Background. Antimicrobial resistance, particularly multidrug-resistant and extensively drug-resistant strains, poses a major health threat worldwide, causing approximately 1.3 million deaths annually. This trend dictates the need to search for new approaches to the treatment of diseases initiated by strains of antibiotic-resistant microflora. In recent years, one of the promising areas in this area is the study of the anti-infectious activity of nanoparticles, in particular quantum dots (QDs). The mechanisms of anti-infective activity of QDs are determined by their ability to penetrate into the bacterial cell due to their ultra-small size (3–5 nm) and destroy it due to the dosed production of reactive oxygen species, which are coupled with free electron pairs at the external energy level of QDs.
Objective. Evaluation of the pharmacodynamics of metal nanoparticles (QDs) during interaction with a bacterial cell to determine the potential prospects for treating resistant bacterial infections.
Methods. Scanning and transmission electron microscopy was used as a method to study the characteristics of the pharmacodynamics of QDs during interaction with a bacterial cell. The objects of study included 0.001% aqueous solution of InP/ZnSe/ZnS metal QDs (0.1 ml) and a culture of mithicillin-resistant Staphylococcus aureus. The samples were studied in pure form, as well as after mixing with QD solution in equal proportions at time intervals of 1 min., 5 min., 10 min., 30 min., 60 and 120 min. respectively, to assess the characteristics of pharmacodynamics. The criterion for the clinical activity of the samples was the determination of zones of growth inhibition using the disc diffusion method.
Results. During the study, it was found that QDs freely penetrate the cell membrane of a bacterial cell; the first signs of cell destruction with the release of its contents begin to be visualized after 30 minutes of observation; the subsequent dynamics of cell destruction is accompanied by a generalized release of contents into the intercellular space, a change in their shape and volume within 60–120 minutes, which indicates a bactericidal effect. Conclusion. The results obtained demonstrate the promise of further research aimed at studying the technology of combined (conjugated) use of QDs with topical anti-infective agents to increase their anti-infective activity, reduce the risk of selection of strains with multi-drug resistance and the prospect of reducing healthcare costs.

Keywords: quantum dots, infectious diseases, antibiotic resistance