American Journal of Nanomaterials. 2014, 2(2), 13-20DOI:
Abstract: Two new magnetic nanoparticles (MNPs) were prepared using magnetic iron oxides with cholesterol and sulphadiazine. These compounds were prepared by coprecipitation methods of the iron oxide (II and III) and then the prepared MNP were incubated with the cholesterol and sulphadiazine. The synthesized compounds were identified using many techniques including TEM, SEM, DLS, and TGA. The results showed the formation of new magnetic nanoparticles; MNP@Cholesterol and MNP@Sulphadiazine. The interaction between the prepared MNPs and xanthine oxidase (XO) was studied as a potential method for the inhibition of its activity, for the extraction of XO from biological fluids or for the immobilization of XO on the surfaces of MNPs. The interaction studies involve incubation of XO solution with the suspension of the prepared MNPs using different concentration of XO solutions and fixed weights of MNPs. Adsorption studies of XO on MNPs showed that the prepared MNPS have the ability to extract suitable amounts of XO from solution. Circular dichroism study of the adsorption of XO on the prepared MNPs showed a significant changes in the secondary structures, namely reduction of the α-helix structure. Furthermore, fluorospectrophotometric study showed changes in the tertiary structure of the XO due to the interaction with the active sites of the prepared MNPs. Kinetic study of the inhibition of XO activity by the prepared MNPs showed a mixed inhibition due to the changes in the original XO enzyme after the interaction with the surfaces. Magnetic Fe3O4 showed the higher inhibition activity followed by MNP@Sulphadiazine and MNP@Choleterol-XO, respectively.