Magnetic Separation System Research Articles

Magnetic field simulation and analysis of superconducting magnetic separator with different magnetic matrices

Superconducting magnetic separation technology leverages strong magnetic fields to separate magnetic from non-magnetic materials, vital for industries like mining, recycling, and water treatment. This study aims to elucidate the impact of various magnetic gathering media on the magnetic field distribution within superconducting magnetic separators through detailed modeling and simulation. Using Infolytica MagNet software, we simulate the magnetic field distribution of a JS-6-102 pilot-scale superconducting magnetic separator, both without media and with different magnetic matrices, such as mesh and rod media. Our results reveal that the presence of magnetic matrices significantly alters the magnetic field distribution, enhancing magnetic induction intensity and affecting field uniformity. We demonstrate that smaller mesh sizes yield more uniform magnetic fields, while larger rod diameters increase magnetic field distortion. These findings contribute to optimizing the design and efficiency of superconducting magnetic separation systems.

Combining rVAR2 and Anti-EpCAM to Increase the Capture Efficiency of Non-Small-Cell Lung Cancer Cell Lines in the Flow Enrichment Target Capture Halbach (FETCH) Magnetic Separation System.

Circulating tumor cells (CTCs) are detected in approximately 30% of metastatic non-small-cell lung cancer (NSCLC) cases using the CellSearch system, which relies on EpCAM immunomagnetic enrichment and Cytokeratin detection. This study evaluated the effectiveness of immunomagnetic enrichment targeting oncofetal chondroitin sulfate (ofCS) using recombinant VAR2CSA proteins (rVAR2) to improve the recovery of different NSCLC cell lines spiked into lysed blood samples. Four NSCLC cell lines-NCI-H1563, A549, NCI-H1792, and NCI-H661-were used to assess capture efficiency. The results demonstrated that the combined use of anti-EpCAM antibody and rVAR2 significantly enhanced the capture efficiency to an average of 88.2% compared with 40.6% when using only anti-EpCAM and 56.6% when using only rVAR2. These findings suggest that a dual-marker approach using anti-EpCAM and rVAR2 can provide a more robust and sensitive method for CTC enrichment in NSCLC, potentially leading to better diagnostic and prognostic outcomes.

Effect of eddy currents on metal fine particles in high gradient magnetic separation using a superconducting magnet

Abstract Dry high gradient magnetic separation is one of the key technologies expected in removing magnetic metal fine particles as contaminations in the production process of various powders. However, the effect of eddy currents on such metal fine particles in dry high gradient magnetic separation has not been adequately explored in previous research. In order to understand this phenomenon more comprehensively, we conducted particle trajectory simulations using a finite element analysis with numerical methods and actual magnetic separation experiments to investigate the influence of eddy currents on magnetic separation efficiency. The results show that for both paramagnetic and diamagnetic metal particles, eddy currents can favourably influence the capture efficiency. Furthermore, these effects depend on the particle size, electrical conductivity, and the rate of change in the magnetic field. Therefore, by taking eddy currents into account, magnetic separation systems can be better optimized and their performance further improved.

A magnetic separation method for isolating and characterizing the biomolecular corona of lipid nanoparticles

Lipid nanoparticle (LNP) formulations are a proven method for the delivery of nucleic acids for gene therapy as exemplified by the worldwide rollout of LNP-based RNAi therapeutics and mRNA vaccines. However, targeting specific tissues or cells is still a major challenge. After LNP administration, LNPs interact with biological fluids (i.e., blood), components of which adsorb onto the LNP surface forming a layer of biomolecules termed the "biomolecular corona (BMC)" which affects LNP stability, biodistribution, and tissue tropism. The mechanisms by which the BMC influences tissue- and cell-specific targeting remains largely unknown, due to the technical challenges in isolating LNPs and their corona from complex biological media. In this study, we present a new technique that utilizes magnetic LNPs to isolate LNP-corona complexes from unbound proteins present in human serum. First, we developed a magnetic LNP formulation, containing >40 superparamagnetic iron oxide nanoparticles (IONPs)/LNP, the resulting LNPs containing iron oxide nanoparticles (IOLNPs) displayed a similar particle size and morphology as LNPs loaded with nucleic acids. We further demonstrated the isolation of the IOLNPs and their corresponding BMC from unbound proteins using a magnetic separation (MS) system. The BMC profile of LNP from the MS system was compared to size exclusion column chromatography and further analyzed via mass spectrometry, revealing differences in protein abundances. This new approach enabled a mild and versatile isolation of LNPs and its corona, while maintaining its structural integrity. The identification of the BMC associated with an intact LNP provides further insight into LNP interactions with biological fluids.

