The aim of the work was to study the antimicrobial effect of the PEGylated antibiotic enrofloxacin, to investigate the state of hematopoiesis, hemostasis, resistance, the antioxidant system in the body, the level of hepatotoxicity and nephrotoxicity when administered intramuscularly to laboratory animals and to compare its creation with the traditional antibiotic.
In the course of the work, research was carried out in several stages. At the beginning of the experiment, together with the scientists of Lviv Polytechnic National University, we conducted PEGylation of the antibiotic enrofloxacin by attaching the carboxyl ends of the antibiotic enrofloxacin to the ends of the polyoxyethylene hydrophilic residues of the PEG-400 nanopolymer. A biphilic macromolecule was formed, which is capable of forming self-stabilized dispersions with nanometer-sized particles of the dispersed phase in aqueous solutions. Stabilization of such particles in an aqueous environment is due to the formation of a structural-mechanical barrier of hydrated polyoxyethylene chains around the nucleus, in which the antibiotic is located. The obtained compound had good solubility in water and was stable. High-performance liquid chromatography showed that the purity of the PEGylated antibiotic enrofloxacin is 98–99%.
At the second stage, the in vitro antimicrobial activity of the PEGyllated antibiotic enrofloxacin and the traditional antibiotic enrofloxacin was studied. To evaluate the antimicrobial action of the studied preparations, the minimum inhibitory concentration was determined for museum reference strains (Staphylococcus aureus ATCC 6538Р, Escherichia coli ATCC 11105) and field strains (Staphylococcus epidermidis, Enterobacter) 15 µg/ml) compared with the traditional substance (0.31 µg/ml). At the same time, for S. aureus ATCC 6538P, the MIC of the antibiotic enrofloxacin both in the traditional and in PEGylated forms was the same (0.31 µg/ml). Also, the MIC of the antibiotic enrofloxacin in the traditional and in the PEGylated form for field gram-positive (S. epidermidis) and gram-negative (Enterobacter) microorganisms showed no difference in bacteriostatic activity.
At the third stage, the effect of PEGylated antibiotic enrofloxacin, traditional antibiotic enrofloxacin, and PEG-400 nanopolymer on the functional state and structure of organs and systems of the animal body was studied. For this, 4 groups of rats were created: a control group and three experimental ones. All rats that were in the experiment, for four days, were intramuscularly injected daily with 0.03 ml of the studied preparations. The content of the antibiotic enrofloxacin in PEGylated and traditional form in the solution was 1.8%. The control group of animals was injected with 0.03 ml of saline.
