Optimized PAMAM coated magnetic nanoparticles for simultaneous hyperthermic treatment and contrast enhanced MRI diagnosis

Abstract

We report the synthesis and characterization of multi-functional monodisperse superparamagnetic Magnetic NanoParticles, MNPs, able to act as contrast agents for magnetic resonance and Magnetic Fluid Hyperthermia (MFH) mediators. The investigated samples are constituted of a magnetic core of magnetite and a biocompatible PAMAM coating. We studied two samples with the same magnetic volume but different shape, i.e. spherical and faceted. Despite the relatively large size (MNPs of 20 nm diameter) that generally leads to particles' aggregation and instability, the resulting samples were very

Exploring precision polymers to fine-tune magnetic resonance imaging properties of iron oxide nanoparticles

“…Nuclear magnetic dispersion (NMRD) analysis is a variable field relaxometry technique which is useful in the analysis of magnetic contrast agents. 6,29,30,36 It measures the longitudinal proton relaxation rate enhancement (r1) of a colloidal system at multiple frequencies, providing insight into relaxation properties and the dynamic local environment of water nearby a contrast agent species. Such behaviour is influenced by the magnetic properties of a particle and coupled magnetic interactions with one another and their surroundings.…”

“…Superparamagnetic iron oxide nanoparticles (SPIONs) have been a major research focus for a number of years, with applications ranging catalysis, environmental remediation, magnetically triggered reactions, cell labelling and bioseparation, biosensing, magnetic resonance imaging (MRI), and magnetic hyperthermia therapy. [1][2][3][4][5][6][7] Their diverse applications stem from their unique size-dependent magnetic properties, which are tuneable thanks to their (relatively) straight-forward synthesis and surface modification. 8 Interest in their use as MRI contrast agents has been steady over the past few following this approach, generating exceptionally high relaxation behaviour.…”

Magnetic polymeric nanoassemblies for magnetic resonance imaging-combined cancer theranostics

“…The design combined the effects of magnetic hyperthermia produced by particles under MRI and controlled drug release, and showed that cancer-cell killing was up to almost 90%. Other polymer-coated MNPs were studied by Boni et al 88 They synthesized MNPs by decomposition of iron pentacarbonyl, growth with iron oleate, and further coating with polyamidoamine. The optimized MNPs (faceted-like) exhibited excellent transverse relaxivity (r 2~3 00 mM -1 ⋅s -1 ) that was 2.5-3 times higher than the commercial Endorem and very high specific loss of power up to 900 W⋅g -1 at 262 kHz and 10 kA⋅m -1 .…”

In situ liquid transmission electron microscopy reveals self-assembly-driven nucleation in radiolytic synthesis of iron oxide nanoparticles in organic media

“…The synthesis consists of the thermal decomposition of a metal precursor (e.g., iron stearate, iron oleate or iron pentacarbonyl) in the presence of a surfactant (often oleic acid) in a high boiling point organic solvent. 3 The heating rates, reagents and surfactants molar ratio, water content, and the nature of surfactants and reagents are efficient experimental parameters to achieve nano-objects with narrow size distribution and controlled morphology that are promising for the biomedical field, [4][5][6][7][8][9][10] especially as magnetic resonance imaging contrast agents [11][12][13] or for hyperthermia cancer treatment. [14][15][16][17] Although there is a good understanding of how a high supersaturation regime drives monodispersity in the heating-up thermal decomposition method, 3 the atom-scale and nanoscale mechanisms responsible for the particle size and shape control are mostly a black box.…”