Study on preparation of Fe₃O₄@lapatinib nanoparticles for application as a targeted drug delivery system in the treatment of breast cancer

Systems for targeted drug delivery in the treatment of cancer using nanoparticles are currently of interest to many domestic and foreign scientists. In this work, for application as a target drug delivery system in the treatment of breast cancer Fe3O4@lapatinib nanoparticles were prepared by coprecipitation of solutions of Fe2+ and Fe3+ salts in alkaline, followed by purification in a magnetic separation system. Physicochemical properties of nanoparticles were studied and determined by XRD, TEM, DLS, HPLC, VSM, AAS and zeta potential methods. The results showed that the size of Fe3O4@lapatinib nanoparticles is in the range of 10 to 40 nm, hydrodynamic diameter is 27.4 ± 0.6 nm, saturation magnetization is 39.1 ± 3.1 emu/g, Fe content is 16.35 ± 0.97 mg/ml, lapatinib content is 8.08 ± 0.06 mg/ml, and the zeta potential is -16.2 ± 1.3 mV. Thus, the obtained Fe3O4@lapatinib nanoparticles are fully suitable for targeted drug delivery in the breast cance treatment

Removal of Cationic and Anionic Heavy Metal Ions From Aqueous Phase by a HGMS and Magnetized Zeolite

A magnetic separation study was conducted employing magnetized zeolite and a high gradient magnetic separation system (HGMS) for removal of both cationic and anionic heavy metals. Magnetized zeolite Y was prepared with variable iron contents ranged from 1.2-22.8% based on surface concentration. The magnetized zeolite showed decreased adsorption capacity for cations while the adsorption capacity of the adsorbent for anion increased and the adsorption capacity was proportional to the iron contents. The captured rate of dispersed adsorbents after use for removal of contaminants is a very important factor in water treatment processes. The magnetic separation system recovered more than 98% of magnetized zeolite at 3 T of magnetic field. Current result indicates the combination of magnetized zeolite and HGMS separation could be an efficient alternative for simultaneous removal of cationic and anionic heavy metal from water phase.

Fundamental Study of the Removal of Microplastic Fibers Using Swirling Flow and Magnetic Field

Microplastic fibers (MPFs) derived from laundry wastewater and fishing nets, etc. have been found in the environment around the world, raising concerns about their ecological impact. Particularly for laundry wastewater, some of the MPFs are not removed by sewage plants, and are discharged into the environment. We have studied the removal method of MPFs by magnetic separation in sewage plants, but there were some problems for practical applications such as the desorption of magnetite from MPFs and blockage of magnetic filters. To solve the problems, we proposed a novel magnetic separation system combining swirling flow and opposing magnets. In this study, we investigated whether MPFs can be concentrated by particle trajectory simulations and lab-scale experiments. The simulations and experiments showed similar trends that MPFs can be concentrated by the proposed magnetic separation system. The magnetic separation performance will be improved by using a higher magnetic field of opposed superconducting bulk magnets.

