Tailoring the magnetic core of organic-coated iron oxides nanoparticles to influence their contrast efficiency for Magnetic Resonance Imaging

Basini, Martina; Guerrini, Andrea; Cobianchi, M.; Orsini, F.; Bettega, D.; Avolio, Matteo; Innocenti, Claudia; Sangregorio, Claudio; Lascialfari, A.; Arosio, Paolo

doi:10.1016/j.jallcom.2018.08.120

Cited by 23 publications

(18 citation statements)

References 36 publications

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“… ( a ) Longitudinal r 1 and ( b ) transverse r 2 NMRD profiles collected at room temperature in the Larmor frequency range

for the second series of polymer-coated MNPs. For comparison, the relaxivity values of Endorem, as reported by Basini et al, are shown [ 22 ]. …”

Section: Figurementioning

confidence: 99%

“…The efficiency of such particles for diagnostics has indeed been demonstrated to depend on several magnetic (nature of metal ion, spin topology, magnetic anisotropy), morphological/structural (core diameter, shape, crystallinity degree, coating thickness) and chemical (water exchange dynamics, principally due to coating hydrophilicity, permeability and thickness) parameters [ 21 , 22 , 23 , 24 , 25 , 26 ]. Moreover, a great potential of MNPs relies on their reactive surface, which can be exploited for the anchorage of several molecules with different functionalities.…”

Section: Introductionmentioning

confidence: 99%

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Coating Effect on the 1H—NMR Relaxation Properties of Iron Oxide Magnetic Nanoparticles

et al. 2020

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We present a 1H Nuclear Magnetic Resonance (NMR) relaxometry experimental investigation of two series of magnetic nanoparticles, constituted of a maghemite core with a mean diameter dTEM = 17 ± 2.5 nm and 8 ± 0.4 nm, respectively, and coated with four different negative polyelectrolytes. A full structural, morpho-dimensional and magnetic characterization was performed by means of Transmission Electron Microscopy, Atomic Force Microscopy and DC magnetometry. The magnetization curves showed that the investigated nanoparticles displayed a different approach to the saturation depending on the coatings, the less steep ones being those of the two samples coated with P(MAA-stat-MAPEG), suggesting the possibility of slightly different local magnetic disorders induced by the presence of the various polyelectrolytes on the particles’ surface. For each series, 1H NMR relaxivities were found to depend very slightly on the surface coating. We observed a higher transverse nuclear relaxivity, r2, at all investigated frequencies (10 kHz ≤ νL ≤ 60 MHz) for the larger diameter series, and a very different frequency behavior for the longitudinal nuclear relaxivity, r1, between the two series. In particular, the first one (dTEM = 17 nm) displayed an anomalous increase of r1 toward the lowest frequencies, possibly due to high magnetic anisotropy together with spin disorder effects. The other series (dTEM = 8 nm) displayed a r1 vs. νL behavior that can be described by the Roch’s heuristic model. The fitting procedure provided the distance of the minimum approach and the value of the Néel reversal time (τ ≈ 3.5 ÷ 3.9·10−9 s) at room temperature, confirming the superparamagnetic nature of these compounds.

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“… ( a ) Longitudinal r 1 and ( b ) transverse r 2 NMRD profiles collected at room temperature in the Larmor frequency range

for the second series of polymer-coated MNPs. For comparison, the relaxivity values of Endorem, as reported by Basini et al, are shown [ 22 ]. …”

Section: Figurementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Coating Effect on the 1H—NMR Relaxation Properties of Iron Oxide Magnetic Nanoparticles

et al. 2020

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“…The transverse relaxivity coefficient r 2 determined by the slope of the linear fitting curve was 166.5 mM −1 •s −1 for Fe 3 O 4 -Au NPs in water solution. This value is slightly higher than commercial T 2 contrast agents (r 2 ≈ 160 mM −1 •s −1 ) [61].…”

Section: Mri Experimentsmentioning

confidence: 65%

“…The transverse relaxivity coefficient r 2 determined by the slope of the linear fitting curve was 166.5 mM −1 ·s −1 for Fe 3 O 4 -Au NPs in water solution. This value is slightly higher than commercial T 2 contrast agents (r 2 ≈ 160 mM −1 ·s −1 ) [ 61 ]. Interestingly, the transverse relaxivity measured in water nicely agrees with the general trend observed by Efremova et al for a series of Fe 3 O 4 -Au NPs, with similar morphology, and different average size of the magnetic component [ 39 ].…”

