New silver-containing hybrid materials based on bacterial cellulose were obtained by a technological approach that combines three techniques: the formation of bacterial cellulose under static conditions, the modification of its surface by plasma treatment, and the introduction of silver nanoparticles obtained by metal vapor synthesis. The plasma treatment is found to significantly change the morphology and composition of the polymer surface. The oxidation state of silver is shown to correspond to Ag0. The resulting systems exhibit antimicrobial activity.

Au, Fe, and AuFe nanoparticles were obtained by metal vapor synthesis using acetone as the dispersion medium. The composition and electronic structure of the particles were studied by TEM, SEM, XPS, XANES, and EXAFS. The Au and Fe particles with average diameters of 5.3 and 1.8 nm, respectively, were obtained. According to X-ray diagnostic methods, gold was in the main Au 0 state, and the Au + and Au 3+ states are present in small amounts while iron existed as mixture of non-stoichiometric oxides with states close to Fe 2+ and Fe 3+ . Bimetallic nanoparticles were solid solutions with a disordered structure and Au–Fe–O and Au–O–Fe bonds. A carbon-containing shell was detected for all types of metal particles. The obtained materials may be promising for the development of improved antimicrobial agents and new methods for treating cancer diseases.

Objective. To determine the minimum inhibitory concentration of Ag nanoparticles in relation to clinical pathogenic strains of microorganisms. Methods. The minimum inhibitory concentration of Ag nanoparticles, obtained by metal vapor synthesis was studied on six strains of pathogenic bacteria, including representatives of gram-positive and gram-negative groups. The microbiological analyzer Vitek 2 Compact was used to identify each strain and to determine the antibiogram. The metal nanoparticles used in the study were synthesized by the method of metalvapor synthesis. Ag nanoparticles were studied by transmission electron microscopy(TEM) and X-ray photoelectron spectroscopy (XPS) methods. Determination of the minimum inhibitory concentration was performed by the method of serial dilution using sterile 96-well plates with using the tests of positive and negative control. The concentration of microorganisms was controlled by the turbidity standard. Results. All pathogenic strains of bacteria used in the study were characterized by pronounced polyantibiotic resistance, and the percentage of antibiotics against which the strain was resistant ranged from 12.5 to 93.3%. The minimum inhibitory concentration of silver nanoparticles ranged from 7.81 to 31.25 μg/ml, depending on the type of microorganism. Gram-positive microorganisms, in contrast to gram-negative ones, were characterized by lower values of the minimum inhibitory concentration. The data of transmission electron and X-ray photoelectron spectroscopy showed that the size of the studied nanoparticles is in the range of 2-15 nm. Conclusion. Silver nanoparticles (2-15 nm in size) have antimicrobial action against clinically significant, polyantibiotic-resistant strains of microorganisms. The minimum inhibitory concentration of silver nanoparticles, depending on the strain of the microorganism, varies from 7.81 to 31.25 μg/ml. Silver nanoparticles have an inhibitory impact on microorganisms and to a greater extent inhibit the growth of gram-positive versus gram-negative. The obtained materials based on silver nanoparticles represent an effective alternative to the currently used antibacterial drugs. What this paper adds The quantitative indices of the antibacterial action of silver nanoparticles have been firstly studied on pathogenic polyantibioticresistant strains of microorganisms The impact of the antibacterial resistance of bacteria does not affect the degree of antimicrobial action of these nanoparticles has been demonstrated Determination of the minimum inhibitory concentration of silver nanoparticles is considered to be a significant step in the development of a scientifically based method of using this class of substances in surgery

In the present work, a promising method was proposed for the formation of new functional nanocomposite materials based on bacterial cellulose and Au nanoparticles obtained by a biocompatible and environmentally friendly metal vapor synthesis. The structure and composition of the composite films surface were studied by XPS, SEM, and IR spectroscopy. It was determined that Au nanoparticles effectively chemisorb the bacterial cellulose nanofibrils forming nanoparticles with a size of about 25 nm with a metal core-hydrocarbon shell structure.