Superparamagnetic Fe3 Research Articles

Minimally Invasive Delivery of Percutaneous Ablation Agent via Magnetic Colloidal Hydrogel Injection for Treatment of Hepatocellular Carcinoma.

Percutaneous thermotherapy, a minimally invasive operational procedure, is employed in the ablation of deep tumor lesions by means of target-delivering heat. Conventional thermal ablation methods, such as radiofrequency or microwave ablation, to a certain extent, are subjected to extended ablation time as well as biosafety risks of unwanted overheating. Given its effectiveness and safety, percutaneous thermotherapy gains a fresh perspective, thanks to magnetic hyperthermia. In this respect, an injectable- and magnetic-hydrogel-construct-based thermal ablation agent is likely to be a candidate for the aforementioned clinical translation. Adopting a simple and environment-friendly strategy, a magnetic colloidal hydrogel injection is introduced by a binary system comprising super-paramagnetic Fe3O4 nanoparticles and gelatin nanoparticles. The colloidal hydrogel constructs, unlike conventional bulk hydrogel, can be easily extruded through a percutaneous needle and then self-heal in a reversible manner owing to the unique electrostatic cross-linking. The introduction of magnetic building blocks is exhibited with a rapid magnetothermal response to an alternating magnetic field. Such hydrogel injection is capable of generating heat without limitation of deep penetration. The materials achieve outstanding therapeutic results in mouse and rabbit models. These findings constitute a new class of locoregional interventional thermal therapies with minimal collateral damages.

Novel Magnetic Levitation of Nanoiron Oxide for Dynamically Measuring Crystallinity and Uniformity

This study explores the magnetic levitation (maglev) characteristics of superparamagnetic iron oxides (Fe3 O4 ) used as motor-driven rotors in gyroscopes under low-alternating magnetism. Herein, superparamagnetic Fe3 O4 was synthesized in a nanopowder form using the sol–gel method. The maglev force that stabilizes a rotating gyroscope depends on the rotation speed. This force exhibits a wide range of values. The stability of the synthesized superparamagnetic Fe3 O4 increases with its size. The rotation stability was measured based on the size of a red laser spot and was found to depend on the rotation speed. Under a low magnetic field, superparamagnetic materials exhibit high stability. Herein, the superparamagnetic phase exhibits excellent stability. With increasing rotation speed, the superparamagnetic material exhibits strong magnetization. The nanoiron oxide is used to dynamically measure crystallinity and uniformity. Additionally, inversion recovery shows improved gyrostabilization for the superparamagnetic material.

Magnetic Alignment for Plasmonic Control of Gold Nanorods Coated with Iron Oxide Nanoparticles.

Plasmonic nanoparticles that can be manipulated with magnetic fields are of interest for advanced optical applications, diagnostics, imaging, and therapy. Alignment of gold nanorods yields strong polarization-dependent extinction, and use of magnetic fields is appealing because they act through space and can be quickly switched. In this work, cationic polyethyleneimine-functionalized superparamagnetic Fe3 O4 nanoparticles (NPs) are deposited on the surface of anionic gold nanorods coated with bovine serum albumin. The magnetic gold nanorods (MagGNRs) obtained through mixing maintain the distinct optical properties of plasmonic gold nanorods that are minimally perturbed by the magnetic overcoating. Magnetic alignment of the MagGNRs arising from magnetic dipolar interactions on the anisotropic gold nanorod core is comprehensively characterized, including structural characterization and enhancement (suppression) of the longitudinal surface plasmon resonance and suppression (enhancement) of the transverse surface plasmon resonance for light polarized parallel (orthogonal) to the magnetic field. The MagGNRs can also be driven in rotating magnetic fields to rotate at frequencies of at least 17Hz. For suitably large gold nanorods (148nm long) and Fe3 O4 NPs (13.4nm diameter), significant alignment is possible even in modest (<500Oe) magnetic fields. An analytical model provides a unified understanding of the magnetic alignment of MagGNRs.

An Anti-inflammatory Fe3 O4 -Porphyrin Nanohybrid Capable of Apoptosis through Upregulation of p21 Kinase Inhibitor Having Immunoprotective Properties under Anticancer PDT Conditions.

We report the influence of Fe3 O4 nanoparticles (NPs) on porphyrins in the development of photosensitizers (PSs) for efficient photodynamic therapy (PDT) and possible post-PDT responses for inflicting cancer cell death. Except for Au, most metal-based nanomaterials are unsuitable for clinical applications. The US Food and Drug Administration and other agencies have approved Feraheme and a few other iron oxide NPs for clinical use, paving the way for novel biocompatible immunoprotective superparamagnetic iron oxide nanohybrids to be developed as nanotherapeutics. A water-soluble nanohybrid, referred to here as E-NP, comprising superparamagnetic Fe3 O4 NPs functionalised with tripyridyl porphyrin PS was introduced through a rigid 4-carboxyphenyl linker. As a PDT agent, the efficacy of E-NP toward the AGS cancer cell line showed enhanced photosensitising ability as determined through in vitro photobiological assays. The cellular uptake of E-NPs by AGS cells led to apoptosis by upregulating ROS through cell-cycle arrest and loss of mitochondrial membrane potential. The subcellular localisation of the PSs in mitochondria stimulated apoptosis through upregulation of p21, a proliferation inhibitor capable of preventing tumour development. Under both PDT and non-PDT conditions, this nanohybrid can act as an anti-inflammatory agent by decreasing the production of NO and superoxide ions in murine macrophages, thus minimising collateral damage to healthy cells.

