Investigation of Commercial Iron Oxide Nanoparticles: Structural and Magnetic Property Characterization.
Ontology highlight
ABSTRACT:
SUBMITTER: Wu K
PROVIDER: S-EPMC7948237 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:Particulate matter (PM) concentration levels in the London Underground (LU) are higher than London background levels and beyond World Health Organization (WHO) defined limits. Wheel, track, and brake abrasion are the primary sources of particulate matter, producing predominantly Fe-rich particles that make the LU microenvironment particularly well suited to study using environmental magnetism. Here we combine magnetic properties, high-resolution electron microscopy, and electron tomography to characterize the structure, chemistry, and morphometric properties of LU particles in three dimensions with nanoscale resolution. Our findings show that LU PM is dominated by 5-500 nm particles of maghemite, occurring as 0.1-2 μm aggregated clusters, skewing the size-fractioned concentration of PM artificially to larger sizes when measured with traditional monitors. Magnetic properties are largely independent of the PM filter size (PM10, PM4, and PM2.5), and demonstrate the presence of superparamagnetic (< 30 nm), single-domain (30-70 nm), and vortex/pseudo-single domain (70-700 nm) signals only (i.e., no multi-domain particles > 1 µm). The oxidized nature of the particles suggests that PM exposure in the LU is dominated by resuspension of aged dust particles relative to freshly abraded, metallic particles from the wheel/track/brake system, suggesting that periodic removal of accumulated dust from underground tunnels might provide a cost-effective strategy for reducing exposure. The abundance of ultrafine particles identified here could have particularly adverse health impacts as their smaller size makes it possible to pass from lungs to the blood stream. Magnetic methods are shown to provide an accurate assessment of ultrafine PM characteristics, providing a robust route to monitoring, and potentially mitigating this hazard.
| S-EPMC9755232 | biostudies-literature
Project description:Nanotechnology has the potential to revolutionize agriculture by developing engineered nanomaterials to be used as biostimulants, fertilizers, pesticides or smart sensors. Seed priming may represent an opportunity for nano-enabled plant technology to match economic, agronomic and environmental needs. This study investigates the effects of seed priming mediated by iron oxide magnetic nanoparticles (MNPs) in plants. We performed a multilevel integrated study to understand the basic interactions between MNPs and seeds in pepper (Capsicum annuum). Moreover, phenotypic, physiological and molecular analyses were performed to elucidate the biological impact of MNPs from seed to plant development. Interestingly, our findings show positive effects of MNPs on vegetative growth and a profound impact on pepper gene expression patterns. Indeed, we found 2,204 differentially expressed transcripts in nanoprimed seeds, most of them involved in plant defence mechanisms, potentially establishing a seed memory that might enhance the plant's capacity to counteract diverse forms of stress. In conclusion, this work provides a comprehensive investigation about nanoparticle-seed interactions with interesting implications for agricultural technology.
2023-11-08 | E-MTAB-13087 | biostudies-arrayexpress
Project description:Magnetic iron oxide nanoparticles have multiple biomedical applications in AC-field hyperthermia and magnetic resonance imaging (MRI) contrast enhancement. Here, two cubic particle suspensions are analyzed in detail, one suspension displayed strong magnetic heating and MRI contrast efficacies, while the other responded weakly. This is despite them having almost identical size, morphology, and colloidal dispersion. Aberration-corrected scanning transmission electron microscopy, electron energy loss spectroscopy, and high-resolution transmission electron microscopy analysis confirmed that the spinel phase Fe3O4 was present in both samples and identified prominent crystal lattice defects for the weakly responding one. These are interpreted as frustrating the orientation of the moment within the cubic crystals. The relationship between crystal integrity and the moment magnitude and dynamics is elucidated for the case of fully dispersed single nanocubes, and its connection with the emergent hyperthermia and MRI contrast responses is established.
