Dekina S. Biotechnology of mucoadhesive lysozyme-polymeric systems for medical purpose

The thesis is devoted to the development and application of biotechnological approaches for the immobilization of lysozyme into polymers of synthetic and natural origin, with the aim of creating new mucoadhesive systems of antibacterial action. Using entropy and enthalpy, as well as ionized electronegativity as descriptors, a QSAR model was for the first time obtained, that adequately describes the effect of metal ions on enzyme activity. Approaches have been developed to increase the hydrolytic activity of free and immobilized lysozyme and to expand the spectrum of its antimicrobial action by adding the disodium salt of ethylenediaminetetraacetic acid and proteolytic enzymes. It was shown that stabilization of the enzyme with polymer solutions occurs due to the formation of associates and depends on the nature, structure and concentration of polymer carriers. A lysozyme preparation for tear replacement therapy “artificial tear” was obtained with preservation of hydrolytic activity of 95.5% for 1 year. The stabilization of the enzyme is achieved by the formation of ionic bonds between the hydroxyl groups of dextran and the amino groups of lysozyme, and mucoadhesive properties are provided by the addition of hydroxypropyl methylcellulose. Using the sodium salt of carboxymethyl cellulose as a matrix, immobilization of lysozyme and lysozyme with quercetin was carried out by gel incorporation. T The lysozyme included in the polymer matrix is stable after immobilization and sterilization by γ-radiation (28 kGy). The obtained films are effective in the treatment of experimental stomatitis in rats: a decrease in inflammation and markers of microbial contamination of the mucous membranes by 80.9% and 97.5%, respectively. In all cases, immobilization in polymer matrices positively affects the functioning of lysozyme: it stabilizes the enzyme molecule, contributing to the expansion of pH and thermal profile of activity, long-term storage, provides directed hydrolytic effect on mucous membranes due to mucoadhesive properties of polymers. The usage of modern analytical methods for monitoring the effectiveness of immobilization in work provides important information on the effect of this process on the stability and activity of the enzyme, and makes a significant contribution in the biotechnology of immobilization of lysozyme.