Iron Oxide-based Magnetic Nanoparticles Research Articles

Magnetic nanoparticles coated with dimercaptosuccinic acid: development, characterization, and application in biomedicine

This review intends to summarize some of the results achieved in the development of magnetic nanoparticles coated with anionic ligands, specifically dimercaptosuccinic acid applied in the biomedical area. We describe synthetic routes used to produce iron oxide-based magnetic nanoparticles, subsequently coated with DMSA as well as functionalization strategies for specific purposes with polymers, antibodies, and cytokines. Finally, we have collected data on biological interactions of DMSA-coated nanoparticles in vitro and in vivo, in particular cell interaction process, pharmacokinetics, and biodistribution in different animal models and their promising applications in drug delivery, NMR imaging, hyperthermia, nanothermometry, magnetic separation, and bioremediation.

Iron Oxide-based Magnetic Nanoparticles for High Temperature Span Magnetocaloric Applications

ABSTRACTThe magnetocaloric effect of chemically synthesized Mn0.3Zn0.7Fe2O4 superparamagnetic nanoparticles with average crystallite size of 11 nm is reported. The magnitude of the magnetic entropy change (ΔSM), calculated from magnetization isotherms in the temperature range of 30 K to 400 K, increases from - 0.16 J-kg-1K-1 for a field of 1 T to - 0.88 J-kg-1K-1 for 5 T at room temperature. Our results indicate that ΔSM values are much higher than primarily reported values for this class of nanoparticles. ΔSM is not limited to the ferromagnetic-paramagnetic transition temperature; instead, it occurs over a broad range of temperatures, resulting in high relative cooling power.

Thermal potentiation of chemotherapy by magnetic nanoparticles.

Clinical studies have demonstrated the effectiveness of hyperthermia as an adjuvant for chemotherapy and radiotherapy. However, significant clinical challenges have been encountered, such as a broader spectrum of toxicity, lack of patient tolerance, temperature control and significant invasiveness. Hyperthermia induced by magnetic nanoparticles in high-frequency oscillating magnetic fields, commonly termed magnetic fluid hyperthermia, is a promising form of heat delivery in which thermal energy is supplied at the nanoscale to the tumor. This review discusses the mechanisms of heat dissipation of iron oxide-based magnetic nanoparticles, current methods and challenges to deliver heat in the clinic, and the current work related to the use of magnetic nanoparticles for the thermal-chemopotentiation of therapeutic drugs.

Promising iron oxide-based magnetic nanoparticles in biomedical engineering

For the past few decades biomedical engineering has imprinted its significant impact on the map of science through its wide applications on many other fields. An important example obviously proving this fact is the versatile application of magnetic nanoparticles in theranostics. Due to preferable properties such as biocompatibility, non-toxicity compared to other metal derivations, iron oxide-based magnetic nanoparticles was chosen to be addressed in this review. Aim of this review is to give the readers a whole working window of these magnetic nanoparticles in the current context of science. Thus, preparation of magnetic iron oxide nanoparticles with the so-far techniques, methods of characterizing the nanoparticles as well as their most recent biomedical applications will be stated.

Toward improved selectivity of targeted delivery: The potential of magnetic nanoparticles

Magnetic nanoparticles, mostly iron oxide-based nanoparticles, have long been used as contrasting agents in magnetic resonance imaging (MRI) applications, heat mediators in hyperthermia treatments and carriers for targeted drug delivery. Magnetic nanoparticles offer some attractive characteristics for targeted drug delivery such as drug carrying ability, nano-scale dimensions and magnetism-driven selective targeting. In this issue, Escribano et al. demonstrated that iron oxide-based magnetic nanoparticles with an implanted magnet can improve selective targeting to the site of inflammation. This result opens a promising avenue for magnetic drug targeting to inflammatory diseases.

