Аннотация:The creation of effective antibacterial coatings of prolonged action for cardioimplants is of great scientific and social importance.Based on chitosan and a newly synthesized compound of the fluoroquinoline series 5-dimethylaminomethyl-7-(2,2,2-trifluoro-1-hydroxy-1-trifluoromethyl-ethyl)-quinoline-8-ola (AFOQ) a new composite has been obtained. A comparative analysis of its antimicrobial activity with other chitosan composites containing the antibiotics tetracycline, vancomycin and ciprofloxacin used in modern medicine has been carried out. The high efficiency of the new composite in suppressing the growth of S.Aureus is shown. The possibility of obtaining chitosan nanoparticles doped with AFOQ for their use as an "intelligent" coating of bioprostheses of heart valves, including with the use of carbonic acid, has been established.An approach has been found that makes it possible to form a hybrid biomatrix based on a xenogenic pericardium stabilized with glutaraldehyde (GA) with a polymer "screen" of chitosan nanoparticles covalently bound to it, as nano (micro)containers with antimicrobial agents. Stable chitosan nanoparticles doped with AFOQ were obtained by ion gelling, which is confirmed by a high value of the zeta potential (|ζ|~45 mV). Using high-resolution microscopy, an ultrathin coating of polymer spherical nanoparticles (~70 nm) with high adhesion to collagen fibrils has been identified. The results obtained show the possibility of implementing a "smart" antimicrobial response of this bio-coating induced by a change in the pH of the medium due to a change in the conformation (unwinding) of chitosan polymer nanoparticles and the release of acidic agents in the case of pathogen growth on its surface.