Development of silica containing samarium and iron oxide for cancer treatment by brachytherapy and magnetic hyperthermia

Abstract

The combinated therapy for cancer treatment aims to use methods that act through different mechanisms, reducing the probability of developing resistant cancer cells and intolerable side effects. The Magnetic hyperthermia is a modern, directional, and minimally invasive technique that is based on increasing the temperature of tumor cells by means of heat dissipated by particles (subjected) to an alternating magnetic field. Brachytherapy is an oncological treatment where a radioactive source is placed in or near the tumor area for localized treatment of the tumor cells. In this work, silica particles containing iron oxide and samarium (Si-Mag-Sm) were produced by the Sol-Gel method to act as agents for the combined treatment of cancer by hyperthermia and brachytherapy. The iron oxides were characterized by Mössbauer, Zeta Potential, TEM and SEM, and magnetization measurements. The samples were characterized by FTIR, DRX, FRX and TG. The radioactive activity of the elements was estimated by a theoretical dosimetric calculation. XRD, FTIR and XRF techniques indicated synthesis of silica containing samarium and iron oxide. TG indicated loss of adsorbed water between 25 and 150°C, elimination of nitrates and condensation reactions between 160 and 700°C and residual mass of 90%. The dosimetric calculation outlined relevant activity for 153Sm, being higher than the other elements. The morphology of the natural iron oxide observed by TEM showed properties suitable for use in cancer treatment. The Zeta potential showed that the iron oxide has excellent suspension properties for in vivo applications and by the Mössbauer technique, the iron oxide showed superparamagnetic behavior at room temperature.