Synthetic Antiferromagnetic Nanoparticles as Potential Contrast Agents in MRI
2014; American Chemical Society; Volume: 8; Issue: 3 Linguagem: Inglês
10.1021/nn406158h
ISSN1936-086X
AutoresRuben Van Roosbroeck, W. Van Roy, Tim Stakenborg, Jesse Trekker, Antoine D’Hollander, Tom Dresselaers, Uwe Himmelreich, Jeroen Lammertyn, Liesbet Lagae,
Tópico(s)MRI in cancer diagnosis
ResumoWe present the top-down synthesis of a novel type of MRI T2 contrast agent with great control over size and shape using a colloidal lithography technique. The resulting synthetic antiferromagnetic nanoparticles (SAF-NPs) yield improved relaxivities compared to superparamagnetic iron oxide alternatives (SPIONs). For T2 weighted imaging, the outer sphere relaxation theory has shown that the sensitivity of a T2 contrast agent is dependent on the particle size with an optimal size that exceeds the superparamagnetic limit of SPIONs. With the use of the interlayer exchange coupling effect, the SAF-NPs presented here do not suffer from this limit. Adjusting the outer sphere relaxation theory for spherical particles to SAF-NPs, we show both theoretically and experimentally that the SAF-NP size can be optimized to reach the r2 maximum. With measured r2 values up to 355 s(-1) mM(-1), our SAF-NPs show better performance than commercial alternatives and are competitive with the state-of-the-art. This performance is confirmed in an in vitro MRI study on SKOV3 cells.
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