Surface Modification Of Magnetic Nanoparticles Research Articles

New Types of Magnetic Nanoparticles for Stimuli-Responsive Theranostic Nanoplatforms.

Magnetic nanomaterials have played a crucial role in promoting the application of nanotechnology in the biomedical field. Although conventional magnetic nanomaterials such as iron oxide nanoparticles (NPs) are used as biosensors, drug delivery vehicles, diagnostic and treatment agents for several diseases, the persistent pursuit of high-performance technologies has prompted researchers to continuously develop new types of magnetic nanomaterials such as iron carbide NPs. Considering their potential application in biomedicine, magnetic NPs responsive to exogenous or endogenous stimuli are developed, thereby enhancing their applicability in more complex versatile scenarios. In this review, the synthesis and surface modification of magnetic NPs are focused, particularly iron carbide NPs. Subsequently, exogenous and endogenous stimuli-responsive magnetic NP-based theranostic platforms are introduced, particularly focusing on nanozyme-based technologies and magnetic NP-mediated immunotherapy, which are emerging stimuli-responsive treatments. Finally, the challenges and perspectives of magnetic NPs to accelerate future research in this field are discussed.

Synthesis and Modification of Magnetic Nanoparticles for Biosensing and Bioassay Applications: A Review

Biosensors are analytical devices that use biological interactions to detect and quantify single molecules, clinical biomarkers, contaminants, allergens, and microorganisms. By coupling bioreceptors with transducers, such as nucleic acids or proteins, biosensors convert biological interactions into electrical signals. Electrochemical and optical transductions are the most widely used methods due to their high detection capability and compatibility with miniaturization. Biosensors are valuable in analytical chemistry, especially for health diagnostics, as they offer simplicity and sensitivity. Despite their usefulness, challenges persist in immobilizing biorecognition elements on the transducer surface, leading to issues such as loss of sensitivity and selectivity. To address these problems, the introduction of nanomaterials, in particular magnetic nanoparticles (MNPs) and magnetic beads, has been implemented. MNPs combine their magnetic properties with other interesting characteristics, such as their small size, high surface-to-volume ratio, easy handling, and excellent biocompatibility, resulting in improved specificity and sensitivity and reduced matrix effects. They can be tailored to specific applications and have been extensively used in various fields, including biosensing and clinical diagnosis. In addition, MNPs simplify sample preparation by isolating the target analytes via magnetic separation, thus reducing the analysis time and interference phenomena and improving the analytical performance of detection. The synthesis and modification of MNPs play a crucial role in adjusting their properties for different applications. This review presents an overview of the synthesis and surface modifications of magnetic nanoparticles and their contributions to the development of biosensors and bioassays for their applications across different areas. The future challenges of MNP synthesis and integration in assays are focused on their stability, multiplex detection, simplification and portability of test platforms, and in vivo applications, among other areas of development.

Development of ε-poly(L-lysine) carbon dots-modified magnetic nanoparticles and their applications as novel antibacterial agents.

Magnetic nanoparticles (MNPs) are widely applied in antibacterial therapy owing to their distinct nanoscale structure, intrinsic peroxidase-like activities, and magnetic behavior. However, some deficiencies, such as the tendency to aggregate in water, unsatisfactory biocompatibility, and limited antibacterial effect, hindered their further clinical applications. Surface modification of MNPs is one of the main strategies to improve their (bio)physicochemical properties and enhance biological functions. Herein, antibacterial ε-poly (L-lysine) carbon dots (PL-CDs) modified MNPs (CMNPs) were synthesized to investigate their performance in eliminating pathogenic bacteria. It was found that the PL-CDs were successfully loaded on the surface of MNPs by detecting their morphology, surface charges, functional groups, and other physicochemical properties. The positively charged CMNPs show superparamagnetic properties and are well dispersed in water. Furthermore, bacterial experiments indicate that the CMNPs exhibited highly effective antimicrobial properties against Staphylococcus aureus. Notably, the in vitro cellular assays show that CMNPs have favorable cytocompatibility. Thus, CMNPs acting as novel smart nanomaterials could offer great potential for the clinical treatment of bacterial infections.

