Synthesizing and Optimizing Rutile TiO Nanoparticles for Magnetically Guided Drug Delivery.

Introduction: Titanium dioxide nanoparticles (TiO NPs) have shown tremendous potential in targeted drug-delivery applications. Among various mechanisms, magnetically guided transport of drugs is one such technique for the said purpose. TiO NPs being diamagnetic or sometimes exhibiting very weak ferromagnetism can be modified by treating them with suitable magnetic materials.

Methods: Rutile TiO NPs were synthesized and doped with Iron Supplement FericipXT and rare-earth metals like cerium, erbium and neodymium via sol-gel technique. FericipXT-coated rutile TiO NPs were synthesized in three different core-shell ratios (1:3, 1:1 and 3:1). The resulting samples were characterized via X-ray Diffraction (XRD), Vibrating Sample Magnetometer (VSM) and High-Resolution Transmission Electron Microscopy (HR-TEM).

Results: XRD of FericipXT-doped TiO NPs showed a rutile phase for 1% and 3% doping; however, only a small fraction of the maghemite phase was obtained for 5% doping. The XRD plots of Ce-doped, Er-doped and Nd-doped TiO NPs showed a variety of phases of TiO NPs (such as anatase/rutile/mixed) along with the oxide phases of the corresponding rare-earth metal. The presence of various iron titanium oxides and iron oxides was found in core-shell NPs. HR-TEM images confirmed the formation of 1:3, 1:1 and 3:1 core-shell TiO NPs. VSM studies showed that the resulting NPs depicted magnetism in the form of superparamagnetism, ferromagnetism and even paramagnetism.

Discussion: The doping to 3% does not affect the original phase of the resulting TiO NPs as depicted from the XRD; however, a doping of 5% and more resulted in extra phases corresponding to the dopant added. FericipXT was loaded over TiO NPs in amorphous form. Among all the samples synthesized, FericipXT-coated TiO NPs demonstrated the best magnetic ability. It was deduced that coating with a magnetic material drastically improves the magnetic character of the host NPs.