| Popis: |
Due to the significant increase in the resistance of microorganisms to the action of medicines, primarily antibiotics, the search for other antibacterial agents, including the preparation of silver-based drugs, is extremely important. In small concentrations (50 mcg/l), silver is safe for a living organism, but shows a destructive effect against most bacteria and viruses. The use of silver in the form of nanoparticles (NPAg) can reduce its concentration by hundreds of times compared to the ionic form, while preserving all its antimicrobial properties. An important task is both the development of non-toxic antimicrobial drugs based on silver NP that retain their bactericidal properties and stability over a long period, and the elucidation of the mechanisms of interaction of NPAg with cells and tissues of a living organism. The aim of this work was to study the effect of specified concentrations of NPAg on the structure (size) of particles and surface tension (ST) of model systems obtained on the basis of crude egg phosphatidylcholine and cholesterol. In the work, mixtures of the following lipids were studied in detail: PCe1 – crude phosphatidylcholine, Chol – cholesterol. It was shown that under the influence of middle concentrations of NPAg (up to 0,3–0,5 rel. units) in samples with PCe1 significant changes in the particle size in the mixture occur. Moreover, in mixtures of Chol with PCe1, the addition of NPAg even at a low concentration (0,01 rel. units) already causes a decrease in the average particle diameter by 1,5 times. It has been shown that the presence of sufficiently large NPAg particles (at surface lifetimes from 0,5 to 5 s) gives higher ST values, and a change in the particle size leads to changes in ST: an increase in size – an increase in ST, a decrease in size – a decrease in ST. The equilibrium ST is apparently influenced by the presence of NPAg particles of different sizes in the sample and their ratio. A study of the interaction of NPAg with natural compounds, such as phospholipids, polysaccharides, proteins and peptides, is of great fundamental and practical importance. |
