Magnetic nanostructures for emerging biomedical applications

Peixoto, L.; Magalhães, Ricardo; Navas, D.; Moraes, Suellen Silveira; Redondo, Carolina; Morales, R.; Araújo, João P.; Sousa, C. T.

doi:10.1063/1.5121702

Cited by 59 publications

(46 citation statements)

References 191 publications

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“…The room-temperature hysteresis loop, reported in Figure 2B, demonstrates that the NDs present a typical vortex-state configuration at the magnetic remanence (Guimarães, 2009;Peixoto et al, 2020), with expulsion and nucleation fields when saturation or remanence are approached, respectively. The measured loop is the average of the contribution to magnetic moment of individual NDs, whose orientation with respect to the applied field is random, as they are dispersed in water (Tiberto et al, 2015).…”

Section: Resultsmentioning

confidence: 92%

“…In the last decade, NPs consisting of soft ferromagnetic alloys, such as FeNi, FePd, received much interest for their ability to stabilize a controllable magnetic vortex domain configuration when they are prepared in discoidal shape (Rozhkova et al, 2009;Kim et al, 2010;Leulmi et al, 2015;Tiberto et al, 2015Tiberto et al, , 2016Barrera et al, 2016) within a proper selected range of diameters and aspect ratio (Tiberto et al, 2016;Peixoto et al, 2020). This magnetic vortex configuration induces peculiar magnetic properties to the discoidal NPs, not present in the more conventional iron oxide-based spherical ones, such zero remanence, high magnetic saturation and susceptibility, as well as the presence of a hysteresis at high field (Kim et al, 2010;Tiberto et al, 2015;Barrera et al, 2016).…”

Section: Introductionmentioning

confidence: 99%

“…Therefore, the development of growth and lithographic procedures in order to obtain magnetic NPs with discoidal shape allows to combine these unique magnetic properties with the abovementioned benefits in biomedicine (i-iii), making this kind of magnetic NPs suitable candidates to develop advanced magnetic-based treatments for cancer therapies such as drug delivery assisted by magnetic gradient field, magnetomechanical cell destruction, and magnetic hyperthermia (Rozhkova et al, 2009;Kim et al, 2010;Leulmi et al, 2015;Ferrero et al, 2019;Peixoto et al, 2020).…”

Section: Introductionmentioning

confidence: 99%

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Au-Coated Ni80Fe20 Submicron Magnetic Nanodisks: Interactions With Tumor Cells

Divieto

Barrera

Celegato

et al. 2020

Front. Nanotechnol.

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Effective interaction and accumulation of nanoparticles (NPs) within tumor cells is crucial for NP-assisted diagnostic and therapeutic biomedical applications. In this context, the shape and size features of NPs can severely influence the strength of adhesion between NPs and cell and the NP internalization mechanisms. This study proved the ability of the PT45 and A549 tumor cells to uptake and retain magnetic Au-coated Ni 80 Fe 20 nanodisks (NDs) prepared by means of a bottom-up self-assembling nanolithography technique assisted by polystyrene nanospheres. The chosen geometrical parameters, i.e., diameter (≈650 nm) and thickness (≈30 nm), give rise to magnetic domain patterns arranged in vortex state at the magnetic remanence. PT45 and A549 cell lines were cultured in the presence of different concentrations of Au-coated Ni 80 Fe 20 nanodisks, and their biocompatibility was evaluated by viability and proliferation tests. Electron microscopy techniques and a combined CARS (Coherent Anti-stokes Raman Scattering) and TPL (two-photon photoluminescence) microscopy allow localizing and distinguishing the NDs within or attached to the tumor cells, without any labeling. A quantitative measurement of ND amount retained within tumor cells as a function of ND concentrations was performed by the Instrumental Neutron Activation Analysis (INAA) characterization technique.

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Section: Resultsmentioning

confidence: 92%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Au-Coated Ni80Fe20 Submicron Magnetic Nanodisks: Interactions With Tumor Cells

Divieto

Barrera

Celegato

et al. 2020

Front. Nanotechnol.

