Iron-based Magnetic Nanoparticles Research Articles

Contemporary Progress in the Applications of Iron-based Magnetic Nanoparticles in Multicomponent Synthesis: A Review

Abstract: In recent decades, organic synthetic reactions have advanced towards a greener and sustainable reactions by the usage of magnetic nanoparticles (MNPs). Such nanoparticles can be quickly recovered and reused in various organic syntheses. MNPs are a sustainable methodology while encountering environmental and profitable advantage. Due to their properties, MNPs have broad impacts on multiple fields. For instance, their size and magnetic properties have significant implications for various biomedicine, environmental remediation projects, and catalysis. MNPs are an alternative to conventional materials. These are smaller and have a high surface area that allows them to have copious catalytic sites. Amongst various MNPs, iron-based nanoparticles are being profoundly explored in different multicomponent reactions (MCRs). A convergent reaction, which retains most of the significant atoms of the starting components. This investigation targets to equip its readers a brief appertaining to nanoparticles, their processing, and characterization and summarize the evolution in applications of Iron-based MNPs in multicomponent synthetic procedures since 2010.

Synthesis and properties of alginate-based nanoparticles incorporated with different inorganic nanoparticulate modifiers for enhanced encapsulation and controlled release of favipiravir

Alginate is a naturally occurring polysaccharide that consists of guluronic and mannuronic acid residues. Although it has been widely exploited in drug delivery because of its favorable properties (biocompatibility, ease of processing, and gelling capability under mild conditions), most alginate-based systems show poor sustained-release drug release because of the high erosion rate of alginate-based hydrogels. This study exploited the effect of three inorganic nanoparticulate modifiers (including montmorillonite clay material, silver nanoparticles, and iron-based magnetic nanoparticles) on the encapsulation and controlled release of favipiravir, which served as a model for poorly soluble drugs. Structures of the generated nanoparticles were characterized by using UV–visible spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), and thermogravimetric analysis (TGA) to examine interactions between the loaded drug and the components of the nanoparticles. The incorporation of various nanoparticulate modifiers into alginate-based nanoparticles had little effect on the drug release mechanism, with all modified nanoparticles following a Super Case-II transport mechanism in which the drug release rate was governed by the relaxation of the polymeric chains. However, nanoparticles incorporated with different modifiers show variations in porosity and hydrophilicity. This caused ultimate changes in drug encapsulation efficiency and release sustainability.

Applications of Iron Oxide Nanoparticles against Breast Cancer

Breast cancer is the most common cancer diagnosed in women, with an estimated 12% of women in the United States affected during their lifetime. Researchers have demonstrated that early detection, diagnosis, and treatment are pivotal to increasing survival. The advent of nanotechnology has yielded several novel advances and available modern methods within the clinic to detect and treat breast cancer. Inorganic nanoparticles are broadly utilized for cancer diagnosis and therapeutic purposes. Interestingly, these nanoparticles can also be attached to tumor-specific ligands and used to deliver chemotherapeutic or hormonal agents with high levels of tumor selectivity. Iron oxide nanoparticles are one of the most commonly used nanomaterials, which have attracted much attention to detect and treat breast cancers, owing to their superparamagnetic characteristics. Computerized tomography and magnetic resonance imaging (MRI) utilizing iron-based magnetic nanoparticles are promising approaches for the radiological detection of breast cancer. Here, we discuss the roles and recent applications of iron oxide nanoparticles in diagnosing and treating breast cancer.

