Nitric oxide (NO) releasing-superparamagnetic iron oxide nanoparticles for biomedical applications

In this work, superparamagnetic iron oxide nanoparticles were used a new strategy for nitric oxide (NO) releasing material aimed on biomedical applications. Co-precipitation technique of ferric and ferrous chlorides was used to synthesize magnetic nanoparticles. Mercaptosuccin acid (MSA), a thiol-containing small molecule, was used to coat the nanocrystal surfaces, leading to the formation of water soluble thiolated nanoparticles. MSA-coating magnetic nanoparticles were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) measurements and transmission electron microscopy (TEM). Thiolated iron oxide nanoparticles were found to be superparamagnetic at room temperature. NO was bound to the surface of magnetic nanoparticles through nitrosation of thiol groups, present on the surface of the nanoparticles, by addition of acidified sodium nitrite aqueous solution. Formation of nitrosated magnetic nanoparticles was confirmed by detecting free NO released from nanoparticles by chemiluminescence technique. These results showed that 160 mmolL−1 of NO can be released from an aqueous solution of 3.8 mg of nitrosated MSA-magnetic nanoparticles/mL of water. Real time NO detection of NO release from magnetic nanoparticles indicates that visible light can be used as important tool to modulate the rates of NO from nitrosated-magnetic nanoparticles. Overall, the results show that these particles can be used as smart vehicle to carry and delivery NO in biomedical applications, since the nanoparticles might be guided to the target site under a magnetic field to delivery NO direct to the desired target site.