ИСТИНА

New materials based on Au and Ag nanoparticles stabilized in a matrix of microcrystalline and bacterial cellulose were prepared for medical applications. Au and Ag nanoparticles were synthesized in i-PrOH by metal vapor synthesis (MVS) and incorporated into the polysaccharide matrix using metal-containing organosol. The MVS is an efficient route of purposeful synthesis of metallic nanoparticles and their derived composites as well. Microcrystalline cellulose brand Avicel PH-101 with a polymerization degree of 180 and an average particle size of 50 μm was used. Bacterial cellulose films were synthesized by Gluconacetobacter hansenii producer strain. The materials were characterized by transmission and scanning electron microscopy (TEM, SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction, Fourier-transform infrared spectroscopy and thermogravimetric analysis (TGA). TEM shows that Au and Ag particles with average sizes of 10.2 and 17 nm, respectively, are on the surface of microcrystalline cellulose powder. The valence state of Au and Ag is estimated to be Au0 and Ag0 by XPS. In accordance with the TGA data, the introduction of Au and Ag nanoparticles into microcrystalline cellulose has practically no effect on the thermal stability of metal polymers. SEM shows that the bacterial cellulose films containing metal nanoparticles consist of filament fibers of different diameters, of which micro- and macrofibrils with a diameter of 15-20 and 50-100 nm, respectively, were formed. The metal nanoparticles have a wide size distribution. The bacterial cellulose nanocomposite is a gradient material in which the metal concentration decreases from the surface to the middle of the film.