Application of iron-based magnetic nanoparticles stabilized with triethanolammonium oleate for theranostics

The novel iron-oxide nanoparticles (NPs) stabilized with triethanolammonium oleate were produced. The specimens were divided into two groups: the top NPs (extracted from the supernatant) and the bottom NPs (nanoparticles sedimented at the bottom of the flask during centrifugation), respectively. The XRD and Mössbauer studies revealed a presence of the Fe3O4 phase in both types of nanoparticles. Furthermore, the formation of maghemite layer on the surface of nanoparticles was observed. Average particle sizes determined from TEM and XRD studies were lower than the superparamagnetic limit for the magnetite NPs. For glycerol dispersions of both types of NPs, when exposed to 100 kHz external magnetic field, a significant heat release was observed. Furthermore, the contrasts of T1- and T2-weighted MR images were significantly dependent on the concentration of NPs in their water solutions. Additionally, the reductions of the relaxation times were different for the top and the bottom NPs. The viability studies of the colon cancer cells have shown low cytotoxicity of both types of NPs due to their coating with triethanolammonium oleate, which confirm the possibility to apply the NPs for MRI-guided hyperthermia. Moreover, the presence of NPs did not cause greatest increase of the number of apoptotic cells in the human dermal fibroblasts’ culture and has stimulated proliferation of those cells, revealing great potential of the NPs in regenerative medicine.Graphical abstract

Synthesis, characterization, and application of phosphotungstic acid supported on iron-based magnetic nanoparticles coated with silica

Magnetic nanoparticles based on magnetite (MNP) are important materials for different research applications, particularly when they are coated with inert phases. For instance, coating them with silica forms MNP@SiO2, which has various uses, including as a support for catalysts because it has surface functional groups that form bonds to a coating layer; the material presents itself with high magnetic susceptibility, turning it easily separable from the reaction in a heterogeneous medium. Herein, magnetite was synthesized and coated with tetraethylorthosilicate (TEOS) and then used to support phosphotungstic acid (H3PW12O40, HPW). The X%HPW/MNP@SiO2 materials were characterized by several techniques, such as EDXRF, XRD, SEM, FT-IR, low temperature N2 physisorption, and pyridine gas adsorption/desorption (Py-TPD) and then applied to the esterification reaction of oleic acid with ethanol. The results successfully indicated the synthesis of the catalysts, keeping the structural and magnetic characteristics of the MNP@SiO2 and providing a good dispersion and integrity of HPW on its surface. In the model reaction, high activity, selectivity (100%), and stability were observed, with yields of 98%, 66% and 54% of ethyl oleate when using 30%, 20% and 10%HPW/MPN@SiO2, respectively, for a reaction time of one hour and an acid to ethanol molar ratio of 1:6. No leaching of the active phase was detected up to four recycles of the best catalyst (30%HPW/MPN@SiO2).

Novel magnetic silk fibroin scaffolds with delayed degradation for potential long-distance vascular repair

Although with the good biological properties, silk fibroin (SF) is immensely restrained in long-distance vascular defect repair due to its relatively fast degradation and inferior mechanical properties. It is necessary to construct a multifunctional composite scaffold based on SF. In this study, a novel magnetic SF scaffold (MSFCs) was prepared by an improved infiltration method. Compared with SF scaffold (SFC), MSFCs were found to have better crystallinity, magnetocaloric properties, and mechanical strength, which was ascribed to the rational introduction of iron-based magnetic nanoparticles (MNPs). Moreover, in vivo and in vitro experiments demonstrated that the degradation of MSFCs was significantly extended. The mechanism of delayed degradation was correlated with the dual effect that was the newly formed hydrogen bonds between SFC and MNPs and the complexing to tyrosine (Try) to inhibit hydrolase by internal iron atoms. Besides, the β-crystallization of protein in MSFCs was increased with the rise of iron concentration, proving the beneficial effect after MNPS doped. Furthermore, although macrophages could phagocytose the released MNPs, it did not affect their function, and even a reasonable level might cause some cytokines to be upregulated. Finally, in vitro and in vivo studies demonstrated that MSFCs showed excellent biocompatibility and the growth promotion effect on CD34-labeled vascular endothelial cells (VECs). In conclusion, we confirm that the doping of MNPs can significantly reduce the degradation of SFC and thus provide an innovative perspective of multifunctional biocomposites for tissue engineering.

