Multifunctional Magneto-Au/mSiO2 Core-shell Nanoparticles for Advanced Theranostics: Synthesis and Modeling

Abstract

This paper investigates two types of core-shell nanoparticles with the same superparamagnetic iron oxide (SPIO, γ-Fe2O3) core but different coating layers: mesoporous silica (SPIO@mSiO2) and gold nanoshell (Au-SPIO), respectively. The advantages of forming such core-shell nanostructures to be used in advanced theranostics are to detect brain tumors by using Magnetic Resonance Imaging (MRI), and to assist in their treatment by using drug delivery and photothermal ablation. In this paper, the SPIO@mSiO2 nanoparticles are synthesized at diameters of ~ 40 nm. The Au-SPIO nanoparticles are synthesized at diameters of ~ 50 nm. Both core-shell nanostructures are formed with the same SPIO core ~ 10 nm in diameter. Transmission Electron Microscopy (TEM) is utilized to analyze the core-shell nanostructures of both nanoparticles. The ultimate goal is to form the monodisperse Au-mSiO2-SPIO core-shell nanoparticles and to study their potential performance in advanced theranostics under different shape, size, and surface functional group. In the end, a modeling approach is presented to study their relaxation time for MRI scanning under different sizes of magneto-core. Simulation results show that both Brownian and Neel relaxation govern their movements when the particle size is smaller than 20 nm in diameter. However, for particles with diameters larger than 20 nm, Brownian relaxationtime dominants. doi: 10.12783/SHM2015/126