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1.
Anal Chim Acta ; 1242: 340794, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36657889

RESUMO

In this study, an assay for detection of the cancer biomarker Thomsen-nouvelle (Tn) antigen on the ELISA plates format was designed and developed. The effects of size and the interfacial density of the negative charge of magnetic beads (MBs) on the specific sensitivity of the bioaffinity interaction were studied. In particular, glyconanoconjugate, i.e. glycan Tn antigen conjugated to bovine serum albumin (BSA) was covalently immobilised on MBs for the bioaffinity detection of anti-Tn antibodies as cancer biomarkers. Six different MBs were used in the study, i.e. carboxy-modified MBs of 250 nm, 500 nm, 1000 nm and 2800 nm and epoxy-modified MBs of 2800 nm and 4500 nm. In order to evaluate which MBs are the best suited for detection of the analyte anti-Tn antibodies, sensitivities of detection (slopes from calibration curves) were calculated. Next, specific sensitivities were calculated for each type of MBs as a ratio of sensitivity of detection to the mass of MBs. From zeta potential ζ for each type of MBs, the interfacial charge density on MBs was calculated, expressed as the density of zeta potential ζd (ratio of zeta potential to surface area of MBs, i.e. ζd = Î¶/A). Then, we evaluated the effect of size and ζd on the specific sensitivity of detection of anti-Tn antibodies in order to understand the immobilisation process on nanoscale. We also identified an optimal value of ζd on MBs; this was essential to achieve highly sensitive detection of the analyte, which made it possible to attain limit of detection (LOD) of (0.31 ± 0.01) ng mL-1 or (2.10 ± 0.04) pM for analyte detection. In addition, the optimal assay configuration was highly selective and enabled reliable detection of the analyte in human serum with a recovery index in the range of 102-104%.


Assuntos
Antígenos Glicosídicos Associados a Tumores , Magnetismo , Nanoconjugados , Humanos , Fenômenos Magnéticos , Soroalbumina Bovina , Nanoconjugados/química , Antígenos Glicosídicos Associados a Tumores/análise
2.
Cells ; 12(2)2023 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-36672273

RESUMO

Magnetic force and gravity are two fundamental forces affecting all living organisms, including bacteria. On Earth, experimentally created magnetic force can be used to counterbalance gravity and place living organisms in conditions of magnetic levitation. Under conditions of microgravity, magnetic force becomes the only force that moves bacteria, providing an acceleration towards areas of the lowest magnetic field and locking cells in this area. In this review, we consider basic principles and experimental systems used to create a magnetic force strong enough to balance gravity. Further, we describe how magnetic levitation is applied in on-Earth microbiological studies. Next, we consider bacterial behavior under combined conditions of microgravity and magnetic force onboard a spacecraft. At last, we discuss restrictions on applications of magnetic force in microbiological studies and the impact of these restrictions on biotechnological applications under space and on-Earth conditions.


Assuntos
Magnetismo , Ausência de Peso , Fenômenos Magnéticos
3.
Sci Rep ; 13(1): 414, 2023 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-36624156

RESUMO

Rare birds known as "accidentals" or "vagrants" have long captivated birdwatchers and puzzled biologists, but the drivers of these rare occurrences remain elusive. Errors in orientation or navigation are considered one potential driver: migratory birds use the Earth's magnetic field-sensed using specialized magnetoreceptor structures-to traverse long distances over often unfamiliar terrain. Disruption to these magnetoreceptors or to the magnetic field itself could potentially cause errors leading to vagrancy. Using data from 2 million captures of 152 landbird species in North America over 60 years, we demonstrate a strong association between disruption to the Earth's magnetic field and avian vagrancy during fall migration. Furthermore, we find that increased solar activity-a disruptor of the avian magnetoreceptor-generally counteracts this effect, potentially mitigating misorientation by disabling the ability for birds to use the magnetic field to orient. Our results link a hypothesized cause of misorientation to the phenomenon of avian vagrancy, further demonstrating the importance of magnetoreception among the orientation mechanisms of migratory birds. Geomagnetic disturbance may have important downstream ecological consequences, as vagrants may experience increased mortality rates or facilitate range expansions of avian populations and the organisms they disperse.


