Biological activity comparison between ciprofloxacin loaded to silica nanoparticles and silver nanoparticles for the inhibition of Brucella melitensis

Background and Aim: Brucella melitensis is responsible for brucellosis, a highly contagious, life-threatening disease that has a high impact in low- and middle-income countries. This study aimed to compare silica nanoparticles (SiO-NPs) loaded with ciprofloxacin with silver nanoparticles (AgNPs) loaded with ciprofloxacin to evaluate the possible replacement of silver by silica to enhance biological activity and reduce cytotoxicity. Materials and Methods: SiO-NPs and AgNPs loaded with ciprofloxacin were characterized using ultraviolet spectroscopy, scanning electron microscopy, and dynamic light scattering microscopy for size demonstration and loading efficiency. Both nanoparticles were treated with B. melitensis Rev 1 to evaluate their biological activity. Nanoparticle toxicity was also evaluated using cytotoxicity and hemolysis assays. Results: SiO-NP was found to have a smaller size (80 nm) and higher loading efficiency with polydispersity index and zeta potential of 0.43 and 30.7 mV, respectively, compared to Ag-NP (180 nm and 0.62 and 28.3 mV, respectively). SiO-NP was potent with a minimum inhibitory concentration of 0.043 μg/mL compared to Ag-NP (0.049 μg/mL), with a lower cytotoxicity and hemolysis activity. Conclusion: SiO-NP, as a drug delivery system for ciprofloxacin, has better antimicrobial activity against B. melitensis with lower cytotoxicity and hemolysis activity. These results can be attributed to the enhanced physical characterization and better loading efficiency when compared to Ag-NP.