Microwave-Assisted Synthesis of SPION-Reduced Graphene Oxide Hybrids for Magnetic Resonance Imaging (MRI).

Marina Llenas,Judith Oró-Solé,Stefania Sandoval,Pedro M Costa,Belén Ballesteros,Silvia Lope-Piedrafita,Gerard Tobias,Khuloud T Al-Jamal

doi:10.3390/nano9101364

Abstract

Magnetic resonance imaging (MRI) is a useful tool for disease diagnosis and treatment monitoring. Superparamagnetic iron oxide nanoparticles (SPION) show good performance as transverse relaxation (T2) contrast agents, thus facilitating the interpretation of the acquired images. Attachment of SPION onto nanocarriers prevents their agglomeration, improving the circulation time and efficiency. Graphene derivatives, such as graphene oxide (GO) and reduced graphene oxide (RGO), are appealing nanocarriers since they have both high surface area and functional moieties that make them ideal substrates for the attachment of nanoparticles. We have employed a fast, simple and environmentally friendly microwave-assisted approach for the synthesis of SPION-RGO hybrids. Different iron precursor/GO ratios were used leading to SPION, with a median diameter of 7.1 nm, homogeneously distributed along the RGO surface. Good relaxivity (r2*) values were obtained in MRI studies and no significant toxicity was detected within in vitro tests following GL261 glioma and J774 macrophage-like cells for 24 h with SPION-RGO, demonstrating the applicability of the hybrids as T2-weighted MRI contrast agents.

Highlights

Magnetic resonance imaging (MRI) is one of the most useful diagnostic tools
We report the in situ formation of superparamagnetic iron oxide nanoparticles-reduced graphene oxide (SPION-RGO) hybrids using iron(III) acetylacetonate (Fe(acac)3) as precursor and benzyl alcohol as solvent under microwave treatment
Reduced graphene oxide decorated with superparamagnetic iron oxide nanoparticles (SPION-RGO) was prepared using a microwave-assisted method

Summary

Introduction

Magnetic resonance imaging (MRI) is one of the most useful diagnostic tools. The diagnostic value of MRI can be further expanded by using exogenous contrast agents that improve the resolution of the technique allowing a better interpretation of the acquired images. These agents enhance image contrast by decreasing the longitudinal (T1) and transverse (T2) relaxation time of nearby water protons. Gd3+ based compounds have been proposed as high-performance T1 contrast agents. Their use can lead to heart failure, renal toxicity, deposition into the skin, kidneys and brain. The high toxic response, as consequence for example of the competitive inhibition of biological processes requiring Ca2+, increases the importance of exploring new alternative compounds [14,15,16]

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