Removal of SUS304 fine particles transformed into martensite by the high gradient magnetic separation under dry condition

The interfusion of impurities such as metallic wear debris has been a major issue in the manufacturing process of foods, medicines and industrial products. Such debris originates with wearing of stainless-steel pipe joints or mechanical moving parts. Since the debris shows ferromagnetic properties by undergoing the strain-induced martensitic transformation of non-magnetic SUS304 (X5CrNi18-10), the magnetic separation system is much efficient to remove such debris from raw materials. In order to study the magnetic separation properties for the martensitic transformation fine particles, the several kinds of magnetic powder with different magnetization were prepared by controlling the amount of martensitic transformation by heat-treating SUS304 powders. The magnetic separation performance was evaluated by the high gradient magnetic separation (HGMS) experiments using the multilayer unidirectional magnetic wire filter under dry condition. The experimental results and FEM particle trajectory simulations revealed that the SUS304 powders transformed into martensite were removed at high speed of 0.1 m/s by the superconducting HGMS in a relatively low magnetic field.

A Massively Parallel Double-Selection Workflow for the Evolution of Molecular Switches Based on Surface-Display in Escherichia coli.

Microbial surface display of proteins is a versatile method for a wide range of biotechnological applications. Here, we present the use of a surface display system in E. coli for the evolution of a riboswitch from an RNA aptamer. To this end a streptavidin-binding peptide (SBP) is displayed at the bacterial surface, which can be used for massively parallel selection using a magnetic separation system. Coupling gene expression from a riboswitch library to the display of SBP hence allows selection of library members that express strongly in the presence of a ligand. As excessive SBP expression leads to bacterial growth inhibition, it can be used to negatively select against leaky riboswitches expressing in the absence of ligand. Based on this principle, we devise a double selection workflow that enables quick selection of functional riboswitches with a comparatively low screening workload. We demonstrate the efficiency of our protocol by re-discovering a previously isolated theophylline riboswitch from a library as well as a novel riboswitch that is similar in performance, but slightly more responsive at low theophylline concentrations. Our workflow is massively parallel and can be applied to the screening or pre-screening of large molecular libraries.

Effects of magnet arrangement on the separation behavior of magnetic particles in high-concentration suspensions based on numerical simulations: Magnetic force induced eddies

ABSTRACT Particle-fluid dynamic behavior significantly influences the separation process of magnetic particles in open-gradient magnetic separation systems. In the present paper, a simplified model of the separation process of magnetic particles in an open-gradient magnetic separation system is developed based on a two-way particle-fluid coupling method. The effects of initial concentration and four magnet arrangements on the particle-fluid kinetic behavior and particle capture efficiency are investigated. The results show that the exclusion zone generated by the lateral concurrent arrangement can induce a double eddy structure and thus contribute to particle capture. This conclusion implies that the generation of eddy structures is not only related to the particle concentration but also to the distribution of the magnetic field. The results also show that the particle capture efficiency increases and then decreases with increasing initial concentration in the presence of a single magnet, i.e. there is an optimal capture concentration.

Numerical study on the effect of turbulence intensity on the separation behavior of magnetic particles under different magnet arrangements

ABSTRACT The crucial problem of magnetic separation is improving the ability to capture magnetic particles in complex fluid flow. This paper develops a numerical model of an open gradient magnetic separation (OGMS) system to study the capture process of magnetic particles in laminar flow and turbulent flow under four kinds of magnet arrangement modes. The particle capture efficiencies of four inlet turbulence intensities are analyzed and compared with that of laminar flow. The results show that the particle capture efficiency of turbulent flow is higher than that of laminar flow under the same inlet velocity distribution in a small Stokes number. Moreover, the particle capture efficiency of high turbulence intensity is significantly higher than that of low turbulence intensity. The results also indicate that the axial alternating arrangement (AAA) can provide a stronger magnetic field, which is beneficial to particle capture.

Electrochemical detection of SARS-CoV-2 based on copper nanoflower-triggered in situ growth of electroactive polymers.

