Synthesis and characterization of ciprofloxacin loaded silver nanoparticles and investigation of their antibacterial effect

Ciprofloxacin (CIP) antibiotic was loaded on silver nanoparticles (AgNPs), which were prepared by three different methods to enhance their antibacterial activity against Gram-negative (Escherichia coli) bacteria and Gram-positive (Staphylococcus aureus) bacteria. AgNPs were prepared by using sodium borohydride (NaBH4), lactose and sodium citrate followed by one-year aging, in order to produce a uniform prism shape. Finally, the synthesized AgNPs were functionalized with CIP to form composite of AgNPs-CIP. Various analytical techniques were used to characterize the prepared nanocomposites such as ultraviolet-visible (UV-Vis) absorption spectra, Fourier-transform infrared spectroscopy (FTIR) and transmission electron microscope (TEM). TEM images showed some differences in average particle size of AgNPs and their distribution according to the preparation methods. Disc diffusion method was used to investigate the antibacterial activity of AgNPs-CIP composites. Results showed a significant improvement in antibacterial activity against both classes of bacteria especially for the prism AgNPs-CIP. Owing to nanoprisms vertexes and edges which facilities the penetration of Ag ions into the cell wall. AgNPs-CIP composites exhibited higher antibacterial activity against Gram-positive than Gram-negative bacteria due to the differences in bacteria cell walls compositions between the two types.