Interaction between Pharmaceutical Drugs and Polymer-Coated Fe3O4 Magnetic Nanoparticles with Langmuir Monolayers as Cellular Membrane Models

Surface modification of magnetic nanoparticles (MNPs) has been reported to play a significant role in determining their interactions with cell membranes. In this research, the interactions between polymer functionalized (chitosan, CHI or diethylamino-ethyl dextran, DEAE-D) Fe3O4 MNPs, pharmaceutical drugs and model cell membranes were investigated by Langmuir isotherms and adsorption measurements. In this study, 1,2-distearoyl-sn-glycerol-3-phosphate (DSPA) phospholipid monolayers were used as cell membrane models. Insertion experiments demonstrate that diclofenac (DCFN) is not absorbed at the air-water interface, whereas triflupromazine (TFPZ) has a MIP (maximum insertion pressure) of 35 m Nm-1. The insertion of composites MNPs:TFPZ or DCFN has larger MIP values, indicating that the MNPs are adsorbed on the monolayer with the drugs. An Fe3O4@CHI:DCFN composite presented an MIP of 39 m Nm-1 and Fe3O4@DEAE-D:DCFN presented an impressive MIP of 67 mNm-1. In the case of TFPZ, the enhancement in the MIP values is also evident, being 42 mNm-1 for Fe3O4@CHI:TFPZ and 40 mNm-1 for Fe3O4@DEAE-D:DCFN composite. All MNPs:drugs composites have MIP values greater than commonly accepted membrane pressure values, indicating that MNPs:drugs can penetrate a cellular membrane. The fact that the composite MNPs:drugs present greater MIP values than separated compounds indicates that polymer-coated MNPs can act as good drug delivery systems.

Surface modification of magnetic nanoparticles by bacteriophages and ionic liquids precursors.

Magnetic nanoparticles (MNPs) have recently been a point of interest for many researchers due to their properties. However, the studies on the influence of bacteriophages on the synthesis of MNPs seem to be lacking. Furthermore, bacteriophage-modified MNPs have not been combined with n-alkyl quaternary ammonium ionic liquid precursors (QAS). In this study, the aim was to assess the influence of two distinctly different bacteriophages (Escherichia phage P1 and Pseudomonas phage Φ6) on MNPs synthesis in the presence or absence of QAS. Synthesized MNPs have been characterized with X-ray diffraction (XRD) and Mössbauer spectroscopy in terms of changes in the crystallographic structure; scanning electron microscopy (SEM) for changes in the morphology; and ζ-potential. Moreover, the sorption parameters and the loss of viability of bacteria that interacted with MNPs have been determined. The sorption of bacteria differs significantly among the tested samples. Furthermore, the viability of the bacteria adsorbed on MNPs varies in the presence of QAS, depending on the length of the n-alkyl chain. The study has revealed that MNPs can be bound with bacteriophages. Mössbauer spectroscopy has also revealed the probable influence of bacteriophages on the formation of crystals. However, these phenomena require further studies.

Design and preparation of proline, tryptophan and poly-l-lysine functionalized magnetic nanoparticles and their radiolabeling with 131I and 177Lu for potential theranostic use

Surface modification of magnetic nanoparticles with poly-l-lysine, proline, and tryptophan was used to design potential theranostic agents for the application in cancer diagnosis and radionuclide-hyperthermia therapy. Characterization of bare and functionalized magnetic nanoparticles was performed in detail. The transparency of the examined magnetic nanoparticles was measured in the non-alternating magnetic field for a complete and better understanding of hyperthermia. For the first time amino acid-functionalized magnetic nanoparticles were labeled with theranostic radionuclides 131I and 177Lu. The specific absorption rate (SAR) procured for poly-l-lysine functionalized magnetic nanoparticles (SAR values of 99.7 W/g at H0 = 15.9 kA/m and resonant frequency of 252 kHz) demonstrated their possible application in magnetic hyperthermia. Poly-l-lysine functionalized magnetic nanoparticles labeled with 177Lu showed the highest radiochemical purity (>99.00 %) and in vitro stability in saline and serum (>98.00 % up to 96 h). The in vivo analysis performed after their intravenous administration in healthy Wistar rats presented good in vivo stability for several days. Encouraging results as well as magnetic and radiochemical properties of 177Lu–PLL-MNPs (80 °C) justify their further testing toward the potential use as theranostic agents for diagnostic and combined radionuclide-hyperthermia therapeutic applications.