A novel method to synthesize iron oxide nanomaterials: Characterization, properties, and performance on the direct red 80 dye removal from aqueous solution

In this work, iron-based nanomaterials (IONs-1 and IONs-2) were synthesized from zero-valent iron nanoparticles (IONs-0) and characterized. IONs-1 were synthesized from IONs-0 by hydrogen peroxide treatment, followed by calcination at 350 °C. IONs-2 were synthesized from IONs-0 by sequential treatment with hydrogen peroxide and sodium hydroxide, respectively. IONs-1 presented the following phases: superparamagnetic Fe3+ (7%), α-Fe2O3 (17%), and γ- Fe2O3 (76%). IONs-2 presented the following phases: superparamagnetic Fe3+ (5%), γ-Fe2O3 (51%) and Fe3S4 (54%). Through microscopy images, it was possible to verify that the IONs-1 and IONs-2 exhibit, respectively, nanorod and well-defined nanosheets formats. The specific surface areas of IONs-1 and IONs-2 were 85.37 and 223.84 m2 g-1, respectively. IONs-1 and IONs-2 were used to remove Direct Red 80 dye, resulting in about 100% removal.

Next-Generation Polymer Shells for Inorganic Nanoparticles are Highly Compact, Ultra-Dense, and Long-Lasting Cyclic Brushes.

Cyclic poly-2-ethyl-2-oxazoline (PEOXA) ligands for superparamagnetic Fe3 O4 nanoparticles (NPs) generate ultra-dense and highly compact shells, providing enhanced colloidal stability and bio-inertness in physiological media. When linear brush shells fail in providing colloidal stabilization to NPs, the cyclic ones assure long lasting dispersions. While the thermally induced dehydration of linear PEOXA shells cause irreversible aggregation of the NPs, the collapse and subsequent rehydration of similarly grafted cyclic brushes allow the full recovery of individually dispersed NPs. Although linear ligands are densely grafted onto Fe3 O4 cores, a small plasma protein such as bovine serum albumin (BSA) still physisorbs within their shells. In contrast, the impenetrable entropic shield provided by cyclic brushes efficiently prevents nonspecific interaction with proteins.

Synthesis and characterization of photo-responsive magnetic molecularly imprinted microspheres for the detection of sulfonamides in aqueous solution.

A dual responsive molecularly imprinted polymer sensitive to both photonic and magnetic stimuli was successfully prepared for the detection of four sulfonamides in aqueous media. The photoresponsive magnetic molecularly imprinted polymer was prepared by surface imprinting polymerization using superparamagnetic Fe3 O4 nanoparticles functionalized with a silica layer as a support, water-soluble 4-[(4-methacryloyloxy)phenylazo]benzenesulfonic acid as the functional monomer, and sulfadiazine as the template. The magnetic molecularly imprinted polymers showed specific affinity to sulfadiazine and its structural analogs in aqueous media. Upon alternate irradiation at 365 and 440 nm, the quantitative bind and release of the four sulfonamides by magnetic molecularly imprinted polymers occurred. Furthermore, the prepared magnetic molecularly imprinted polymers were used as solid-phase extraction material selectively extracted the four sulfonamides from water samples with good recoveries. Thus, a simple, convenient, and reliable detection method for sulfonamides in the environment based on responsive magnetic molecularly imprinted polymers was successfully established.

Fabricating and Tailoring Polyaniline (PANI) Nanofibers with High Aspect Ratio in a Low-Acid Environment in a Magnetic Field.

In a 0.010 m HCl solution, we successfully transformed irregular polyaniline (PANI) agglomerates into uniform PANI nanofibers with a diameter of 46-145 nm and a characteristic length on the order of several microns by the addition of superparamagnetic Fe3 O4 microspheres in a magnetic field. The PANI morphological evolution showed that the PANI nanofibers stemmed from the PANI coating shell synthesized on the surface of the Fe3 O4 microsphere chains. It was found that the magnetic field could optimize the PANI nanofibers with a narrow diameter size distribution, and effectively suppressed secondary growth. When compared with other microspheres (like silica and polystyrene), only the use of superparamagnetic Fe3 O4 microspheres resulted in the appearance of PANI nanofibers. Attempts to form these high-quality PANI nanofibers in other concentrations of HCl solution were unsuccessful. This deficiency was largely attributed to the inappropriate quantity of aniline cations.

Good hydration and cell-biological performances of superparamagnetic calcium phosphate cement with concentration-dependent osteogenesis and angiogenesis induced by ferric iron.

The multifunctionality of calcium phosphate cement (CPC) can be achieved via co-doping with different metallic ions. Magnetism and hyperthermia have been proposed as potential therapeutic methods in bone healing and anti-osteosarcoma treatment. Iron-doping in biomaterials has been confirmed to meet the clinical requirements for these treatments. Herein, superparamagnetic iron-doped CPC (Fe-CPC) showed improved injectability and compressive strength, increased negative surface charge and accelerated hydration with increasing Fe3+ concentration. The superparamagnetism of Fe-CPC was confirmed through vibrating sample magnetometer (VSM) analysis. Mouse bone marrow stromal cells (mBMSCs) cultured on Fe-CPC disks exhibited better attachment morphology and proliferation, and had an enhancement of osteogenic-related gene expression. Moreover, a series of extracts with different concentrations of Fe3+ in cell culture medium were leaching-prepared to simulate the Fe3+-containing liquid environment around the magnetic biomaterials. The performances of mBMSCs and human umbilical vein endothelial cells (HUVECs) cultured in Fe3+-extracts showed increased proliferation rate in a certain amount of Fe3+. Osteogenesis and angiogenesis induced by Fe3+ were observed, but cytotoxicity in mBMSCs appeared when the concentration of Fe3+ was beyond a critical value. Fe-CPC is supposed to have prospective applications in bone remodeling through the combination of self-setting in situ, injectability, superparamagnetism, osteogenesis, angiogenesis, and osteoconductivity.