Section: Resultsmentioning

confidence: 90%

Multifunctional Fe3O4-Au Nanoparticles for the MRI Diagnosis and Potential Treatment of Liver Cancer

et al. 2020

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Heterodimeric nanoparticles comprising materials with different functionalities are of great interest for fundamental research and biomedical/industrial applications. In this work, Fe3O4-Au nano-heterostructures were synthesized by a one-step thermal decomposition method. The hybrid nanoparticles comprise a highly crystalline 12 nm magnetite octahedron decorated with a single noble metal sphere of 6 nm diameter. Detailed analysis of the nanoparticles was performed by UV-visible spectroscopy, magnetometry, calorimetry and relaxometry studies. The cytotoxic effect of the nanoparticles in the human hepatic cell line Huh7 and PLC/PRF/5-Alexander was also assessed. These Fe3O4-Au bifunctional nanoparticles showed no significant cytotoxicity in these two cell lines. The nanoparticles showed a good theranostic potential for liver cancer treatment, since the r2 relaxivity (166.5 mM−1·s−1 and 99.5 mM−1·s−1 in water and HepG2 cells, respectively) is higher than the corresponding values for commercial T2 contrast agents and the Specific Absorption Rate (SAR) value obtained (227 W/gFe) is enough to make them suitable as heat mediators for Magnetic Fluid Hyperthermia. The gold counterpart can further allow the conjugation with different biomolecules and the optical sensing.

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“…Magnetite nanoparticle (MNP) has been extensively studied for uses in various applications because of its good stability against oxidation and high magnetic responsiveness to an external magnet. Particularly, MNP is of great interest in biomedical technology owing to its biocompatibility and facile synthesis and functionalization, making it to be potentially used in many applications such as magnetically guidable drug delivery, magnetic resonance imaging (MRI), and hyperthermia cancer treatment . However, it tended to aggregate mainly due to dipole‐dipole and magnetic attractive forces, leading to the decrease in the surface area/volume ratio and essentially loss its advantageous properties .…”

Section: Introductionmentioning

confidence: 99%

Water dispersible magnetite nanocluster coated with thermo‐responsive thiolactone‐containing copolymer

Paenkaew

Kajornprai

Rutnakornpituk

2020

Polymers for Advanced Techs

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This work focused on surface modification of magnetite nanoparticle (MNP) with poly(poly(ethylene glycol) monomethyl ether methacylate)-b-(poly(N-isopropylacrylamide)-st-poly(thiolactone acrylamide)), PPEGMA-b-(PNIPAAm-st-PTlaAm), diblock copolymer, synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization to obtain the particles having good water dispersible PPEGMA brushes, thermo-responsive PNIPAAm, and reactive thiolactone groups of PTlaAm.The thiolactone moiety in the copolymer can readily react with amino groups grafted on MNP surface and essentially induced the formation of MNP nanocluster.According to transmission electron microscopy (TEM), the size of the nanocluster ranged between 200 and 500 nm per cluster with 8 to 10 nm in diameter for each particle. Hydrodynamic diameter of the nanocluster significantly decreased as the dispersion temperature increased from 25 C to 45 C due to the shrinkage of thermo-responsive PNIPAAm when crossing its lower critical solution temperature (LCST). This stable nanocluster might be potentially used as a magnetic carrier for control release of entrapped entities with a thermally triggering mechanism. K E Y W O R D S magnetite, nanocluster, thermo-responsive, thiolactone, water dispersible

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Tailoring the magnetic core of organic-coated iron oxides nanoparticles to influence their contrast efficiency for Magnetic Resonance Imaging

Cited by 23 publications

References 36 publications

Coating Effect on the 1H—NMR Relaxation Properties of Iron Oxide Magnetic Nanoparticles

Coating Effect on the 1H—NMR Relaxation Properties of Iron Oxide Magnetic Nanoparticles

Multifunctional Fe3O4-Au Nanoparticles for the MRI Diagnosis and Potential Treatment of Liver Cancer

Water dispersible magnetite nanocluster coated with thermo‐responsive thiolactone‐containing copolymer

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