Potential efficiency of magnetic mesoporous silica nanoparticles modified with aspartic acid to cationic dye removal from aqueous solution

ABSTRACT This work includes the preparation of Fe3O4 NPs coated with mesoporous silica nanoparticles (MSNs). The combination between two different materials could improve the removal efficiency of pollutants from wastewater. The surface modification of magnetic nanoparticles could reduce the agglomeration. The Fe3O4-MSNs surface was modified with aspartic acid liked with the adsorbent surface via hydrophobic linker (1,4-phenylene diisothiocyanate, PDITC) to effectively remove the methylene blue (MB) dye from the contaminated water. The particles size was ranged between 110 and 160 nm, as estimated by SEM and TEM. The surface zeta potential of the surface was found to be negatively at pH above 2.5. The nanosorbent efficiency was evaluated at different conditions such as pH, contact time and initial MB concentration. The maximum adsorbed amount of the MB was estimated to be 135 mg/g at 200 mg/L MB concentration and 80 min contact time. The adsorption isotherm fits with the Langmuir model and pseudo-second-order kinetics.

Facile and tunable method for polymeric surface modification of magnetic nanoparticles via RAFT polymerization: Preparation, characterization, and drug release properties

Herein, the facile and tunable technique for the preparation of novel multi-stimuli-responsive nanocomposites via RAFT polymerization for DOX delivery is reported. The influence of the molecular weight of pH- and thermo-sensitive poly (acrylic acid-co-NIPAM) (PNAx), as a macro-RAFT agent, on the nanocomposites size and drug release rate was investigated. The outcome of this study reveals that macro-RAFT agent with lower molecular weight can be attached to the surface of magnetic nanoparticles with higher content of polymeric layer than can macro-RAFT agent with higher molecular weight. Also, it was observed that the particle size, polymer grafting density, DOX loading capacity, and DOX release rate could well be influenced by the molecular weight of PNAx. The in vitro drug release of doxorubicin was examined in various conditions (pH and temperature) and the results established a strong pH and thermal dependence. The order of drug-loading and releasing level rate for synthesized nanocarriers toward PNAx molecular weight are PNA3 < PNA2 < PNA1. These magnetic nanocarriers displayed excellent biocompatibility, stability, and dispersibility in aqueous solutions. Therefore, experimental data and results showed that nanocarriers synthesized with various molecular weights of PNAx by RAFT polymerization could be deployed for practical biomedicine applications and that the RAFT polymerization ushers in an excellent technique for tunable and facile surface modification of various nanoparticles with distinct sizes and morphologies.

A novel ternary Fe3O4@Fc-GO/PANI nanocomposite for outstanding supercapacitor performance

This work introduced a novel ternary electrode material (Fe3O4@Fc1-GO/PANI2:1) for battery-type supercapacitor applications. This high performance electrode material was designed and synthesized via simple processes that involves a simple co-precipitation of magnetic nanoparticles (MNPs), surface modification of MNPs with ferrocene (Fc) moieties through hydrogen-bonded interaction, and preparation of nanohybrids and nanocomposites via physical mixing strategy. Different appropriate structural analyses were then applied for characterization of the synthesized materials. The supercapacitor properties of the materials were investigated by means of cyclic voltammetry (CV),galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS), tests. After electrochemical evaluations, the Fe3O4@Fc1-GO/PANI2:1nanocomposite was selected as optimal combination. This nanocomposite shows a 640mAh g−1 at 1 A g−1. Also, the selected nanocomposite was exhibited 86.68 % retention of initial capacity after 5000 CV cycles. Finally, this ternary nanocomposite was adopted for symmetric two-electrode system fabrication. The Fe3O4@Fc1-GO/PANI2:1-based symmetric cell delivered a high energy density of 106.2 Wh Kg−1 and a high power density of 6657 W Kg−1. These excellent electrochemical performances can be described to the synergistic effects between nanocomposite components.

