[Replication-competent γ-retrovirus Mo-MuLV expressing green fluorescent protein gene as an efficient tool for screening of inhibitors of retroviruses that use heparan sulfate as the primary cell receptor].

The effect of sulfated polysaccharides on the efficiency of infection of mouse embryonic fibroblast cell lines SC-1 and NIH-3T3 by replication-competent recombinant Moloney murine leukemia virus (Mo-MuLV) carrying the eGFP gene was investigated. It was shown that used polysaccharides have no cytostatic and cytotoxic effects on SC-1 and NIH 3T3 cells inthe concentrations from 0.01 to 100 µg/ml and have virucidal activity against Mo-MuLV. Polysaccharides in the indicated concentrations inhibit cell infection by Mo-MuLV, that prevents further expansion of viral infection. It was detected that sulfated polysaccharides are effective inhibitors of other retroviruses, including lentiviruses, that use heparan sulfate as cell receptors for non-specific binding.

[Effect of polysaccharides on biological activity of human lactoferrin].

The influence of neutral and ionic polysaccharides on the antioxidant (AOA) and detoxifying activities of lactoferrin (LF) and the duration of its circulation in the body was studied. In addition to natural polymers, we studied artificial chitosan derivatives with different functional groups. On the basis ofAOA test, five polysaccharides were selected. The study of the detoxifying effect of LF in two models of induced toxicity revealed polysaccharides that maintained or increased the detoxifying activity of LF. We established that the formation of a complex of lactoferrin with two galactomannans and succinyl chitosan caused positive changes in LF properties: the detoxifying activity of the protein remained unchanged or increased, whereas its elimination from the body was decelerated.

[Wound healing potential of chitosan and its N-sulfosuccinoyl derivatives].

Comparative study of chitosan wound healing properties and its synthesized derivatives in MC-100 gel was carried out using the model of experimental full thickness skin wounds. It was determined that N-sulfosuccinoyl chitosan derivatives added into the gel in a concentration of 0.05% possess the higher wound healing activity in comparison with other chitosan derivatives and decrease the half-healing period of wounds 2-3 times in comparison with the control.

[Immunomodulating activity of chitosan derivatives with salicylic acid and its fragments].

A study of biological activity of the derivatives of the chitin-chitosan oligomer with salicylic acid and its fragments showed that chitosan salicylate actively protected potato tubers against Phytophthora infestans but sharply inhibited reparation of potato tissues. N-(2-Hydroxybenzyl)chitosan exhibited good protective properties but did not influence wound reparation. N-(2-Hydroxy-3-methoxybenzyl)-N-pyridox-chitosan, which contained the pyridoxal and 2-hydroxy-3-methoxy fragments, was the most efficient, stimulating both defense against late blight and wound reparation in potato tissues.

[The use of enzymatic preparation for the production of low molecular-weight chitosan from the king crab hepatopancrease].

This article describes the optimal conditions for the enzymatic hydrolysis of chitosan and its chemically-modified derivatives using the preparation extracted from the king crab hepatopancrease possessing pronounced hydrolythic activity. The following preparations were used: chitosan with a molecular weight of 100 kDa and an acetylation level of 0.15, carboxymethyl chitosan 200 kDa witih an extent of replacement of 0.23, and N-succinyl chitosan 390 kDa with an extent of replacement of 0.8. Low molecular-weight samples of chitosan and of its modified derivatives were obtained with the yields of 85, 55, and 80%, respectively. The conditions of the hydrolysis were as follows: an enzyme: substrate ratio of 1:200, 37 degrees C, and 20 h duration of hydrolysis.

Mucoadjuvant properties of lipo- and glycoconjugated derivatives of oligochitosans.

Chitosan, (1-4)-2-amino-2-deoxy-beta-d-glucan, is a deacetylated form of chitin, an abundant biodegradable, positively charged natural polysaccharide. Chitosan is used for antigen delivery through mucosal barrier due to its ability to disrupt tight junctions. Here we produced new water-soluble low-molecular weight chitosan (LMW-Chi) lipid derivatives and compared their ability to stimulate humoral response with the effect of unmodified LMW-Chi or its oligosaccharide derivatives. LMW-Chi effectively penetrated into macrophage-like, lymphoid and epithelial cells. It also stimulated in mice IgG production to model proteins delivered either by subcutaneous or intranasal routes. Adjuvant effect of chitosan derivatives was comparable to or lower than that of unmodified LMW-Chi. Thus, it is possible that adjuvant effect is induced by unmodified glucosamine units of chitosan.