Iron-based magnetic nanoparticles for multimodal hyperthermia heating

Localized heat generation using nanoparticles is a promising supplementary technique to the well-established cancer treatments, such as chemotherapy and radiotherapy. Here, we demonstrate that iron carbide (Fe5C2) nanoparticles with a thin carbon shell have the collective magnetothermal and photothermal effects based on the ferromagnetic and photonic properties. When the Fe5C2 nanoparticle suspension is irradiated with a NIR laser (808 nm), it yields unprecedented heating effects. Further, owing to the observed high magnetization and coercivity, the Fe5C2 nanoparticle suspension on exposure to an alternating magnetic field (ACMF) exhibits an enhanced specific absorption rate (SAR) as compared to Fe3O4 nanoparticles of the same size. This significant improvement in the SAR arises from the cooperative contribution from the hysteresis and susceptibility losses. This work also gives quantitative information about the ACMF effects on heating ability as well as provides some guidelines for obtaining enhanced heating activity in nanoparticle suspensions of a given magnetic material.

Effects of fluorodeoxyglucose magnetic nanoparticles on NCI-H727 and SH-SY5Y cancer cells.

We present a report regarding the cytotoxic effects of iron-based magnetic nanoparticles conjugated with fluorodeoxyglucose (FDG-mNPs) on the viability of NCI-H727 and SH-SY5Y cancer cells. MTT assays were performed to determine cell viability in treated cancer cells grown under standard 2D culture conditions. FDG-mNP concentrations of 0.075 mg/mL, 0.15 mg/mL, and 0.3 mg/mL decreased mean cell viability of NCI-H727 cells to 92.5%, 82.9%, and 75% respectively. FDG-mNPs was also shown to have a detrimental effect on the viability of SY5Y cells: a decrease of 5.7%, 18.6%, and 36.4% was found for SY5Y cells treated with 0.075 mg/mL, 0.15 mg/mL, and 0.3 mg/mL concentrations of FDG-mNPs, respectively. When NCI-H727 and SH-SY5Y cancer cells were grown as 3D spheroids, morphology was visibly changed and the number of viable cells was decerased in spheroids treated with FDG-mNPs compared with untreated spheroids. The results of our study demonstrated that FDG-mNP has toxic effects on NCI-H7272 and SY5Y cancer cells, and we conclude that conjugated FDG-mNPs are promising in the development of clinical applications for the destruction of cancer cells.

Green synthesis of a high capacity magnetic polymer nanocomposite sorbent based on the natural products for removal of Reactive Black 5

ABSTRACTCumin seeds extract containing plant polyphenols was used as a reducing agent forthe preparation of iron-based magnetic nanoparticles. Then, functionalised magnetic nanoparticles (FMNPs) and chitosan were used to synthesise a novel magnetic polymeric nanocomposite (MPNC) with high efficiency and fast sorption kinetics for Reactive Black 5 removal. FMNPs and MPNC were characterised by Fourier transform infrared, vibrating sample magnetometer, field emission scanning electron microscopy, X-ray diffraction, and Zeta potential. The functionalised magnetic nanoparticles had a spherical shape with the size in the range of 22–38 nm that was covered with chitosan. The zeta potential of MPNC was +59.7 mV. Thepresence of Fe3O4 nanoparticles in MPNC sorbent and its crystalline structure was confirmed by FTIR and XRD, respectively. Results showed that the synthesised sorbent has an excellent sorption behaviour for Reactive Black 5 at room temperature and pH range of 5.5–6.5. The time required to reach equilibrium for various concentrations of Reactive Black 5 was ~ 100 seconds, and a 120 mg L−1of dye solution was 92% decolourised within this time. Experimental data were best fitted to the semi-first-order kinetics and Halsey thermodynamic models. The sorbent maximum capacity was 989.9 mg g−1.