A Comparative Study of Iron Oxide Nanoparticles Surface Modified Using Carboxylic Acids

In the last decade nanotechnology has greatly developed in many research fields such as engineering, electronic, biological and many others. They can offer several possibilities to design tools, to create new techniques or improve the already existing ones, to discover innovative applications. Nano-science is one of the most important research and development frontiers in modern science. Nanotechnology is now widely used throughout the pharmaceutical industry, medicine, electronics, robotics, and tissue engineering. For biological and biomedical applications, magnetic iron oxide nanoparticles are the primary choice because of their biocompatibility, super-paramagnetic behavior and chemical stability.&#x0D; The purpose of this work is the design, development and surface modification of magnetic nanoparticles. Naked iron oxide nanoparticles have high chemical activity, toxicity and aggregate in the body fluid therefore providing surface coating for the stability of the magnetic nanoparticles. These protective shells not only stabilize the magnetic iron nanoparticles but also can be used for further functionalization. Here the iron oxide nanoparticles were prepared by co-precipitation method, then this nanoparticle is modified using acids- oleic acid and succinic acid and a comparative study is carried out. The TEM, FTIR and DSC characterization techniques were used to confirm the surface modification. After which, it was found the iron oxide nanoparticle with succinic acid gives a uniform coating of the three and can be used for further functionalization for various applications.

Surface modification of magnetic nanoparticles via admicellar polymerization for selective removal of tetracycline from real water samples

Production of imprinted thin membranes via admicellar polymerization

One-pot surface modification of magnetic nanoparticles using phase-transitioned lysozyme for robust immobilization of enzymes

Enzymes were one-pot immobilized between Fe3O4 nanoparticles and a phase-transitioned lysozyme film, providing a new strategy for enzyme immobilization.

Surface Modification of Magnetic Nanoparticles by Carbon-Coating Can Increase Its Biosafety: Evidences from Biochemical and Neurobehavioral Tests in Zebrafish.

Recently, magnetic nanoparticles (MNPs) have gained much attention in the field of biomedical engineering for therapeutic as well as diagnostic purposes. Carbon magnetic nanoparticles (C-MNPs) are a class of MNPs categorized as organic nanoparticles. C-MNPs have been under considerable interest in studying in various applications such as magnetic resonance imaging, photothermal therapy, and intracellular transportof drugs. Research work is still largely in progress for testing the efficacy of C-MNPs on the theranostics platform in cellular studies and animal models. In this study, we evaluated the neurobehavioral toxicity parameters on the adult zebrafish (Danio rerio) at either low (1 ppm) or high (10 ppm) concentration level of C-MNPs over a period of two weeks by waterborne exposure. The physical properties of the synthesized C-MNPs were characterized by transmission electron microscopy, Raman, and XRD spectrum characterization. Multiple behavior tests for the novel tank, mirror biting, predator avoidance, conspecific social interaction, shoaling, and analysis of biochemical markers were also conducted to elucidate the corresponding mechanism. Our data demonstrate the waterborne exposure of C-MNPs is less toxic than the uncoated MNPs since neither low nor high concentration C-MNPs elicit toxicity response in behavioral and biochemical tests in adult zebrafish. The approach combining biochemical and neurobehavioral approaches would be helpful for understanding C-MNPs association affecting the bioavailability, biosafety, interaction, and uptake of these C-MNPs in the living organism.

