Highly stable monodisperse PEGylated iron oxide nanoparticle aqueous suspensions: a nontoxic tracer for homogeneous magnetic bioassays

Abstract

CitationHighly Uniformly sized and shaped iron oxide nanoparticles with a mean size of 25 nm were synthesized via decomposition of ironoleate. High resolution transmission electron microscopy and Mössbauer spectroscopy investigations revealed that the particles are spheres primarily composed of Fe 3 O 4 with a small fraction of FeO. From Mössbauer and static magnetization measurements, it was deduced that the particles are superparamagnetic at room temperature. The hydrophobic particles were successfully transferred into water via PEGylation using nitrodopamine as an anchoring group. IR spectroscopy and thermogravimetric analysis showed the success and efficiency of the phase transfer reaction. After the PEGylation, the particles retained monodisperse and their magnetic core remained intact as proven by photon cross-correlation spectrocopy, ac susceptibility, and transmission electron microscopy. The particle aqueous suspensions revealed an excellent water stability over a month of monitoring and also against temperature up to 40 • C. The particles exhibited a moderate cytotoxic effect on in vitro cultured bone marrow-derived macrophages and no release of inflammatory or anti-inflammatory cytokines. The PEGylated particles were functionalized with Herceptin antibodies via a conjugation chemistry, their response to a rotating magnetic field was studied using a fluxgate-based setup and was compared with the one recorded for hydrophobic and PEGylated particles. The particle phase lag rose after labeling with Herceptin, indicating the successful conjugation of Herceptin antibodies to the particles.

Enhanced MRI T 2 Relaxivity in Contrast-Probed Anchor-Free PEGylated Iron Oxide Nanoparticles

“…These findings reflect that PEG-SPION causes negligible cytotoxicity (~9% of reduction in cell viability) even at iron doses as elevated as 10 mM, which is higher than that typically used in nanoparticle-based MRI [58]. It is noteworthy that under the influence of a static 0.2 T field, the cell viabilities of different line cells (such as human neuronal FNC-B4 and breast carcinoma cells) are unaffected, even at more intense fields (1.5 T) the growth of HeLa cells is unaltered [59].…”

Influence of polyethylene glycol coating on biodistribution and toxicity of nanoscale graphene oxide in mice after intravenous injection

“…[15][16][17][18][19][20] PEG is fixed on nanoparticle surfaces by adsorption or covalent binding. When functionalized with PEG, nanoparticles can avoid serum protein binding and achieve enhanced permeability and retention in tumor model systems.…”

Combining X‐Ray Whole Powder Pattern Modeling, Rietveld and Pair Distribution Function Analyses as a Novel Bulk Approach to Study Interfaces in Heteronanostructures: Oxidation Front in FeO/Fe3O4 Core/Shell Nanoparticles as a Case Study

“…However, in nanoparticle form usually the surface oxidation of FeO to Fe 3 O 4 results in a passivation layer, which to a certain extent prevents, or at least slows down, the full oxidation of the particles. This leads to the characteristic FeO/Fe 3 O 4 core/shell structure in this system, both in cubic and spherical morphologies, and in similar systems (i.e., rock salt/spinel) . Note that oxidation of FeO toward Fe 3 O 4 seems to be more pronounced in spherical particles than in cubic ones .…”

“…Note that FeO/Fe 3 O 4 core/shell nanoparticles are a subject of considerable current interest both due to their appealing magnetic properties (e.g., tunable exchange bias or the presence of both a Néel and a Verwey transitions) and their potential applications (e.g., magnetic hyperthermia, magnetic bioassays, microwave absorbers, anode materials for Li‐ion batteries, or solar hydrogen production via water splitting) …”