SARS-CoV-2, the pathogen of COVID-19, has introduced massive confirmed cases and millions of deaths worldwide, which poses a serious public health threat. For the early diagnosis of COVID-19, we have constructed an electrochemical biosensor-combined magnetic separation system with copper nanoflower-triggered cascade signal amplification strategy. In the proposed system, magnetic beads were utilized to fabricate the recognition element for capturing the conserved sequence of SARS-CoV-2. As the copper ions source, oligonucleotides modified copper nanoflowers with special layered structure provide numerous catalysts for click chemistry reaction. When target sequence RdRP_SARSr-P2 appears, copper nanoflowers will be bound with magnetic beads, thus prompting the Cu(I)-catalyzed azide-alkyne cycloaddition reaction through the connection of the SARS-CoV-2 conserved sequence. Then, a large number of signal molecules FMMA can be grafted onto the modified electrode surface by electrochemically mediated atom-transfer radical polymerization to amplify the signal for the quantitative analysis of SARS-CoV-2. Under optimal conditions, a linear range from 0.1 to 103 nM with a detection limit of 33.83 pM is obtained. It provides a powerful tool for the diagnosis of COVID-19, which further benefits the early monitoring of other explosive infectious diseases effectively, thus guaranteeing public health safety.

Automated & scalable closed-system platform for cell isolation and activation

The cell therapy field is experiencing rapid growth with several recent regulatory approvals and further therapies in clinical testing. The Gibco™ CTS™ DynaCellect™ Magnetic Separation System and single-use kits have been designed for scalable and robust cell processing with the CTS Dynabeads™ platform. Using the Gibco CTS DynaCellect Cell Isolation Kit with CTS Dynabeads, >85% isolation efficiency of target cells with >95% purity is consistently achieved with no effect on cell viability.

A low-cost approach for recycling large GdBCO bulk superconductors using an infiltration technique with different liquid sources

The high-temperature superconductor has become a research hotspot, because of its high critical temperature, strong trapped flux density, stable suspension characteristics and large magnet levitation force. Single-domain REBa2Cu3O7−δ (REBCO) superconductors, where RE is a rare-earth element such as Y, Gd, Sm or Nd, have wide and potential applications in high-tech fields, such as micro-magnet superconducting maglev trains, superconducting motors and superconducting magnetic separation systems. However, a large number of multi-domain samples are easily produced in the preparation process, resulting in a significantly lower success rate and a significant increase in cost, which restricts their practical applications. Thus, we successfully recycle a series of GdBCO samples by re-supplementing the liquid phase lost in the primary growth process and pre-treating the failed sample as solid-phase source billets, which was proposed by Shi. The growth morphology and superconducting properties of the recycled GdBCO bulk superconductors are investigated in detail in this study. The results show that the key superconductivity properties have been significantly improved, which provides the scientific basis and new ideas for the development of low-cost and highly efficient fabrication yields of REBCO bulk superconductors.

Abstract 21 High-Throughput Blood Separation System for CD34+ Cell Isolation

IntroductionResearch into the therapeutic roles and clinical potential of CD34+ cells is growing [Weissman and Shizuru, Blood. 2008;112(9):3543-3553]. Accordingly, advances in cell isolation methods have risen to meet the research demand. Cord blood banks have a unique opportunity to source CD34+ cells because of their relatively high prevalence in cord blood [Dauber et al. Cytotherapy. 2011;13(4):449-458]. However, current isolation systems are not optimized for processing cord blood, and even blood-compatible systems typically require the blood to be processed before use. FerroBio (www.42bio.com) has developed a magnetic separation system that facilitates scalable, high-volume cell isolation from complex biological fluids, such as blood, without pre-processing. This technology is now being adapted for CD34+ cell isolation from cord blood.ObjectiveIn this study, the conditions in which magnetic beads efficiently bind target cells were explored. The objective of this work was to evaluate optimal blood mixing conditions to bring beads into contact with cells in suspension in the blood. This will allow unmodified cord blood units (CBUs) to flow directly into our apparatus.MethodsThe FerroBio separation process is comprised of three simple steps (Figure 1A). Here, conditions of step 1 were explored to maximize target cell recovery and viability. Variables included type of agitation equipment (Figure 1B), temperature, time, and relative air volume in the blood bag. Recovery and viability were measured via flow cytometry and calculated relative to unprocessed blood from the same CBU.ResultsTwo mixing conditions were identified for maximum recovery of CD34+ cells (Figure 1C, blue bars). While not statistically different from each other, the Drum Roller method only requires one piece of standard equipment, is gentler, and can accommodate multiple CBUs simultaneously. No statistical difference in viability was observed in any conditions (90.7% ± 16.3%, n = 9). Increasing incubation time and the relative amount of air in the bag did not increase recovery (not shown).Figure 1. (A): Overview of the FerroBio Magnetic Separation Process, highlighting step (1) in which magnetic beads are mixed within the CBU to bind the target CD34+ cells. (B): Illustrations of the agitation equipment used to mix the CBU during step (1). (C): The resulting CD34+ recovery (1-way ANOVA, P = .0245). Image credit for panel (A): BioRender.DiscussionThe FerroBio separator can streamline CD34+ cell isolation by processing high blood volumes in a fast, closed system with high recovery rates. Additional studies are under way to evaluate the functionality of the isolated CD34+ cells and efficiency of bead removal.