Papain grafted into the silica coated iron-based magnetic nanoparticles ‘IONPs@SiO2-PPN’ as a new delivery vehicle to the HeLa cells

The present study aims at engineering, fabrication, characterization, and qualifications of papain (PPN) conjugated SiO2-coated iron oxide nanoparticles ‘IONPs@SiO2-PPN’. Initially fabricated iron oxide nanoparticles (IONPs) were coated with silica (SiO2) using sol–gel method to hinder the aggregation and to enhance biocompatibility. Next, PPN was loaded as an anticancer agent into the silica coated IONPs (IONPs@SiO2) for the delivery of papain to the HeLa cancer cells. This fabricated silica-coated based magnetic nanoparticle is introduced as a new physiologically-compatible and stable drug delivery vehicle for delivering of PPN to the HeLa cancer cell line. The IONPs@SiO2-PPN were characterized using FT-IR, AAS, FESEM, XRD, DLS, and VSM equipment. Silica was amended on the surface of iron oxide nanoparticles (IONPs, γ-Fe2O3) to modify its biocompatibility and stability. The solvent evaporation method was used to activate PPN vectorization. The following tests were performed to highlight the compatibility of our proposed delivery vehicle: in vitro toxicity assay, in vivo acute systemic toxicity test, and the histology examination. The results demonstrated that IONPs@SiO2-PPN successfully reduced the IC50 values compared with the native PPN. Also, the structural alternations of HeLa cells exposed to IONPs@SiO2-PPN exhibited higher typical hallmarks of apoptosis compared to the cells treated with the native PPN. The in vivo acute toxicity test indicated no clinical signs of distress/discomfort or weight loss in Balb/C mice a week after the intravenous injection of IONPs@SiO2 (10 mg kg−1). Besides, the tissues architectures were not affected and the pathological inflammatory alternations detection failed. In conclusion, IONPs@SiO2-PPN can be chosen as a potent candidate for further medical applications in the future, for instance as a drug delivery vehicle or hyperthermia agent.

Preliminary in-vitro investigation of magnetic fluid hyperthermia in cervical cancer cells

The present study reports auto-tunable temperature sensitive iron-based magnetic nanoparticles fluid synthesized for its application in magnetic fluid hyperthermia. The effect of magnetic field and concentration of the sample is investigated for the induction heating at 350 kHz frequency. The concentration of magnetic fluid and magnetic field was optimized based on the specific absorption of the sample. The cytotoxicity of the optimized magnetic fluid was analyzed on cervical cancer cell line HeLa with and without magnetic field applicator by performing MTT assay. The cytotoxicity assay after induction heating for the magnetic fluid showed cell death up to 75% for 24 h of interaction of fluid with cells. Upon increasing the time of interaction of magnetic fluid to 36 h and for 60 min hyperthermia heating session, almost all cells were found dead. The preliminary analysis revealed significant efficacy of the synthesized magnetic fluid to caused cell death due to hyperthermia of one hour session. In future such type of magnetic fluids can be used for localized treatment of cancer under magnetic field.

Hyperthermic effect in magnetoferritin aqueous colloidal solution

Magnetoferritin is a synthetic derivate of ferritin, an iron storage protein. It is composed of apoferritin shell and iron-based magnetic nanoparticles, providing higher sensitivity to an applied magnetic field allowed to study the hyperthermic effect in magnetoferritin aqueous colloidal solution. Our work presents the first results from measurement of a temperature dependence on time for various magnetic field intensities at a frequency f = 190 kHz. Size distribution of magnetoferritin was performed using dynamic light scattering technique, colloidal stability by zeta potential measurements, morphology by transmission electron microscopy, phase composition of magnetoferritin by X-ray diffraction measurements and magnetic properties using SQUID magnetometer. It was shown, that low hyperthermic effect of magnetoferritin could be related to small sizes of magnetoferritin cores, which polyphase structure was largely composed of lepidocrocite-like mineral.

