Optimization of physicochemical conditions to produce silver nanoparticles and estimation of the biological effects of colloids synthesized

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.