Recent advances on magnetic biosorbents and their applications for water treatment

Water pollution threatens environment and human health. Common polymer-based sorbents are used to trap pollutants by these sorbents are difficult to separate from treated water and, in turn, their application is limited. Alternatively, nanomaterials with magnetic features offer the advantage of fast and easy magnetically-assisted separation. Moreover, the surface modification of magnetic nanoparticles with biopolymers enhances their adsorptive capabilities. We review recent developments on magnetic biosorbents for water treatment. We present chemical strategies for the surface modification of magnetic nanoparticles with biopolymers to obtain highly effective, robust and reusable biosorbents. This can be done by two strategies: in situ functionalization and post-synthesis functionalization. Post-synthesis functionalization is done in two distinct stages, the synthesis of the magnetic nanoparticles and the surface functionalization, thus allowing better control of each stage individually. Surface functionalization involves either simple coating or the covalent attachment of the biopolymer chains to the surface. Overall, covalent immobilization of the biopolymer onto the particle’s surface is recommended to ensure successful recycling and reuse of the biosorbents without significant loss of adsorption capacity. Finally, we discuss the performance of several magnetic biosorbents in the uptake of heavy metal species and organic pollutants from water.

A new generation of star polymer: magnetic aromatic polyamides with unique microscopic flower morphology and in vitro hyperthermia of cancer therapy

In this work, a novel magnetic nanocomposite based on aromatic polyamide as a statistical star polymer was designed, characterized and studied in hyperthermia process of cancer therapy. The polymerization reaction was carried out via surface modification of magnetic nanoparticles (Fe3O4 MNPs) using polymerization process by phenylenediamine derivatives and terephthaloyl chloride. Various analytical techniques such as field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy, energy-dispersive X-ray, thermogravimetric and vibrating-sample magnetometer analyses were used to confirm the structure of the prepared nanocomposite. A unique rose flower and sphere morphologies were observed by FE-SEM images by the result of polymerization process and fabrication of the synthetic polymeric strands on the surface of the modified Fe3O4 magnetic cores. The application of this novel magnetic nanocomposite was evaluated in hyperthermia process as a potential method for cancer therapy and its exposure to an external alternating magnetic field. The highest specific absorption rate measured for 0.5 mg/mL of a sample was 191.97 w g−1, and the saturation magnetization value was 4.3 emu g−1.

Curing epoxy with ethylenediaminetetraacetic acid (EDTA) surface-functionalized CoxFe3-xO4 magnetic nanoparticles

In this work, the bulk and surface composition of Fe3O4 supermagnetic nanoparticles were modified for efficient epoxy curing. The bare, ethylenediaminetetraacetic acid (EDTA) capped, and cobalt (Co)-doped EDTA capped Fe3O4 nanoparticles were synthesized electrochemically. The crystalline structure and phase information, surface capping, morphology and magnetization behavior of nanoparticles were studied by X-Ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), field-emission scanning electron microscopy (FE-SEM) and vibrating sample magnetometer (VSM), respectively. A low amount of the prepared nanoparticle (0.1 wt.%) was used in preparation of epoxy nanocomposites. Nonisothermal differential scanning calorimetry (DSC) under different heating rates was performed to study the potential of nanoparticles in curing epoxy resin with an aliphatic amine. The heat release data on nanocomposites suggest that EDTA capped Co-doped Fe3O4 considerably improved the curing reaction between epoxy resin and the curing agent. Calculations based on Cure Index approved qualitatively a shift from Poor to Good cure by concurrent lattice and surface modifications of magnetic nanoparticles. It is bielived that the approach used in this work can pave the way to enhance curability of epoxy nanocomposites by the combined modification of bulk and surface of nanoparticles.

Magnetic nanoparticles decorated with PEGylated curcumin as dual targeted drug delivery: Synthesis, toxicity and biocompatibility study.

