The fungicidal activity of some chitosan samples and their nanostructured systems with copper was studied. The samples of Bombyx mori chitosan and its nanostructured systems with copper were found to inhibit growth and development of phytopathogenic fungi Fusarium solani 169 and Verticillium dahlie 57. The growth inhibition zone was of considerable size (22 to 60 mm).

In this review, the research devoted to synthesising chitosan apatites, their biologically active properties, and their application in medical practice is analysed. The data are from articles published between 2001 and 2022 on the formation of calcium- and phosphorus-containing chitosan composites and the mechanism of their interaction.

We obtained binary polyelectrolyte complexes containing chitosan from Bombyx mori and collagen with a mass ratio of 10:1; 10:2, and 10:3. During the interaction between the macromolecules, due to the compensation of the positive charges of chitosan with the negative charges of collagen, the zeta potential of the solutions of polyelectrolyte complexes changed from +15.2 to +5.67 mV. We revealed the dependence of the size characteristics of the particles of polyelectrolyte complexes on time and the ratio of macromolecules. An examination of the morphology of the films of polyelectrolyte complexes demonstrated that in the evaluated chitosan/collagen mass ratios, non-spherical nanosized particles up to ≤ 60 nm form on the surface of the films. We evaluated the mechanism of formation of complexes by using Fourier-transform infrared spectroscopy and confirmed the findings with density functional theory and molecular dynamics. We found that the particle diameter is inversely proportional to the diffusion coefficient. The results show that the particles are almost uniformly distributed over the surface of the polymer matrix and have a unimodal character. We obtained reproducible results when using a chitosan/collagen mass ratio of 10:2 to dye natural silk. We found that the complexes contribute to increase the intensity and stability of colour relative to soap and friction.