Assuntos
Migração Animal , Orientação , Animais , Magnetismo , Aves , Campos Magnéticos
4.
Sensors (Basel) ; 23(2)2023 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-36679496

RESUMO

In order to overcome the shortcomings of the traditional magnetic absolute linear displacement sensors in which cables affect the flexibility and measurement range in linear motor transmission systems, this paper proposes a novel cable-free moving magnetic grid-type long-range absolute displacement sensor. The sensor consists of a magnetic grid and a signal acquisition board. The magnetic grid is a moving component that contains two rows of permanent magnet arrays, one for relative displacement measurement and the other for the displacement interval code. The signal acquisition board is a fixed component that uses n groups of two-row Hall sensor arrays for continuous absolute displacement measurement. The principle of the sensor using the 2D magnetic field signal for the relative displacement measurement is analyzed, and a measurement method based on Hall sensor arrays for coding and absolute displacement detection over n cycles is proposed. Finally, a sensor prototype is fabricated and the experiments are performed. The experimental results show that the measurement resolution of the sensor is 5 µm, and the measurement accuracy is ±14.8 µm within the measurement range of 0-98.3 mm. The proposed sensor can realize continuous absolute displacement measurement over multiple cycles without cable binding.


Assuntos
Sistemas Computacionais , Campos Magnéticos , Magnetismo
5.
Sensors (Basel) ; 23(2)2023 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-36679774

RESUMO

Multi-objective (MO) optimization is a developing technique for increasing closed-loop performance and robustness. However, its applications to control engineering mostly concern first or second order approximation models. This article proposes a novel MO algorithm, suitable for the design and control of mechanical systems, which does not require any order reduction techniques. The controller parameters are determined directly from a special type of rapid analysis of simulated transient responses. The case study presented in this article consists of a magnetic levitation system. Certain difficulties such as the nonlinearity identification of the magnetic force and duo magnetic field sensor scheme were addressed. To point out the advantages of using the developed approach, the simulations as well as the experiments performed with the help of the created algorithm were compared to those made with common MO algorithms.


Assuntos
Algoritmos , Magnetismo , Simulação por Computador , Campos Magnéticos , Engenharia
6.
Sensors (Basel) ; 23(2)2023 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-36679836

RESUMO

In this study, we design a highly efficient plasma source using a magnetic mirror trap with two opposing permanent magnets for a miniature high-efficiency ion pump. First, we simulated the distribution of the magnetic field line formed by the proposed magnetic mirror configuration. By optimizing the distance between two opposing permanent magnets and size of these magnets, a magnetic mirror ratio value of 27 could be obtained, which is an electron confinement efficiency of over 90%. We also conducted an experiment on a high-efficiency discharge plasma source for a miniature ion pump using an optimized magnetic circuit. As a result, we revealed that the proposed magnetic circuit has a pronounced effect on plasma generation, particularly in the high-vacuum region.


Assuntos
Magnetismo , Imãs , Campos Magnéticos , Vácuo , Elétrons
7.
Inorg Chem ; 62(3): 1075-1085, 2023 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-36625763

RESUMO

Herein, hexaazamacrocyclic ligand LN6 was employed to construct a series of photochromic rare-earth complexes, [Ln(LN6)(NO3)2](BPh4) [1-Ln, Ln = Dy, Tb, Eu, Gd, Y; LN6 = (3E,5E,10E,12E)-3,6,10,13-tetraaza-1,8(2,6)-dipyridinacyclotetradecaphane-3,5,10,12-tetraene]. The behavior of photogenerated radicals of hexaazamacrocyclic ligands was revealed for the first time. Upon 365 nm light irradiation, complexes 1-Ln exhibit photochromic behavior induced by photogenerated radicals according to EPR and UV-vis analyses. Static and dynamic magnetic studies of 1-Dy and irradiated product 1-Dy* indicate weak ferromagnetic interactions among DyIII ions and photogenerated LN6 radicals, as well as slow magnetization relaxation behavior under a 2 kOe applied field. Further fitting analyses show that the magnetization relaxation in 1-Dy* is markedly different from 1-Dy. Time-dependent fluorescence measurements reveal the characteristic luminescence quenching dynamics of lanthanide in the photochromic process. Especially for irradiated product 1-Eu*, the luminescence is almost completely quenched within 5 min with a quenching efficiency of 98.4%. The results reported here provide a prospect for the design of radical-induced photochromic lanthanide single-molecule magnets and will promote the further development of multiresponsive photomagnetic materials.