Polyelectrolyte coating of iron oxide nanoparticles for MRI-based cell tracking

Iron oxide-based magnetic nanoparticles (MNPs) offer unique properties for cell tracking by magnetic resonance imaging (MRI) in cellular immunotherapy. In this study, we investigated the uptake of chemically engineered NPs into antigen-presenting dendritic cells (DCs). DCs are expected to perceive MNPs as foreign antigens, thus exhibiting the capability to immunologically sense MNP surface chemistry. To systematically evaluate cellular uptake and T2/T2⁎ MR imaging properties of MNPs, we synthesized polymer-based MNPs by employing layer-by-layer (LbL) technology. Thereby, we achieved modification of particle shell parameters, such as size, surface charge, and chemistry. We found that subcellular packaging of MNPs rather than MNP content in DCs influences MR imaging quality. Increased local intracellular electron density as inferred from transmission electron microscopy (TEM) strongly correlated with enhanced contrast in MRI. Thus, LbL-tailoring of MNP shells using polyelectrolytes that impact on uptake and subcellular localization can be used for modulating MR imaging properties. From the Clinical EditorIn this study, layer-by-layer tailoring of magnetic NP shells was performed using polyelectrolytes to improve uptake by dendritic cells for cell-specific MR imaging. The authors conclude that polyelectrolyte modified NP-s can be used for modulating improving MR imaging quality by increasing subcellular localization.

Glutathione (GSH)-decorated magnetic nanoparticles for binding glutathione-S-transferase (GST) fusion protein and manipulating live cells

Iron oxide-based magnetic nanoparticles (MNP) surface-decorated with glutathione (GSH) via a dopamine anchor bind to human α1-glutathione S-transferase (GST) with high affinity and specificity and are able to separate GST fusion proteins from cell lysates. Both the purified GST and the protein of interest (POI) preserve their innate properties. The conjugate of MNP and the GST fusion protein also enables magnetic manipulation of cells.

The magnetophoretic mobility and superparamagnetism of core-shell iron oxide nanoparticles with dual targeting and imaging functionality

With the goal to achieve highly efficacious MRI-monitored magnetic targeting, a novel drug carrier with dual nature of superior magnetophoretic mobility and superparamagnetism was synthesized. This carrier was specially designed in a core-shell structure. The core was achieved by utilizing a strategy of self-assembly of oppositely charged ultrafine superparamagnetic iron oxide nanoparticles previously prepared. The final particles were formed by coating such cores with carboxymethyldextran (CMD) polymer. By exclusion of non-magnetic materials from the interior part of the particles, this structure maximized the amount of magnetic material and thus yielded a superior magnetophoretic mobility. Such a strategy avoids the challenge of superparamagnetism loss, which would be caused by cores exceeding a critical domain size. Coating the self-assembled core enables the magnetic carrier to be stable upon usage and storage and to be readily linked with drug molecules for therapeutic applications. In vitro characterization showed that these nanoparticles displayed a 3- to 4-fold enhancement in magnetophoretic mobility, and a markedly improved stability when stored in 50% serum as a comparison of conventional iron oxide-based magnetic nanoparticles. Preliminary in vivo studies revealed that the nanoparticles also function well as a contrast enhancer for MR imaging of brain glioma. This technology could lead to the development of a new paradigm of magnetic carriers that meet with the needs of various clinical applications.

Characterization of Protein Clusters of Diverse Magnetic Nanoparticles and Their Dynamic Interactions with Human Cells

Although nanoparticle/protein binding and the cytotoxicity of nanoparticles have been separately reported, there has been no study linking the nature of nanoparticle/protein clusters to cell uptake and the dynamic cellular responses. We report here that water-soluble iron oxide-based magnetic nanoparticles (MNPs) with different sizes and surface chemistry bind different serum proteins in terms of protein identity and quantity without changing the protein secondary structures. Carboxylated MNPs (and aminated one in smaller MNPs) resulted in higher cytotoxicity, and PEG coating reduced both cell uptake and the cytotoxicity. Smaller MNPs (especially the carboxylated one) bind more serum proteins, are much less taken up by cells as compared to larger particles, and yet elicit more dynamic cytotoxic responses. Besides the intrinsic effects of size and surface charge of the water-soluble MNPs, the cellular effects of MNPs/protein clusters were also attributed to the identity and quantity of the adsorbed protein...