Preparation and Properties of Complexes Based on Chitosan-Ag Nanocomposite and Cephalosporin Antibiotics

Aggregatively stable, positively charged (~45 mV) chitosan-Ag nanocomposites with a spherical shape and size up to 60.0 nm were synthesized by the “green chemistry” method via the chemical reduction of silver nitrate with chitosan. Chitosan-Ag/ceftriaxone and chitosan-Ag/cefotaxime complexes containing up to 1.06 ± 0.01 and 1.29 ± 0.03 mg antibiotic/mg chitosan-Ag respectively were obtained. It was found that an increase in the ceftriaxone : chitosan-Ag weight ratio in the reaction mixture from 0.5 to 1.25 leads to an increase in the efficiency of antibiotic binding to nanoparticles from 7.2 ± 0.2 to 71.7 ± 0.2%. With an increase in the cefotaxime : chitosan-Ag ratio in the reaction mixture from 0.5 to 10, the antibiotic binding efficiency decreases from 66.2 ± 1.5 to 13.0 ± 0.7%. The formation of chitosan-Ag/antibiotic complexes was confirmed by infrared (IR) spectroscopy. The effectiveness of the use of the chitosan-Ag/cefotaxime complexes against antibiotic-resistant strains of Escherichia coli and Staphylococcus aureus was established.