Abstract P-8:Fe2O3-SiO2-Au Core-Shell Nanoparticles for Theranostics

Abstract

Background: Core-shell nanoparticles (NPs) Fe3O4-SiO2 covered with Au grains due to their unique magnetic, biological, optical and mechanical properties are promising nanostructured material especially in biomedical field. Magnetic core allows controlling the position of NPs, SiO2 shell makes them biocompatible and decrease magnetostatic interactions between them, and Au NPs on the surface allow creating additional matrix around them and using such systems as controlled nanocontainers in tasks of drug delivery, magnetic resonance imaging and target cancer cell therapy. Methods: Inner magnetic core of the NPs was synthesized using polyol method, a 3-step process which resulting in magnetite NPs with hydrophilic surface. Shell was made by covering Fe3O4 particles in surfactant and growing SiO2 on top of them by sol-gel method. Covering core-shell NPs with 3.5 nm Au seed grains using monosilane and their further growth to control diameter. Structural properties were studied using TEM and Dual Beam SEM. Magnetic properties were investigated using LakeShore VSM 7400 magnetometer. Results: Two samples with different concentration of Au NPs were investigated. SEM observations show that core-shell Fe3O4-SiO2 are spherical with average diameter of 200 nm and Au NPs with diameter of 15 nm are evenly dispersed on their surface. Magnetic measurements showed that different concentration of Au NPs results in different coercive forces of the sample. Decreasing the temperature to 77 K showed up to 6 times increase of coercive force and slight increase in magnetization. Conclusion: Biocompatible magnetic nanoparticles are critical advances in biomedical applications. In this work, we studied the morphology of the samples, demonstrated the change of coercive force of NPs with different Au concentration and investigated their magnetic properties in low temperatures.

Keywords

• magnetic nanoparticles
• biomedicine
• low temperature
• cancer cell therapy