The search for materials for a new generation of wound coatings is important due to the increase in antibiotic-resistant microorganisms and the number of patients with untreatable chronic purulent wounds. Metal nanoparticles, specifically silver nanoparticles, have antimicrobial activity and do not induce known bacterial resistance. To obtain new Ag-containing nanocomposites, type I collagen was extracted by an enzyme–acid method from cattle tendons. Silver nanoparticles were obtained by an environmentally safe method, metal-vapor synthesis (MVS), which enables obtaining metal nanoparticles without impurities. For this, metal vapors were cocondensed in a vacuum of 10⁻² Pa on the walls of a quartz reactor cooled to 77 K using acetone as an organic dispersion medium. The composition of the collagen surface was determined by XPS using the spectra of C1s, N1s, and O1s. The presence of a peak with a binding energy of approximately 368.57 eV in the Ag 3d_5/2 spectrum indicates the state of Ag⁰ silver atoms in the nanocomposite. SEM images showed that collagen contributes to the effective stabilization of Ag nanoparticles with an average size of 13.0 ± 3.5 nm. It was found that collagen is non-toxic and biocompatible with skin cells and fibroblasts. The collagen–Ag nanoparticle nanocomposites exhibited antimicrobial activity against bacteria Bacillus subtilis, Escherichia coli, and fungi Aspergillus niger.

New hybrid materials based on Ag nanoparticles stabilized by a polyaminopropylalkoxysiloxane hyperbranched polymer matrix were prepared. The Ag nanoparticles were synthesized in 2-propanol by metal vapor synthesis (MVS) and incorporated into the polymer matrix using metal-containing organosol. MVS is based on the interaction of extremely reactive atomic metals formed by evaporation in high vacuum (10⁻⁴–10⁻⁵ Torr) with organic substances during their co-condensation on the cooled walls of a reaction vessel. Polyaminopropylsiloxanes with hyperbranched molecular architectures were obtained in the process of heterofunctional polycondensation of the corresponding AB₂-type monosodiumoxoorganodialkoxysilanes derived from the commercially available aminopropyltrialkoxysilanes. The nanocomposites were characterized using transmission (TEM) and scanning (SEM) electron microscopy, X-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (PXRD) and Fourier-transform infrared spectroscopy (FTIR). TEM images show that Ag nanoparticles stabilized in the polymer matrix have an average size of 5.3 nm. In the Ag-containing composite, the metal nanoparticles have a “core-shell” structure, in which the “core” and “shell” represent the M⁰ and M^δ+ states, respectively. Nanocomposites based on silver nanoparticles stabilized with amine-containing polyorganosiloxane polymers showed antimicrobial activity against Bacillus subtilis and Escherichia coli.

Sustained interest in the use of renewable resources for the production of medical materials has stimulated research on bacterial cellulose (BC) and nanocomposites based on it. New Ag-containing nanocomposites were obtained by modifying various forms of BC with Ag nanoparticles prepared by metal–vapor synthesis (MVS). Bacterial cellulose was obtained in the form of films (BCF) and spherical BC beads (SBCB) by the Gluconacetobacter hansenii GH-1/2008 strain under static and dynamic conditions. The Ag nanoparticles synthesized in 2-propanol were incorporated into the polymer matrix using metal-containing organosol. MVS is based on the interaction of extremely reactive atomic metals formed by evaporation in vacuum at a pressure of 10⁻² Pa with organic substances during their co-condensation on the cooled walls of a reaction vessel. The composition, structure, and electronic state of the metal in the materials were characterized by transmission and scanning electron microscopy (TEM, SEM), powder X-ray diffraction (XRD), small-angle X-ray scattering (SAXS) and X-ray photoelectron spectroscopy (XPS). Since antimicrobial activity is largely determined by the surface composition, much attention was paid to studying its properties by XPS, a surface-sensitive method, at a sampling depth about 10 nm. C 1s and O 1s spectra were analyzed self-consistently. XPS C 1s spectra of the original and Ag-containing celluloses showed an increase in the intensity of the C-C/C-H groups in the latter, which are associated with carbon shell surrounding metal in Ag nanoparticles (Ag NPs). The size effect observed in Ag 3d spectra evidenced on a large proportion of silver nanoparticles with a size of less than 3 nm in the near-surface region. Ag NPs in the BC films and spherical beads were mainly in the zerovalent state. BC-based nanocomposites with Ag nanoparticles exhibited antimicrobial activity against Bacillus subtilis, Staphylococcus aureus, Escherichia coli bacteria and Candida albicans and Aspergillus niger fungi. It was found that AgNPs/SBCB nanocomposites are more active than Ag NPs/BCF samples, especially against Candida albicans and Aspergillus niger fungi. These results increase the possibility of their medical application.

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