Development of core-shell nanocomposites containing iron oxide,silica and samarium for potential application in cancer treatments involving brachytherapy and magnetic hyperthermia

Abstract

Nanocomposites formed of natural-origin iron oxide nanoparticles (magnetite and maghemite, Fe₃O₄ and γ-Fe₂O₃, respectively) were processed using the sol-gel process into core-shell structures containing silica and samarium to investigate their potential for applications in cancer treatments combining hyperthermia and brachytherapy. Mössbauer characterization showed that the iron oxides contained 64% magnetite, 18% hematite, 12% maghemite, and exhibit superparamagnetic behavior at room temperature. Transmission electron microscopy determined that the iron oxide particles were smaller than 15 nm, while magnetization was measured at 5 emu/g. Fourier transform infrared indicated the material was formed of Si-O-Si and Fe-O-Si bonds, while X-ray diffraction showed bands of amorphous silica from 5° to 23° and bands of iron oxide phases. X-ray fluorescence indicated 5.17% of incorporated samarium. The nanocomposite suspensions were subjected to an alternating magnetic field and the resulting heat dissipation was measured, falling within the ideal range for hyperthermia applications. Theoretical dosimetric calculation determined significant radioactive activity of 1.68x10^-8 MBq.mg^-1.Φ ^-1 after 24h decay time for ¹⁵³Sm. The characteristics and behavior of these nanocomposites indicate that they may offer promise in applications involving hyperthermia for cancer treatment and a more accessible source for brachytherapy materials.

Keywords:
nanocomposites; sol-gel; iron oxide; samarium; silica; brachytherapy/magnetic hyperthermia; cancer.