Barium hexaferrite magnetic fluid: preparation, characterization and the in vitro identification of cytotoxicity and antibacterial activity

As an alternative way to encounter antibiotic-resistant strains of bacteria, we report here a harmless magnetic fluid, which can be targeted to infections using external magnetic field and destroy the target. In this research the ultrafine BaFe12O19 nanoparticles were synthesized through hydrothermal method and for the first time, they were coated by citric acid to form the stable aqueous suspension. Characterization of the prepared (coated) oxide was performed on Furrier transform infrared spectroscopy (FT-IR), powder X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), dynamic light scattering (DLS) and energy-dispersive X-ray spectroscopy (EDS) analysis. The in vitro cytotoxicity as well as the antibacterial activity of the surface modified nano-oxide were measured against eukaryotic cells and samples from both Grams of bacterial strains, respectively. Results showed that the superparamagnetic crystals of barium hexaferrite were successfully surface modified to form a water-based stable magnetic fluid. The magnetic fluid measured to be extremely bio compatible by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) test. Disc diffusion and minimum inhibitory concentration (MIC) methods revealed that the surface modified nano-oxide is fetal for both the Gram-negative Escherichia coli (E. coli) and the Gram-positive Staphylococcus aureus (S. aureus). However, the fatality of the nanoparticles is lower for the Staphylococci strain