| S-EPMC9798828 | biostudies-literature
Project description:New preservation technologies may allow for organ banking similar to blood and biomaterial banking approaches. Using cryoprotective agents (CPAs), aqueous solutions with organic components such as DMSO, propylene glycol, and added salts and sugars, organs can be used to vitrify and store organs at -140 °C. When needed, these organs can be rewarmed in a rapid and uniform manner if CPAs are supplemented with iron oxide nanoparticles (IONPs) in an applied radiofrequency field. Speed and uniformity of warming are both IONP concentration and CPA suspension dependent. Here we present a coating method of small molecule phosphonate linker (PLink) and biocompatible polymer (i.e. polyethylene glycol PEG) that tunes stability and increases the maximum allowable concentration of IONPs in CPA suspension. PLink contains a phosphonate 'anchor' for high irreversible binding to iron oxide and a carboxylic acid 'handle' for ligand attachment. PLink-PEG removes and replaces the initial coating layer of commercially available IONPs (EMG1200 (hydrophobic) and EMG308 (hydrophilic) Ferrotec, Inc., increasing colloidal stability and decreasing aggregation in both water and CPAs, (verified with dynamic light scattering) from minutes (uncoated) to up to 6 days. Heating properties of EMG1200, specific absorption rate (SAR), measured using an applied field of 360 kHz and 20 kA m-1, increased from 20 to 180 W per g Fe with increasing PLink-PEG5000. PEG replacing the initially hydrophobic coating decreased aggregation in water and CPA, consistent with earlier studies on heating performance. Furthermore, although the size is minimized at 0.20 mol PEG per g Fe, heating is not maximized until concentrations above 0.43 mol PEG per g Fe on EMG1200. SAR on hydrophilic EMG308 was preserved at 400 W per g Fe regardless of the amount of PLink added to the core. Herein concentrations of IONP in VS55 (common CPA) significantly above our previous capabilities, sIONP at 10 mg Fe per mL, was reached, 25 mg Fe per mL of 308-PEG5000 and 60 mg Fe per mL of 1200-PEG5000, approaching stock EMG308 in water, 60 mg Fe per mL. Furthermore, at these concentrations cryopreserved Human dermal fibroblast cells were successfully nanowarmed (at applied fields described above), with higher viability as compared to convective rewarming in a water bath and heating rate close to 200 °C min-1, 2.5 times faster than our current system. Using PLink as the coating method allowed for higher concentrations of IONPs to be successfully suspended in CPA without affecting the heating ability. Additionally, the model ligand, PEG, allowed for increased stability over time in nanowarming experiments.
| S-EPMC9116443 | biostudies-literature
Project description:The noteworthy intensification in the development of nanotechnology has led to the development of various types of nanoparticles. The diverse applications of these nanoparticles make them desirable candidate for areas such as drug delivery, coasmetics, medicine, electronics, and contrast agents for magnetic resonance imaging (MRI) and so on. Iron oxide magnetic nanoparticles are a branch of nanoparticles which is specifically being considered as a contrast agent for MRI as well as targeted drug delivery vehicles, angiogenic therapy and chemotherapy as small size gives them advantage to travel intravascular or intracavity actively for drug delivery. Besides the mentioned advantages, the toxicity of the iron oxide magnetic nanoparticles is still less explored. For in vivo applications magnetic nanoparticles should be nontoxic and compatible with the body fluids. These particles tend to degrade in the body hence there is a need to understand the toxicity of the particles as whole and degraded products interacting within the body. Some nanoparticles have demonstrated toxic effects such inflammation, ulceration, and decreases in growth rate, decline in viability and triggering of neurobehavioral alterations in plants and cell lines as well as in animal models. The cause of nanoparticles' toxicity is attributed to their specific characteristics of great surface to volume ratio, chemical composition, size, and dosage, retention in body, immunogenicity, organ specific toxicity, breakdown and elimination from the body. In the current review paper, we aim to sum up the current knowledge on the toxic effects of different magnetic nanoparticles on cell lines, marine organisms and rodents. We believe that the comprehensive data can provide significant study parameters and recent developments in the field. Thereafter, collecting profound knowledge on the background of the subject matter, will contribute to drive research in this field in a new sustainable direction.
| S-EPMC7397295 | biostudies-literature
Project description:Growth factors play an important role in nerve regeneration and repair. An attractive drug delivery strategy, termed "magnetic targeting", aims to enhance therapeutic efficiency by directing magnetic drug carriers specifically to selected cell populations that are suitable for the nervous tissues. Here, we covalently conjugated nerve growth factor to iron oxide nanoparticles (NGF-MNPs) and used controlled magnetic fields to deliver the NGF?MNP complexes to target sites. In order to actuate the magnetic fields a modular magnetic device was designed and fabricated. PC12 cells that were plated homogenously in culture were differentiated selectively only in targeted sites out of the entire dish, restricted to areas above the magnetic "hot spots". To examine the ability to guide the NGF-MNPs towards specific targets in vivo, we examined two model systems. First, we injected and directed magnetic carriers within the sciatic nerve. Second, we injected the MNPs intravenously and showed a significant accumulation of MNPs in mouse retina while using an external magnet that was placed next to one of the eyes. We propose a novel approach to deliver drugs selectively to injured sites, thus, to promote an effective repair with minimal systemic side effects, overcoming current challenges in regenerative therapeutics.