Development of Novel Magnetic Separation for Paramagnetic Particles Using the Selection Tube

Generally, in order to control and separate of paramagnetic substances by magnetic force, a superconducting high-gradient magnetic separation system applied magnetic field of about 5 T over is required. In this study, we aim to apply a low magnetic field for magnetic separation of paramagnetic substances. We proposed the novel separation method, which is applying a magnetic field to the selection tube, aiming for more precise and easier separation than the conventional High Gradient Magnetic Separation System (HGMS). Selection tube can separate particle mixture into each kinds of particles by the balance of drag force, buoyancy and gravity depending on flow velocity, particle size, shape and specific weight. Since the particles are apparent weightless state, they can be captured with a relatively small magnetic force. Firstly, we showed the effectiveness of Open-Gradient Magnetic Separation (OGMS: applied maximum magnetic flux density 1.3 T) under the selection tube with using colored glass imitated target substance. The experimental results were found to shows good separation efficiency. Eventually, we tested the HGMS obtained by improving the novel magnetic separation method, where a low magnetic field applied (maximum magnetic flux density 0.5 T) is applied to magnetic filters (wire diameter ϕ 0.8mm, 15mesh, SUS430) installed in the selection tube. The effective separation of paramagnetic glass (volume magnetic susceptibility: +3.17×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−4</sup> ) was performed successfully with the combination of the selection tube and the HGMS applied low magnetic field.

Superconducting Magnet Design for a Vertical-Ring High Gradient Magnetic Separation System

This paper describes a design of a Vertical-ring High Gradient Superconducting Magnetic Separation (VHGMS) system for recovery of the magnetic ore and purification of non-metallic minerals. Compared to the conventional design which uses copper wires, using superconducting magnet can help reduce the energy consumption and increase the magnetic field. The first part of this paper introduces the operation margin design of the superconducting magnet. This magnet is wound with NbTi wires and its temperature margin is designed to be higher than 1 K. It generates an average magnetic field above 2 T in the filtering area. The second part of this paper introduces a quench protection circuit implemented in this magnet and post-quench analysis is also presented. Simulation results show that maximum temperature and terminal voltage are within the safe limits. So, the superconducting magnet can be effectively protected from burning-out during a quench. The third part of this paper proposes a novel reinforcement structure for the coil and analyzes the stress status during magnet charging and quench process. The Von mises stresses in the coil and stainless steel are both in allowable stress region and have a large safety margin.

