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

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.

Green and Solvent-Free Supercritical CO2-Assisted Production of Superparamagnetic Graphene Oxide Aerogels: Application as a Superior Contrast Agent in MRI

“…Moreover, in almost all the published examples, the composite involves rGO instead of GO. Values of r 2 from 10 to 120 mM –1 ·s –1 have been reported for SPIONs@rGO composites. ,− Values of r 2 > 250 mM –1 ·s –1 are claimed for systems in which the NPs are neatly clustered on the surface of rGO . Only a few publications report r 2 data for SPIONs@GO materials, with values of in the range of 75–145 mM –1 ·s –1 . ,, In this study, the reason behind c Fe 3 O 4 @GO exhibiting a higher relaxivity value than Fe 3 O 4 @GO (even though both composites have similar M s values) is related with the characteristics of the clusters formed by NP aggregation on the surface of the GO matrix.…”

“…However, aggregation also causes precipitation and shortening of circulation time in blood. To achieve enhanced MRI contrast and better biocompatibility and physiological stability, the magnetic materials can be constructed by the controlled clustering of the NPs on a surface, e.g., that of GO sheets. , To prove the rationality of this idea in the prepared composites, Fe 3 O 4 @GO or c Fe 3 O 4 @GO samples were tested as MRI contrast agents. A six-well plate containing Fe 3 O 4 @GO or c Fe 3 O 4 @GO suspended in agar with different iron concentrations was imaged using a 3T MRI instrument (Figure a).…”

“…To achieve enhanced MRI contrast and better biocompatibility and physiological stability, the magnetic materials can be constructed by the controlled clustering of the NPs on a surface, e.g., that of GO sheets. 61,62 To prove the rational of this idea in the prepared composites, for SPIONs@rGO composites. 47,[60][61][62] Values of r 2 > 250 mM -1 •s -1 are claimed for systems in which the NPs are neatly clustered on the surface of rGO.…”

“…61,62 To prove the rational of this idea in the prepared composites, for SPIONs@rGO composites. 47,[60][61][62] Values of r 2 > 250 mM -1 •s -1 are claimed for systems in which the NPs are neatly clustered on the surface of rGO. 60 Only few publications report r 2 data for SPIONs@GO materials, with values of in the range of 75-145 mM -1 •s -1 .…”

Tuning the Nature of N-Based Groups From N-Containing Reduced Graphene Oxide: Enhanced Thermal Stability Using Post-Synthesis Treatments

“…Therefore, it is possible to modify these properties by tailoring its electronic structure. This might be achieved by chemical modifications of the graphene lattice [ 7 , 8 , 9 , 10 ], as well as by the decoration of its basal plane with inorganic nanoparticles leading to nanocomposites with applications in MRI [ 11 ], antimicrobial/antibacterial agents [ 12 , 13 ], cathode material for batteries [ 14 ] and biosensors [ 15 ], to name a few.…”