Assuntos
Elementos da Série dos Lantanídeos , Luminescência , Magnetismo , Imãs , Fluorescência , Ligantes
8.
Anal Chim Acta ; 1239: 340615, 2023 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-36628698

RESUMO

A novel porphyrin-based magnetic covalent organic framework (PCOF) was first reported by using a facile synthetic procedure. The Fe3O4@NH2@PCOF nanospheres were utilized to effectively extract personal care products in a wide polarity range (log Kow values from 1.96 to 7.60). The successful magnetic solid-phase extraction (MSPE) of target analytes could be ascribed to the sufficient oxygen-, nitrogen- and phenyl-containing functional groups of the COF layer, which are demonstrated to be of good compatibility with pollutants exhibiting different polarities by using molecular dynamics simulations, independent gradient model analysis and various characterizations. The MSPE extraction efficiency was enhanced by optimizing key parameters. The findings indicated that the method had a wide linearity range (1-500 ng mL-1 for parabens and UV filters) and low detection limits (0.4-0.9 ng mL-1 for parabens and 0.2-0.6 ng mL-1 for UV filters). The accuracy was reflected by recoveries ranging from 74% to 114%. Satisfactory intra- and inter-day precisions from 3.0% to 9.8% and 0.5%-9.1% were obtained. Overall, the proposed MSPE-HPLC method is accurate and reliable for identifying parabens as well as UV filters in wastewater and swimming pool water. The potential of the method for evaluating human exposure risk was unfolded.


Assuntos
Estruturas Metalorgânicas , Porfirinas , Humanos , Parabenos/análise , Magnetismo/métodos , Extração em Fase Sólida/métodos , Cromatografia Líquida de Alta Pressão , Fenômenos Magnéticos , Limite de Detecção
9.
Nanotheranostics ; 7(1): 102-116, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36593801

RESUMO

Delivering therapies to deeply seated brain tumours (BT) is a major clinical challenge. Magnetic drug targeting (MDT) could overcome this by rapidly transporting magnetised drugs directly into BT. We have developed a magnetic device for application in murine BT models using an array of neodymium magnets with a combined strength of 0.7T. In a closed fluidic system, the magnetic device trapped magnetic nanoparticles (MNP) up to distances of 0.8cm. In mice, the magnetic device guided intravenously administered MNP (<50nm) from the circulation into the brain where they localised within mouse BT. Furthermore, MDT of magnetised Temozolomide (TMZmag+) significantly reduced tumour growth and extended mouse survival to 48 days compared to the other treatment groups. Using the same principles, we built a proof of principle scalable magnetic device for human use with a strength of 1.1T. This magnetic device demonstrated trapping of MNP undergoing flow at distances up to 5cm. MDT using our magnetic device provides an opportunity for targeted delivery of magnetised drugs to human BT.


Assuntos
Neoplasias Encefálicas , Sistemas de Liberação de Medicamentos , Humanos , Camundongos , Animais , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/patologia , Magnetismo , Temozolomida , Fenômenos Magnéticos
10.
Molecules ; 28(1)2023 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-36615607

RESUMO

The chemical immobilization of cobalt(II) ions in a silica aerogel matrix enabled the synthesis of the first representative example of aerogel-based single-ion magnets. For the synthesis of the lyogels, methyl-trimethoxysilane and N-3-(trimethoxysilyl)propyl ethylenediamine were co-hydrolyzed, then the ethylenediamine groups that were immobilized on the silica matrix enabled the subsequent binding of cobalt(II) ions. Lyogels with various amounts of ethylenediamine moieties (0.1-15 mol %) were soaked in isopropanol solutions of cobalt(II) nitrate and further supercritically dried in carbon dioxide to obtain aerogels with a specific surface area of 210-596 m2·g-1, an apparent density of 0.403-0.740 cm3·g-1 and a porosity of 60-78%. The actual cobalt content in the aerogels was 0.01-1.50 mmol per 1 g of SiO2, which could easily be tuned by the concentration of ethylenediamine moieties in the silica matrix. The introduction of cobalt(II) ions into the ethylenediamine-modified silica aerogel promoted the stability of the diamine moieties at the supercritical drying stage. The molecular prototype of the immobilized cobalt(II) complex, bearing one ethylenediamine ligand [Co(en)(MeCN)(NO3)2], was synthesized and structurally characterized. Using magnetometry in the DC mode, it was shown that cobalt(II)-modified silica aerogels exhibited slow magnetic relaxation in a nonzero field. A decrease in cobalt(II) concentration in aerogels from 1.5 mmol to 0.14 mmol per 1 g of SiO2 resulted in a weakening of inter-ion interactions; the magnetization reversal energy barrier likewise increased from 4 to 18 K.