Microwave-Assisted Reductive Amination with Aqueous Ammonia: Sustainable Pathway Using Recyclable Magnetic Nickel-Based Nanocatalyst

The development of sustainable protocols for the reductive amination is a highly desirable pursuit in the domain of green synthesis. Magnetic nanocatalysts have found a unique niche in chemical synthesis in recent years as the recovery of expensive and/or toxic catalysts after their use are some of the salient features of these greener processes. Herein, we report the application of a recyclable nickel silica eggshell iron-based magnetic nanoparticles (Fe3O4@SiO2-Ni) for the expeditious microwave-assisted reductive amination of aryl aldehydes and ketones in aqueous ammonia; several desired primary amines were produced in good-to-excellent conversions. Extensive characterization of both, fresh and recycled Fe3O4@SiO2-Ni catalysts, showed that the Ni nanoparticles are highly dispersed on the silica shell and that the metal active phase is highly stable as the core–shell morphology is maintained after reaction, indeed the catalyst is recyclable up to six runs without deactivating. A synergic effect between t...

Iron-based magnetic nanoparticles for magnetic resonance imaging

Magnetic resonance imaging (MRI) has been an extensive area of research owing to its depth of penetration for clinical diagnosis. Signal intensity under MRI is related to both T1, spin-lattice relaxation, and T2, spin-spin relaxation. To increase the contrast variability under MRI, several contrast agents are being used, i.e. T1 contrast agents (e.g. gadolinium) and T2 contrast agents (e.g. iron-based magnetic nanoparticles). These contrast agents are administered prior to scanning to increase contrast visibility. They reduce the T1 and T2 relaxation times to produce hyperintense and hypointense signals, respectively. Tunable properties of iron-based magnetic nanoparticles and several coating materials provide a platform to get superb MRI contrast in T2 weighted images. It has been found that contrast enhancement by iron-based magnetic nanoparticles is dependent on the size, shape, composition, surface, and magnetic properties which can be tuned with the synthesis method and coating material. Therefore, understanding the synthesis method and properties of magnetic nanoparticles is vital to contribute to MR signal enhancement which is directing the scientist to design engineered iron-based magnetic nanoparticles. This paper introduces the concept of MRI contrast enhancement. We mainly discuss the synthesis of T2 contrast agents, i.e. iron-based magnetic nanoparticles and the modification of these T2 contrast agents by coating followed by their biomedical applications.

Multifunctional magnetic-responsive hydrogels to engineer tendon-to-bone interface

Photocrosslinkable magnetic hydrogels are attracting great interest for tissue engineering strategies due to their versatility and multifunctionality, including their remote controllability ex vivo, thus enabling engineering complex tissue interfaces. This study reports the development of a photocrosslinkable magnetic responsive hydrogel made of methacrylated chondroitin sulfate (MA-CS) enriched with platelet lysate (PL) with tunable features, envisioning their application in tendon-to-bone interface. MA-CS coated iron-based magnetic nanoparticles were incorporated to provide magnetic responsiveness to the hydrogel. Osteogenically differentiated adipose-derived stem cells and/or tendon-derived cells were encapsulated within the hydrogel, proliferating and expressing bone- and tendon-related markers. External magnetic field (EMF) application modulated the swelling, degradation and release of PL-derived growth factors, and impacted both cell morphology and the expression and synthesis of tendon- and bone-like matrix with a more evident effect in co-cultures. Overall, the developed magnetic responsive hydrogel represents a potential cell carrier system for interfacial tissue engineering with EMF-controlled properties.

Synthesis and Properties of Iron-Based Magnetic Nanoparticles

We have obtained magnetite nanoparticles (MNP) by using chemical coprecipitation of Fe2+ and Fe3+ in water solution. The size of these particles was less than 9 nm, and they possessed corresponding physical and chemical properties. Citric acid was used to stabilize magnetite particles suspension. The acid was affixed to the surface of the particles by adding it in fresh MNP solution during synthesis. Affixing carboxyl groups on the surface of MNP not only does improve particles' dispersion in solvent, but also allows adding further modifications to their surface. The properties of the particles' microstructure and morphology were determined with X-Ray diffraction (XRD) and transmission electron microscopy (TEM), whereas their magnetic properties were determined by means of automated pulse magnetic field analysis equipment. Magnetic measurements have shown that saturation magnetization was 94 emu/g with nanoparticles being at room temperature. We have also researched possible application of these particles as drug carriers by determining doxorubicin sorption capacity on the surface of MNPs. These MNPs have proven to have perspective ability to be a magnetic field-controlled carrier for cancer-treating drugs. The obtained particles can also potentially be used as a contrast medium for MRI.

