Comparison of paramagnetic iron oxide nanoparticles and magnetic water on the growth of Fusarium oxysporum

The resistance of opportunistic fungal strains has been on a growing trend in the recent years. The toxicity of antimicrobial drugs, development of fungal resistance, and incidence of drug interactions account for the consideration of new drug combinations against fungi. Regarding this, the present study was conducted to perform an in vitro investigation on the effect of paramagnetic iron oxide nanoparticles and magnetic water on Fusarium oxysporum.

The synthesis of paramagnetic iron oxide nanoparticles was conducted in Islamic Azad University, Falavarjan Branch, Falavarjan, Iran, using the co-precipitation method. The antifungal effects of paramagnetic iron oxide nanoparticles and the impact of magnetic water with an intensity of 0.1 Tesla on Fusarium oxysporum were investigated using pur plate technique. Accordingly, the percentage of Fusarium oxysporum growth inhibition was determined.

Findings: The results of X-ray diffraction and electron microscopy showed that iron oxide nanoparticles had a diameter of 20-25 nm with a cubic shape. Based on the results of pur plate technique, 0.1 Tesla magnetic water reduced the diameter of Fusarium oxysporum colonies by more than 49.64% on all days. In addition, the iron oxide nanoparticles at a concentration of 500 ppm inhibited the diameter of the fungal colony by more than 30% on all days. Furthermore, the combination of iron oxide nanoparticles at a concentration of 500 ppm with 0.1 Tesla magnetic water inhibited the growth of fungal colonies by more than 50%. Therefore, the combined method exerted the greatest synergistic impact on reducing the diameter of the fungal colony. Similar to ketoconazole (concentration of 0.003 mg/ml), on the first day, iron oxide nanoparticles with a concentration of 500 ppm inhibited fungal growth.
However, on the twelfth day, 0.1 Tesla magnetic water had a better performance, compared to ketoconazole as a conventional antifungal drug. As the findings indicated, paramagnetic iron oxide nanoparticles with a diameter of 20-25 nm alone and in combination with 0.1 Tesla magnetic water had magnetic antifungal activity against Fusarium oxysporum