Assuntos
Imãs , Dióxido de Silício , Dióxido de Silício/química , Cobalto/química , Magnetismo , Etilenodiaminas
11.
Biosens Bioelectron ; 222: 114745, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36502714

RESUMO

The process of developing an end-to-end model of a magneto-immunoassay is described, simulating the agglutination effect due to the specific binding of bacteria to paramagnetic particles. After establishing the properties of the dose-specific agglutination through direct imaging, a microfluidic assay was used to demonstrate changes in the magnetophoretic transport dynamics of agglutinated clusters via transient inductive magentometer measurements. End-to-end mathematical modelling is used to establish the physical processes underlying the assay. First, a modified form of Becker-Döring nucleation kinetic equations is used to establish a relationship between analyte dose and average cluster size. Next, Stokes flow equations are used to establish a relationship between cluster size and speed of motion within the fluid chamber. This predicts a cluster-size dynamic profile of concentration of PMPs versus time when the magnetic field is switched between the two actuated magnets. Finally, inductive modelling is carried out to predict the response of the magnetometer circuit in response to the dynamics of magnetic clusters. The predictions of this model are shown to agree well with the results of experiments, and to predict the shape of the dose-response curve.


Assuntos
Técnicas Biossensoriais , Modelos Teóricos , Magnetismo , Imãs , Movimento (Física)
12.
J Chromatogr A ; 1687: 463702, 2023 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-36508770

RESUMO

Recently, covalent organic frameworks (COFs) have been widely used to prepare magnetic adsorbents for food analysis due to their highly tunable porosity, large specific surface area, excellent chemical and thermal stability and large delocalised π-electron system. This review summarises the main types and preparation methods of magnetic COFs and their applications in food analysis for the detection of pesticide residues, veterinary drugs, endocrine-disrupting phenols and estrogens, plasticisers and other food contaminants. Furthermore, challenges and future outlook in the development of magnetic COFs for food analysis are discussed.


Assuntos
Estruturas Metalorgânicas , Estruturas Metalorgânicas/química , Análise de Alimentos , Magnetismo , Porosidade , Fenômenos Magnéticos
13.
ACS Appl Bio Mater ; 6(1): 191-202, 2023 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-36580633

RESUMO

In this study, we prepared various anionic magnetic adsorbents through the carboxyl functionalization of core/shell-structured Fe3O4/SiO2 (FS) particles by either succinic anhydride (FSC), low-molecular-weight (MW 1800) polyacrylic acid (PAA) (FSP1), or high-molecular-weight (MW 100,000) PAA (FSP2), and then, investigated the effect of the structure of adsorbents and operational parameters on their performance for the lysozyme separation. The type and size of functional molecules have significant effects on the surface concentration of functional carboxyl groups onto the adsorbent particles (increase in the order of FSP2 > FSP1 > FSC), and consequently on the adsorption efficiency (AE) (∼100, 98, and 62%, respectively) and adsorption capacity (AC) (∼1000, 980, and 621 mg·g-1, respectively) of the adsorbents. However, the loss of the antibacterial activity of separated lysozyme molecules due to the molecular conformational change increased in the order of FSP2 > FSP1 = FSC, as compared to the free lysozyme. The application of basic buffer solutions for the elution of adsorbed enzyme molecules resulted in more adverse effects on the enzyme activity. The obtained results recommend that FSP1 can be used as a suitable anionic adsorbent for the isolation of positively charged proteins, owing to its high adsorption capacity, excellent reusability, and structural stability, as well as the high purity, structural stability, and activity recovery of the isolated proteins.