Gold-Coated Superparamagnetic Nanoparticles for Single Methyl Discrimination in DNA Aptamers.

Au- and iron-based magnetic nanoparticles (NPs) are promising NPs for biomedical applications due to their unique properties. The combination of a gold coating over a magnetic core puts together the benefits from adding the magnetic properties to the robust chemistry provided by the thiol functionalization of gold. Here, the use of Au-coated magnetic NPs for molecular detection of a single methylation in DNA aptamer is described. Binding of α-thrombin to two aptamers conjugated to these NPs causes aggregation, a phenomenon that can be observed by UV, DLS and MRI. These techniques discriminate a single methylation in one of the aptamers, preventing aggregation due to the inability of α-thrombin to recognize it. A parallel study with gold and ferromagnetic NPs is detailed, concluding that the Au coating of FexOy NP does not affect their performance and that they are suitable as complex biosensors. These results prove the high detection potency of Au-coated SPIONs for biomedical applications especially for DNA repair detection.

A Survey on Synthesis Processes of Structured Materials for Biomedical Applications: Iron-based Magnetic Nanoparticles, Polymeric Materials and Polymerization Processes.

Magnetic materials based on iron oxides are extensively designed for several biomedical applications. Heterogeneous polymerization processes are powerful tools for the production of tailored micro-sized and nanosized magneto-polymeric particles. Although several polymerization processes have been adopted along the years, suspension, emulsion and miniemulsion systems deserve special attention due to its ability to produce spherical polymer particles containing magnetic nanoparticles homogeneously dispersed into the polymer thermoplastic matrices. The main objective of this paper is to review the main methods of synthesis of iron-based magnetic nanoparticles and to illustrate how typical polymerization processes in different dispersion medium can be successfully used to produce engineered magnetic core-shell structures. It is exemplified the use of suspension, emulsion and miniemulsion polymerization processes in order to support experimental methodologies required for the production of magnetic polymer particles intended for biomedical applications such as intravascular embolization treatments, drug delivery systems and hyperthermia treatment.

Design considerations of iron-based nanoclusters for noninvasive tracking of mesenchymal stem cell homing.

Stem-cell-based therapies have attracted considerable interest in regenerative medicine and oncological research. However, a major limitation of systemic delivery of stem cells is the low homing efficiency to the target site. Here, we report a serendipitous finding that various iron-based magnetic nanoparticles (MNPs) actively augment chemokine receptor CXCR4 expression of bone-marrow-derived mesenchymal stem cells (MSCs). On the basis of this observation, we designed an iron-based nanocluster that can effectively label MSCs, improve cell homing efficiency, and track the fate of the cells in vivo. Using this nanocluster, the labeled MSCs were accurately monitored by magnetic resonance imaging and improved the homing to both traumatic brain injury and glioblastoma models as compared to unlabeled MSCs. Our findings provide a simple and safe method for imaging and targeted delivery of stem cells and extend the potential applications of iron-based MNPs in regenerative medicine and oncology.

Continuous production of iron-based nanocrystals by laser pyrolysis. Effect of operating variables on size, composition and magnetic response

Well dispersed iron-based magnetic nanoparticles have been prepared by gas phase laser-driven decomposition of iron pentacarbonyl. Agglomeration of the newly synthesized nanoparticles could be avoided by using a liquid collection system in which the exit stream from the laser reactor was bubbled through triethylene glycol (TREG). The effect of different experimental parameters (precursor concentration, laser power, working pressure, residence time) was studied and, by selecting the appropriate conditions, the size of the resulting magnetic nanocrystals could be tuned from ultrasmall (ca. 2.5 nm) to around 12 nm. For nanoparticle sizes around 10 nm and larger a metallic iron core could be preserved. These iron/iron oxide core–shell compositions exhibit very high values of magnetization, 127 emu g−1.