Isolation and culture of rat intestinal mucosal microvascular endothelial cells using immunomagnetic beads

Microvascular endothelial cells (MVECs) have been an important tool in many research fields, while their purification remained challenging, particularly from thin and fragile tissues, such as murine intestinal mucosae. Therefore, we established an immunomagnetic method for isolating rat intestinal mucosal MVECs using an automatic magnetic separation system from the primary cell culture, which was preliminarily purified by the differential adhesion combined with mechanically scraping method. The CD31+ cells were separated and their purity was about 96.5%, which grew into a contact-inhibited cobblestone-like monolayer after about 6-day incubation. Transmission electron microscopy analysis showed the presence of Weibel-Palade bodies. The endothelial tubes formed on Matrigel for about 4-h cultivation. The MVECs could grow well until at least passage 10. Immunofluorescence staining indicated that factor VIII (FVIII), CD31 and CD34 were generally expressed in the MVECs. The fluorescence intensity of FVIII was higher after magnetic separation than before, while those of CD31 and CD34 didn't have significant difference. In conclusion, highly pure MVECs were isolated from rat intestinal mucosae using magnetic beads coated with anti-CD31 antibodies, and magnetic separation may influence the expression of FVIII.

Advanced organic recovery from municipal wastewater with an enhanced magnetic separation (EMS) system: Pilot-scale verification

The up-concentration process has been demonstrated as an attractive approach to carbon-neutral wastewater treatment. Innovation in the separation processes can help eliminate the current heavy dependence on gravity, and credible pilot-scale verification is crucial for application promotion. We hereby proposed a pilot-scale enhanced magnetic separation (EMS) system as an up-concentration step to maximize energy recovery from municipal wastewater. The design of EMS was based on the hypothesis that magnetic-driven separation could be a breakthrough in separation speed, and adsorption could further enhance the separation efficiency by capturing soluble substances. Jar tests confirmed the feasibility of activated carbon adsorption, which could also roughen the surface of aggregates. Further, over one-year operation of a 300 m3/d EMS equipment provided optimum operation strategies and evidence of system effectiveness. More than 80% of particulate organics and 60% of soluble organics were removed within 10 min at an energy consumption of only 0.036 kWh/m3. The characteristics of sludge were clarified in terms of organic concentration, extracellular polymeric substances composition, and micro-community analysis. The anaerobic experiments further demonstrated the potential value of the concentrated products. Surprisingly, the developed EMS system exhibited significant advantages in time consumption and space occupation, with competitive operating cost and energy consumption. Overall, the results of this study posed the EMS process for up-concentration as a potential approach to organics recovery from municipal wastewater.

Nucleic Acid-Based Nanobiosensor (NAB) Used for Salmonella Detection in Foods: A Systematic Review

Salmonella bacteria is a foodborne pathogen found mainly in food products causing severe symptoms in the individual, such as diarrhea, fever, and abdominal cramps after consuming the infected food, which can be fatal in some severe cases. Rapid and selective methods to detect Salmonella bacteria can prevent outbreaks when ingesting contaminated food. Nanobiosensors are a highly sensitive, simple, faster, and lower cost method for the rapid detection of Salmonella, an alternative to conventional enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) techniques. This study systematically searched and analyzed literature data related to nucleic acid-based nanobiosensors (NABs) with nanomaterials to detect Salmonella in food, retrieved from three databases, published between 2010 and 2021. We extracted data and critically analyzed the effect of nanomaterial functionalized with aptamer or DNA at the limit of detection (LOD). Among the nanomaterials, gold nanoparticles (AuNPs) were the most used nanomaterial in studies due to their unique optical properties of the metal, followed by magnetic nanoparticles (MNPs) of Fe3O4, copper nanoparticles (CuNPs), and also hybrid nanomaterials multiwalled carbon nanotubes (c-MWCNT/AuNP), QD/UCNP-MB (quantum dotes upconverting nanoparticle of magnetic beads), and cadmium telluride quantum dots (CdTe QDs@MNPs) showed excellent LOD values. The transducers used for detection also varied from electrochemical, fluorescent, surface-enhanced Raman spectroscopy (SERS), RAMAN spectroscopy, and mainly colorimetric due to the possibility of visualizing the detection result with the naked eye. Furthermore, we show the magnetic separation system capable of detecting the target amplification of the genetic material. Finally, we present perspectives, future research, and opportunities to use point-of-care (POC) diagnostic devices as a faster and lower cost approach for detecting Salmonella in food as they prove to be viable for resource-constrained environments such as field-based or economically limited conditions.