2 research outputs found
Ultrasmall Iron Oxide Nanoparticles for Biomedical Applications: Improving the Colloidal and Magnetic Properties
A considerable increase in the saturation magnetization, <i>M</i><sub>s</sub> (40%), and initial susceptibility of ultrasmall (<5 nm) iron oxide nanoparticles prepared by laser pyrolysis was obtained through an optimized acid treatment. Moreover, a significant enhancement in the colloidal properties, such as smaller aggregate sizes in aqueous media and increased surface charge densities, was found after this chemical protocol. The results are consistent with a reduction in nanoparticle surface disorder induced by a dissolution–recrystallization mechanism
One-Step Fast Synthesis of Nanoparticles for MRI: Coating Chemistry as the Key Variable Determining Positive or Negative Contrast
Iron oxide nanomaterial
is a typical example of a magnetic resonance
imaging probe for negative contrast. It has also been shown how this
nanomaterial can be synthesized for positive contrast by modification
of the composition and size of the core. However, the role of the
organic coating in the relaxometric properties is largely unexplored.
Here, maghemite nanoparticles with either excellent positive or very
good negative contrast performance are obtained by modifying coating
thickness while the core is kept unchanged. Different nanoparticles
with tailored features as contrast agent according to the coating
layer thickness have been obtained in a single-step microwave-driven
synthesis by heating at different temperatures. A comprehensive analysis
is conducted of how the composition and structure of the coating affects
the final magnetic, relaxometric, and imaging performance. These results
show how the organic coating plays a fundamental role in the intrinsic
relaxometric parameters of iron oxide-based contrast media