The problems associated with hydrophobic anticancer drugs are among the most important challenges to achieve efficient therapeutics for cancer treatment. In this study, PEGylated curcumin was used as the surface modification of magnetic nanoparticles (MNP@PEG-Cur) in order to simultaneously take advantage of magnetic targeting characteristic of nanoparticles and PEG conjugated drug. Curcumin was conjugated through EDC/NHS chemistry to the PEG hydroxyl functional groups, and then physically decorated on the surface of magnetic nanoparticles (MNP). The analysis of the conjugate and nanoparticles by FT-IR, 1HNMR, FE-SEM, TEM, EDX, TGA and VSM confirmed the successful synthesis and proper physicochemical properties of MNP@PEG-Cur nanoparticles. The carrier showed pH dependent drug release profile with higher drug release at acidic media (pH = 5.4) compared to neural condition (pH = 7.4). In addition, LD50 and hemolysis assay confirmed the biocompatibility of MNP@PEG-Cur. The cell viability assay also revealed that neither carrier, nor curcumin-loaded nanoparticles are cytotoxic at physiologic pH (7.4).

Versatile Sulfathiazole-Functionalized Magnetic Nanoparticles as Catalyst in Oxidation and Alkylation Reactions

Catalyst design and surface modifications of magnetic nanoparticles have become attractive strategies in order to optimize catalyzed organic reactions for industrial applications. In this work, silica-coated magnetic nanoparticles with a core-shell type structure were prepared. The obtained material was successfully functionalized with sulfathiazole groups, which can enhance its catalytic features. The material was fully characterized, using a multi-technique approach. The catalytic performance of the as-synthesized material was evaluated in 1) the oxidation of benzyl alcohol to benzaldehyde and 2) the microwave-assisted alkylation of toluene with benzyl chloride. Remarkable conversion and selectivity were obtained for both reactions and a clear improvement of the catalytic properties was observed in comparison with unmodified γ-Fe2O3/SiO2 and γ-Fe2O3. Noticeably, the catalyst displayed outstanding magnetic characteristics which facilitated its recovery and reusability.

Microwave-assisted dextran modification and nanoparticle synthesis for application in drug delivery system

Magnetic nanoparticles (MNPs) have attracted significant interest thanks to their small size, supermagnetism and low toxicity. However, with their large surface area, MNPs tend to aggregate and are sensitive to oxidation. To overcome this drawback, one of the solutions is surface modification of MNPs using many kinds of coating materials. Among them, carboxymethyl dextran is commonly used due to its high density of carboxymethyl groups which provide negative charge for stabilizing the ferrofluid and are available for attaching bioactive molecules. In this study we describe new methods of using microwave in carboxymethylation and Fe3O4 MNPs synthesis. Curcumin was then loaded on the coated MNPs to form a drug delivery system. The systems then were characterized and tested for cytotoxicity on cancer cells. Results show that our drug delivery system had small size of about 15–20 nm and saturation magnetization of 48.6 emu g−1. Moreover, our system had strong anticancer effect against Hep-G2 and LU-1 cancer cell lines. Therefore, it can be a promising candidate for a novel anticancer treatment.

A review of the preparation and application of magnetic nanoparticles for surface-enhanced Raman scattering

In recent years, the unique properties of magnetic functional nanomaterials have received considerable attentions and show promising applications in separation, detection, diagnosis, catalysis, environment remediation and so on. Specifically, introducing magnetic nanomaterials (MNPs) into traditional sensing techniques greatly simplifies detection operation and improves sensing performances, which makes magnetic nanomaterial-based sensing techniques become a hot research topic. Compared with other sensing techniques such as chromatography, fluorescence, mass spectrum and electrochemistry, surface-enhanced Raman scattering (SERS) displays unique properties of high-sensitivity, fingerprint specificity and nondestructive detection. The introduction of MNPs in SERS has proven to be an efficient way to resolve several critical challenges in practical SERS analysis leading to highly efficient target separation and enrichment, high-sensitive detection and precise outcomes analysis. This makes the MNPs involved SERS analysis a powerful technique with very appealing and promising application in various branches of analytical science. In this review, we first briefly introduced the preparation, encapsulation and surface modification of magnetic nanoparticles, assembly of magnetic nanoparticle–plasmonic substrates and then discussed their applications in SERS analysis, including biomedical application, environmental analysis, food safety and chemical reaction monitoring. Finally, we presented some outlooks on further developments of magnetic nanoparticles in SERS applications.