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“…The unusual properties of nanowires (NWs) arise from their high-density of electronic states, high surface to volume ratio and high aspect ratio. In comparison with other low-dimensional systems, NWs have two quantum-confined and one unconfined direction that make it possible to tune their magnetic properties, namely, the Curie temperature, coercivity on both axes, orientation of the magnetic easy axis, saturation field and magnetization and remanence magnetization [ 7 ]. Moreover, in NWs with multiple segments along their length, an antiferromagnetic coupling can be induced by controlling the separation between the magnetic layers [ 74 ].…”

Section: Magnetic Propertiesmentioning

confidence: 99%

“…This may be attributed to the fact that they are size-restricted by the superparamagnetic regime, which limits the magnetic moment of each particle, and, through simulations, it was verified that the optimal dimensions of particles for MRI contrast agents surpass such superparamagnetic threshold [ 6 ]. Among the various nanomaterials that can be found in the literature with different shapes and compositions, magnetic nanostructures (MNS), and in particular, nanodiscs and nanowires, are promising alternatives to SPIONs due to their larger magnetic moments that are not restrained by the superparamagnetic regime [ 7 ]. Also, MNS are a promising system for theragnostics, since they can be used as contrast agents and, at the same time, generate localized heating inside the body with the use of an external alternating current (AC) magnetic field, or be used for controlled drug delivery, photodynamic therapy and neutron capture therapy [ 8 , 9 ].…”

Section: Introductionmentioning

confidence: 99%

Magnetic Nanomaterials as Contrast Agents for MRI

et al. 2020

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Magnetic Resonance Imaging (MRI) is a powerful, noninvasive and nondestructive technique, capable of providing three-dimensional (3D) images of living organisms. The use of magnetic contrast agents has allowed clinical researchers and analysts to significantly increase the sensitivity and specificity of MRI, since these agents change the intrinsic properties of the tissues within a living organism, increasing the information present in the images. Advances in nanotechnology and materials science, as well as the research of new magnetic effects, have been the driving forces that are propelling forward the use of magnetic nanostructures as promising alternatives to commercial contrast agents used in MRI. This review discusses the principles associated with the use of contrast agents in MRI, as well as the most recent reports focused on nanostructured contrast agents. The potential applications of gadolinium- (Gd) and manganese- (Mn) based nanomaterials and iron oxide nanoparticles in this imaging technique are discussed as well, from their magnetic behavior to the commonly used materials and nanoarchitectures. Additionally, recent efforts to develop new types of contrast agents based on synthetic antiferromagnetic and high aspect ratio nanostructures are also addressed. Furthermore, the application of these materials in theragnosis, either as contrast agents and controlled drug release systems, contrast agents and thermal therapy materials or contrast agents and radiosensitizers, is also presented.

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Wireless Force‐Inducing Neuronal Stimulation Mediated by High Magnetic Moment Microdiscs

Collier

Muzzio

Guntnur

et al. 2021

Adv Healthcare Materials

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Noninvasive manipulation of cell signaling is critical in basic neuroscience research and in developing therapies for neurological disorders and psychiatric conditions. Here, the wireless force-induced stimulation of primary neuronal circuits through mechanotransduction mediated by magnetic microdiscs (MMDs) under applied low-intensity and low-frequency alternating magnetic fields (AMFs), is described. MMDs are fabricated by top-down lithography techniques that allow for cost-effective mass production of biocompatible MMDs with high saturation and zero magnetic magnetic moment at remanence. MMDs are utilized as transducers of AMFs into mechanical forces. When MMDs are exposed to primary rat neuronal circuits, their magneto-mechanical actuation triggers the response of specific mechanosensitive ion channels expressed on the cell membranes activating ≈50% of hippocampal and ≈90% of cortical neurons subjected to the treatment. Mechanotransduction is confirmed by the inhibition of mechanosensitive transmembrane channels with Gd 3+ . Mechanotransduction mediated by MMDs cause no cytotoxic effect to neuronal cultures. This technology fulfills the requirements of cell-type specificity and weak magnetic fields, two limiting factors in the development of noninvasive neuromodulation therapies and clinical equipment design. Moreover, high efficiency and long-lasting stimulations are successfully achieved. This research represents a fundamental step forward for magneto-mechanical control of neural activity using disc-shaped micromaterials with tailored magnetic properties.

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Magnetic nanostructures for emerging biomedical applications

Cited by 59 publications

References 191 publications

Au-Coated Ni80Fe20 Submicron Magnetic Nanodisks: Interactions With Tumor Cells

Au-Coated Ni80Fe20 Submicron Magnetic Nanodisks: Interactions With Tumor Cells

Magnetic Nanomaterials as Contrast Agents for MRI

Wireless Force‐Inducing Neuronal Stimulation Mediated by High Magnetic Moment Microdiscs

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