Assuntos
Muramidase , Nanocompostos , Muramidase/química , Dióxido de Silício/química , Magnetismo , Nanocompostos/química , Fenômenos Magnéticos
14.
Waste Manag ; 156: 255-263, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36508909

RESUMO

A major industrial solid waste, iron tailings occupy a large area and pose long-term pollution risks. The pyrolysis gas of biomass was used as reducing agent to suspension magnetize and roast iron tailings to recover iron in this study. The process conditions, phase transformation and microstructure evolution of the iron tailings, pyrolysis gas production, and reaction regulations were investigated to explain the mechanism of iron recovery by suspension magnetization roasting (SMR) under the action of biomass pyrolysis gas. These studies were conducted using X-ray diffraction, scanning electron microscopy, vibrating sample magnetometer, thermo-gravimetric and differential scanning calorimetry, brunauer-emmett-teller specific surface area, and gas chromatography. The results showed that, after the grinding-magnetic separation process, the iron recovery rate was 93.32 %; the iron grade of the iron concentrate was 61.50 %. The optimal process conditions were determined as follows: fast pyrolysis temperature of 600 °C, SMR temperature of 700 °C, biomass dosage of 10 %, and SMR time of 4-5 min. The formation of Fe3O4 from the surface to the interior of the particles during the reduction process, and formation of pores and cracks led to an increase in the specific surface area. The SMR temperature not only improved the heat and mass transfer effect in the reduction process but also generated more CO and H2 through the reverse reaction of methanation, which work together to increase the saturation magnetisation of the unit sample. This method can be used to efficiently recover high quality iron from refractory iron ores.


Assuntos
Ferro , Pirólise , Biomassa , Ferro/química , Termogravimetria , Magnetismo , Resíduos Industriais/análise
15.
Nano Lett ; 23(1): 58-65, 2023 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-36584282

RESUMO

Immunoassays exploiting magnetization dynamics of magnetic nanoparticles are highly promising for mix-and-measure, quantitative, and point-of-care diagnostics. However, how single-core magnetic nanoparticles can be employed to reduce particle concentration and concomitantly maximize assay sensitivity is not fully understood. Here, we design monodisperse Néel and Brownian relaxing magnetic nanocubes (MNCs) of different sizes and compositions. We provide insights into how to decouple physical properties of these MNCs to achieve ultrahigh sensitivity. We find that tricomponent-based Zn0.06Co0.80Fe2.14O4 particles, with out-of-phase to initial magnetic susceptibility χ″/χ0 ratio of 0.47 out of 0.50 for magnetically blocked ideal particles, show the ultrahigh magnetic sensitivity by providing a rich magnetic particle spectroscopy (MPS) harmonics spectrum despite bearing lower saturation magnetization than dicomponent Zn0.1Fe2.9O4 having high saturation magnetization. The Zn0.06Co0.80Fe2.14O4 MNCs, coated with catechol-based poly(ethylene glycol) ligands, measured by our benchtop MPS show 3 orders of magnitude better particle LOD than that of commercial nanoparticles of comparable size.


Assuntos
Nanopartículas de Magnetita , Nanopartículas , Nanopartículas de Magnetita/química , Magnetismo , Campos Magnéticos , Fenômenos Físicos , Análise Espectral , Nanopartículas/química
16.
Nat Commun ; 13(1): 7626, 2022 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-36494346

RESUMO

Three decades of research in molecular nanomagnets have raised their magnetic memories from liquid helium to liquid nitrogen temperature thanks to a wise choice of the magnetic ion and coordination environment. Still, serendipity and chemical intuition played a main role. In order to establish a powerful framework for statistically driven chemical design, here we collected chemical and physical data for lanthanide-based nanomagnets, catalogued over 1400 published experiments, developed an interactive dashboard (SIMDAVIS) to visualise the dataset, and applied inferential statistical analysis. Our analysis shows that the Arrhenius energy barrier correlates unexpectedly well with the magnetic memory. Furthermore, as both Orbach and Raman processes can be affected by vibronic coupling, chemical design of the coordination scheme may be used to reduce the relaxation rates. Indeed, only bis-phthalocyaninato sandwiches and metallocenes, with rigid ligands, consistently present magnetic memory up to high temperature. Analysing magnetostructural correlations, we offer promising strategies for improvement, in particular for the preparation of pentagonal bipyramids, where even softer complexes are protected against molecular vibrations.


