of combined preparation on the basis of chitosan containing a bioregulator isolated from cattle serum in a concentration of 10(-10) mg/ml on healing of II-IIIa degree skin burns in mammals in vivo.

Study of wound-healing activity of bioregulators isolated from eye tissues and bovine serum in the model of experimental corneal injury in rabbits in vivo.

We compared wound-healing activity of bioregulators isolated from cattle cornea, serum, and retinal pigment epithelium on in vivo model of experimental corneal injury in rabbits. Bioregulators were instilled into the eye as solutions at a concentration corresponding to 10(-12) mg protein/ml. The animals were sacrificed on day 21 after injury and the corneas were examined histologically.

Effect of a composition containing chitosan gel and a bioregulator from blood serum on healing of purulent wounds in mice.

We studied the effect of combined preparation on the basis of chitosan containing a bioregulator isolated from cattle serum in a concentration of 10(-10) mg/ml on healing of purulent wounds in mammals in vivo.

Experimental models for culturing of eye tissues of Pleurodeles waltl for evaluation of specific effects of sclera bioregulator in ultra-low doses.

Experiments on stationary culture of posterior eye and roll-bottle culture of the whole eye from adult water lizards Pleurodeles waltl showed that sclera bioregulator produces a stabilizing effects on adhesion interactions between the sclera, choroid, and pigment epithelium and on the maintenance of viability of sclera fibroblasts and pigment epithelium cells.

Effect of bioregulators isolated from the liver, blood serum, and bile of mammals on the state of newt liver tissue in organotypic culture.

We developed models of in vitro organotypic culturing of newt liver tissue with and without adhesion to the substrate. The effects of bioregulators isolated from mammalian liver, blood serum, and bile were studied on the developed models and their specificity was demonstrated. The state of the liver was evaluated by the area of clusters of pigmented cells and by the number of mitoses in the connective tissue cells of the cortical layer.

On mechanisms underlying regeneration and reparation processes in tissues.

Studies of the probability of regulating the regenerative and reparative processes in pathologically modified tissues are reviewed. A ready cell system, providing the realization of reparative and regenerative processes in all organs (cell sources of regeneration), exists in all organisms. The authors suggest that active bioregulators, presented in this paper, are involved in the mechanisms of tissue regeneration by modulating the cell sources of regeneration.

Structural-functional characteristics of a new bioregulator isolated from bovine pigmented epithelium tissue.

A new bioregulator operating in ultralow doses corresponding to 10(-17) mg/ml has been isolated from tissue of pigmented epithelium of bovine eyes. It has been established that the functional basis of this bioregulator is a complex of a low molecular weight regulatory peptide (4372 Da) and a modulator consisting of a mixture of proteins with molecular weights of 14.980-66.

Copolymers of maleic acid and their amphiphilic derivatives as stabilizers of silver nanoparticles.

Silver nanoparticles were prepared by reduction of the corresponding metal salt with NaBH(4) in the presence of appropriate dispersing agents, namely, copolymers of maleic acid: poly(N-vinyl-2-pyrrolidone-alt-maleic acid), poly(ethylene-alt-maleic acid), poly(styrene-alt-maleic acid) or their amphyphilic derivatives. A thorough study of the whole process of silver nanoparticles production including formation of polymeric silver salt and stabilization of nanoparticles has been carried out. The degree of cooperativity of copolymer silver ions binding process and binding capacity of copolymers with respect to silver ions was calculated.

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 mechanism of alpha-proton isotope exchange in amino acids catalysed by tyrosine phenol-lyase. What is the role of quinonoid intermediates?

To shed light on the mechanism of isotopic exchange of alpha-protons in amino acids catalyzed by pyridoxal phosphate (PLP)-dependent enzymes, we studied the kinetics of quinonoid intermediate formation for the reactions of tyrosine phenol-lyase with L-phenylalanine, L-methionine, and their alpha-deuterated analogues in D2O, and we compared the results with the rates of the isotopic exchange under the same conditions. We have found that, in the L-phenylalanine reaction, the internal return of the alpha-proton is operative, and allowing for its effect, the exchange rate is accounted for satisfactorily. Surprisingly, for the reaction with L-methionine, the enzymatic isotope exchange went much faster than might be predicted from the kinetic data for quinonoid intermediate formation.

Use of the affinity chromatography principle in creating new thromboresistant materials.

The principle of affinity chromatography was used for preparation of thromboresistant bilayer coatings. The outer biospecific layer containing epsilon-aminocaproic acid residues (from 2.2 up to 5.