Development of Core@Shell γ-Fe2O3@MnxOy@SiO2 Nanoparticles for Hyperthermia, Targeting, and Imaging Applications.

Monodispersed core@shell γ-Fe2O3@MnxOy nanoparticles have been prepared through thermolysis of iron and manganese oleate. Further, these prepared nanoparticles are coated with biocompatible substances such as silica and polyethylene glycol. These particles are highly biocompatible for different cell lines such as normal and cancer cell lines. The nanoparticles are used as hyperthermia agents, and successful hyperthermia treatment in cancer cells is carried out. As compared to γ-Fe2O3@SiO2, γ-Fe2O3@MnxOy@SiO2 shows the enhanced killing of cancer cells through hyperthermia. In order to make them potential candidates for targeting to cancer cells, folic acid (FA) is tagged to the nanoparticles. Fluorescein isothiocyanate (FITC) is also tagged onto these nanoparticles for imaging. The developed γ-Fe2O3@MnxOy@SiO2 nanoparticle can act as a single entity for therapy through AC magnetic field, imaging through FITC and targeting through folic acid simultaneously. This is the first report on this material, which is highly biocompatible for hyperthermia, imaging, and targeting.

Study on the dissolution of ß-precipitates in the Zr-1Nb alloy under the influence of Ne ion irradiation.

The stability of ß-precipitates in the Zr-1Nb alloy has been studied under Ne ion irradiation of energy 250 keV by insitu transmission electron microscope as a function of irradiation dose. The irradiation was carried out up to ∼136 dpa at 573 K. Microstructural investigations have shown that up to ∼38 dpa, precipitates showed an increase in size, and for irradiation doses >38 dpa, the size of the precipitates was noticed to reduce. Post-irradiation energy-dispersive spectrometry of the specimens revealed the Nb concentration throughout the matrix to be ∼0.8-1.5%. Three-dimensional atom probe tomography was also carried out for irradiated specimens to look for the presence of any nanoclusters. However, Nb clustering was not observed in the specimens. It is proposed that the dissolution of the precipitates may be facilitated by an increase in the solubility limit of Nb in Zr caused by irradiation. The solubility limit may increase by the introduction of defects generated by irradiation and by the destabilization of the ß-phase. This may result in back-diffusion of Nb atoms to the matrix by radiation-enhanced diffusion to lower the strain produced by the defects, resulting in the dissolution of the precipitates.