This article presents the results of the 10-fold cyclic freezing (−37.0 °C) and thawing (0.0 °C) effect on the number and size range of silver nanoparticles (AgNPs). AgNPs were obtained by the cavitation-diffusion photochemical reduction method and their sorption on the fiber surface of various suture materials, perlon, silk, and catgut, was studied. The distribution of nanoparticles of different diameters before and after the application of the cyclic freezing/thawing processes for each type of fibers studied was determined using electron microscopy. In general, the present study demonstrates the effectiveness of using the technique of 10-fold cyclic freezing. It is applicable to increase the absolute amount of AgNPs on the surface of the suture material with a simultaneous decrease in the size dispersion. It was also found that the application of the developed technique leads to the overwhelming predominance of nanoparticles with 1 to 15 nm diameter on all the investigated fibers. In addition, it was shown that after the application of the freeze/thaw method, the antibacterial activity of silk and catgut suture materials with AgNPs was significantly higher than before their treatment by cyclic freezing.

Synthesis and properties of new luminescent amphiphilic Tb(III) complexes [TbL₃·2H₂O]·3H₂O, TbL₃·bipy, [H₃O][TbL₄]·6H₂O and [H₃O][TbL′₃L]·H₂O, where HL is 1-phenyl-3-methyl-4-stearoylpyrazolone-5 and HL′ is 1-phenyl-3-methyl-4-formylpyrazolone-5, are reported. The complexes have been characterized by elemental and thermal analysis, FTIR and luminescence spectroscopy methods. Formation and properties of Langmuir–Blodgett films of the complexes are described. Graphical Abstract

The results of our study of the size, optical properties, and aggregate stability of silver nanoparticles in aqueous solutions 1, 2, and 12 months after their synthesis are reported. It has been shown that nanoparticles synthesized using a combined application of physical factors, such as ultraviolet radiation, ultrasound, and uniform mixing (providing conditions of isolation from the atmospheric air) are smaller in size (from 1 to 10 nm) and have more homogenous distribution of the diameter of nanoparticles. A lower aggregation has been noted compared with particles prepared without observing the synthesis algorithm that was developed and conditions given above. The results of studying antimicrobial antiseptic properties based on a colloidal nanosilver solution prepared using the technology of diffusion-cavitation photochemical reduction of silver nitrate are also reported. A high antimicrobial activity of the resulting colloidal solution with silver nanoparticles against clinical isolates of P. aeruginosa, A. baumanii, and E. coli has been demonstrated as compared with the original silver nitrate and the ligand (polyvinylpyrrolidone) used in the synthesis of the colloid at the same concentration. At a concentration of 10 μg/mL, a colloidal solution with silver nanoparticles has been found to possess bactericidal activity against two isolates of P. aeruginosa, three isolates of A. baumanii, and five isolates of E. coli. At a concentration of 1 μg/mL, the colloidal solution of silver nanoparticles has possessed only bacteriostatic activity against all isolates of the bacteria. The minimum bacteriostatic inhibitory concentration of nanosilver has determined to be 3 μg/mL.

—The study evaluated the adsorption of Ag-containing solutions and gel compositions on modern natural and artificial fibers, as well as polyfilament threads with different coatings. It was...