| S-EPMC6163445 | biostudies-literature
Project description:Nanoparticles have gained large interest in a number of different fields due to their unique properties. In medical applications, for example, magnetic nanoparticles can be used for targeting, imaging, magnetically induced thermotherapy, or for any combination of the three. However, it is still a challenge to obtain narrowly dispersed, reproducible particles through a typical lab-scale synthesis when researching these materials. Here, we present a droplet capillary reactor that can be used for the synthesis of magnetic iron oxide nanoparticles. Compared to conventional batch synthesis, the particles synthesized in our droplet reactor have a narrower size distribution and a higher reproducibility. Furthermore, we demonstrate how the particle size can be changed from 5.2 ± 0.9 nm to 11.8 ± 1.7 nm by changing the reaction temperature and droplet residence time in the droplet capillary reactor.
| S-EPMC6142730 | biostudies-literature
Project description:Magnetic nanoparticles of Fe3O4 doped by different amounts of Y3+ (0, 0.1, 1, and 10%) ions were designed to obtain maximum heating efficiency in magnetic hyperthermia for cancer treatment. Single-phase formation was evident by X-ray diffraction measurements. An improved magnetization value was obtained for the Fe3O4 sample with 1% Y3+ doping. The specific absorption rate (SAR) and intrinsic loss of power (ILP) values for prepared colloids were obtained in water. The best results were estimated for Fe3O4 with 0.1% Y3+ ions (SAR = 194 W/g and ILP = 1.85 nHm2/kg for a magnetic field of 16 kA/m with the frequency of 413 kHz). The excellent biocompatibility with low cell cytotoxicity of Fe3O4:Y nanoparticles was observed. Immediately after magnetic hyperthermia treatment with Fe3O4:0.1%Y, a decrease in 4T1 cells' viability was observed (77% for 35 μg/mL and 68% for 100 μg/mL). These results suggest that nanoparticles of Fe3O4 doped by Y3+ ions are suitable for biomedical applications, especially for hyperthermia treatment.
| S-EPMC7497709 | biostudies-literature
Project description:Magnetic iron oxide nanoparticles (MIONs) are among the first generation of nanomaterials that have advanced to clinic use. A broad range of biomedical techniques has been developed by combining the versatile nanomagnetism of MIONs with various forms of applied magnetic fields. MIONs can generate imaging contrast and provide mechanical/thermal energy in vivo in response to an external magnetic field, a special feature that distinguishes MIONs from other nanomaterials. These properties offer unique opportunities for nanomaterials engineering in biomedical research and clinical interventions. The past few decades have witnessed the evolution of the applications of MIONs from conventional drug delivery and hyperthermia to the regulation of molecular and cellular processes in the body. Here we review the most recent development in this field, including clinical studies of MIONs and the emerging techniques that may contribute to future innovation in medicine.
| S-EPMC7441585 | biostudies-literature
Project description:Advances in nanotechnology and microfluidics are enabling the analysis of small amounts of human cells. We tested whether recently developed micro-nuclear magnetic resonance (μNMR) technology could be leveraged for diagnosing pulmonary malignancy using fine needle aspirate (FNA) of primary lesions and/or peripheral blood samples. We enrolled a cohort of 35 patients referred for CT biopsy of primary pulmonary nodules, liver or adrenal masses and concurrently obtained FNA and peripheral blood samples. FNA sampling yielded sufficient material for μNMR analysis in 91% of cases and had a sensitivity and specificity of 91.6% and 100% respectively. Interestingly, among blood samples with positive circulating tumor cells (CTC), μNMR analysis of each patient's peripheral blood led to similar diagnosis (malignant vs benign) and differential diagnosis (lung malignancy subtype) in 100% and 90% (18/20) of samples, respectively. μNMR appears to be a valuable, non-invasive adjunct in the diagnosis of lung cancer.From the clinical editorThe authors of this study established that recently developed micro-nuclear magnetic resonance (μNMR) technology can be leveraged for diagnosing pulmonary malignancy using fine needle aspirate (FNA) of primary lesions and/or peripheral blood samples derived from 35 patients, suggesting practical clinical applicability of this technique.
| S-EPMC3966960 | biostudies-literature