Functionalization of γ-Fe2O3@SiO2 nanoparticles using the antiviral drug zidovudine: synthesis, characterization, in vitro cytotoxicity and DNA interaction studies

Abstract

The aim of this study was to design and prepare γ-Fe₂O₃@SiO₂-zidovudine magnetic nanoparticles (MNPs) for magnetic guided drug targeting and biological applications. The magnetic nanoparticles were prepared via a chemical co-precipitation reaction and the surface of the Fe₃O₄ MNPs was coated with silica using the Stöber method via a sol–gel process. These MNPs were functionalized using an antiviral drug “Zidovudine” to achieve water-soluble MNPs for biological applications. FT-IR analysis showed that the MNPs were successfully coated with SiO₂ and zidovudine (AZT). The morphology of the γ-Fe₂O₃@SiO₂-AZT MNPs was found to be spherical with a core–shell structure in the TEM images and showed a uniform size distribution with an average diameter of 25 nm. The cytotoxic and anticancer activities of these MNPs and AZT were investigated against human cancer cells using a MTT colorimetric assay. The cytotoxic effect of the MNPs on the cancer cell lines studied was several times in magnitude higher than that found for AZT. Furthermore, in vitro DNA binding studies were investigated using UV-vis, circular dichroism, and fluorescence spectroscopy. The results for DNA binding illustrated that DNA aggregated on the γ-Fe₂O₃@SiO₂-AZT MNPs via groove binding.