Assuntos
Elementos da Série dos Lantanídeos , Elementos da Série dos Lantanídeos/química , Ligantes , Temperatura , Magnetismo
17.
Nat Commun ; 13(1): 7919, 2022 12 23.
Artigo em Inglês | MEDLINE | ID: mdl-36564394

RESUMO

Miniature magnetic soft machines could significantly impact minimally invasive robotics and biomedical applications. However, most soft machines are limited to solid magnetic materials, whereas further progress also relies on fluidic constructs obtained by reconfiguring liquid magnetic materials, such as ferrofluid. Here we show how harnessing the wettability of ferrofluids allows for controlled reconfigurability and the ability to create versatile soft machines. The ferrofluid droplet exhibits multimodal motions, and a single droplet can be controlled to split into multiple sub-droplets and then re-fuse back on demand. The soft droplet machine can negotiate changing terrains in unstructured environments. In addition, the ferrofluid droplets can be configured as a liquid capsule, enabling cargo delivery; a wireless omnidirectional liquid cilia matrix capable of pumping biofluids; and a wireless liquid skin, allowing multiple types of miniature soft machine construction. This work improves small magnetic soft machines' achievable complexity and boosts their future biomedical applications capabilities.


Assuntos
Robótica , Molhabilidade , Movimento (Física) , Magnetismo , Cílios
18.
Sensors (Basel) ; 22(24)2022 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-36560230

RESUMO

We present a single-beam all-optical two-channel magnetic sensor scheme developed for biological applications such as non-zero-field magnetoencephalography and magnetocardiography. The pumping, excitation and detection of magnetic resonance in two cells are performed using a single laser beam with time-modulated linear polarization: the linear polarization of the beam switches to orthogonal every half-cycle of the Larmor frequency. Light with such characteristics can be transmitted over a single-mode polarization-maintaining fiber without any loss in the quality of the polarization characteristics. We also present an algorithm for calculating optical elements in a sensor scheme, the results of measuring the parametric dependences of magnetic resonance in cells, and the results of direct testing of a sensor in a magnetic shield. We demonstrate sensitivity at the level of 20 fT/√Hz in one sensor channel in the frequency range of 80-200 Hz.


Assuntos
Magnetocardiografia , Dispositivos Ópticos , Magnetoencefalografia , Magnetismo , Luz
19.
J Nanobiotechnology ; 20(1): 547, 2022 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-36587223

RESUMO

Cancer immunotherapy has shown promising therapeutic results in the clinic, albeit only in a limited number of cancer types, and its efficacy remains less than satisfactory. Nanoparticle-based approaches have been shown to increase the response to immunotherapies to address this limitation. In particular, magnetic nanoparticles (MNPs) as a powerful manipulator are an appealing option for comprehensively regulating the immune system in vivo due to their unique magnetically responsive properties and high biocompatibility. This review focuses on assessing the potential applications of MNPs in enhancing tumor accumulation of immunotherapeutic agents and immunogenicity, improving immune cell infiltration, and creating an immunotherapy-sensitive environment. We summarize recent progress in the application of MNP-based manipulators to augment the efficacy of immunotherapy, by MNPs and their multiple magnetically responsive effects under different types of external magnetic field. Furthermore, we highlight the mechanisms underlying the promotion of antitumor immunity, including magnetically actuated delivery and controlled release of immunotherapeutic agents, tracking and visualization of immune response in real time, and magnetic regulation of innate/adaptive immune cells. Finally, we consider perspectives and challenges in MNP-based immunotherapy.


Assuntos
Nanopartículas , Neoplasias , Humanos , Imunoterapia , Neoplasias/tratamento farmacológico , Magnetismo , Campos Magnéticos , Nanopartículas/uso terapêutico
20.
Sci Rep ; 12(1): 20767, 2022 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-36513660

RESUMO

Programmable matter can change its shape, stiffness or other physical properties upon command. Previous work has shown contactless optically controlled matter or magnetic actuation, but the former is limited in strength and the latter in spatial resolution. Here, we show an unprecedented level of control combining light patterns and magnetic fields. A mixture of thermoplastic and ferromagnetic powder is heated up at specific locations that become malleable and are attracted by magnetic fields. These heated areas solidify on cool down, and the process can be repeated. We show complex control of 3D slabs, 2D sheets, and 1D filaments with applications in tactile displays and object manipulation. Due to the low transition temperature and the possibility of using microwave heating, the compound can be manipulated in air, water, or inside biological tissue having the potential to revolutionize biomedical devices, robotics or display technologies.


Assuntos
Magnetismo , Robótica , Tato , Água , Campos Magnéticos
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