Hybrid Layer Thickness and Resin Tags Penetration of two Universal Adhesives Incorporated with Ascorbic Acid Coated Superparamagnetic Nanoparticles Subjected to External Magnetic Field

2020 ◽  
Vol 12 (sp1) ◽  
Keyword(s):  
Magnetic Field ◽  
Ascorbic Acid ◽  
External Magnetic Field ◽  
Layer Thickness ◽  
Superparamagnetic Nanoparticles ◽  
Hybrid Layer ◽  
Universal Adhesives

scholarly journals Synthesis of Poly-Sodium-Acrylate (PSA)-Coated Magnetic Nanoparticles for Use in Forward Osmosis Draw Solutions

Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1238 ◽  
Author(s):  
Irena Ban ◽  
Sabina Markuš ◽  
Sašo Gyergyek ◽  
Miha Drofenik ◽  
Jasmina Korenak ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Nanoparticles ◽  
External Magnetic Field ◽  
Osmotic Pressure ◽  
Forward Osmosis ◽  
Superparamagnetic Nanoparticles ◽  
Molar Ratio ◽  
Sodium Acrylate ◽  
Molar Ratios ◽  
Magnetite Phase

The synthesis of magnetic nanoparticles (MNPs) coated with hydrophilic poly-sodium-acrylate (PSA) ligands was studied to assess PSA-MNP complexes as draw solution (DS) solutes in forward osmosis (FO). For MNP-based DS, the surface modification and the size of the MNPs are two crucial factors to achieve a high osmolality. Superparamagnetic nanoparticles (NP) with functional groups attached may represent the ideal DS where chemical modifications of the NPs can be used in optimizing the DS osmolality and the magnetic properties allows for efficient recovery (DS re-concentration) using an external magnetic field. In this study MNPs with diameters of 4 nm have been prepared by controlled chemical co-precipitation of magnetite phase from aqueous solutions containing suitable salts of Fe2+ and Fe3+ under inert atmosphere and a pure magnetite phase could be verified by X-ray diffraction. Magnetic colloid suspensions containing PSA-coated MNPs with three different molar ratios of PSA:MNP = 1:1, 1:2 and 1:3 were prepared and assessed in terms of osmotic pressure, aggregation propensity and magnetization. Fourier Transform Infrared Spectroscopy (FTIR) confirmed the presence of PSA on coated MNPs and pristine PSA-MNPs with a molar ratio PSA:MNP = 1:1 exhibited an osmotic pressure of 30 bar. Molar ratios of PSA:MNP = 1:2 and 1:3 lead to the formation of less stabile magnetic colloid solutions, which led to the formation of aggregates with larger average hydrodynamic sizes and modest osmotic pressures (5.5 bar and 0.2 bar, respectively). After purification with ultrafiltration, the 1:1 nanoparticles exhibited an osmotic pressure of 9 bar with no aggregation and a sufficient magnetization of 25 emu/g to allow for DS regeneration using an external magnetic field. However, it was observed that the amount of PSA molecules attached to the MNPs decreased during DS recycling steps, leaving only strong chelate-bonded core-shell PSA as coating on the MNPs. This demonstrates the crucial role of MNP coating robustness in designing an efficient MNP-based DS for FO.

Epithelial internalization of superparamagnetic nanoparticles and response to external magnetic field

Biomaterials ◽  
2005 ◽  
Vol 26 (14) ◽  
pp. 2061-2072 ◽  
Author(s):  
Dormer Kenneth ◽  
Seeney Charles ◽  
Lewelling Kevin ◽  
Lian Guoda ◽  
Gibson Donald ◽  
...  
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Superparamagnetic Nanoparticles

Anisotropic magnetite nanoclusters with enhanced magnetization as an efficient ferrofluid in mass transfer and liquid hyperthermia

2019 ◽  
Vol 43 (21) ◽  
pp. 8044-8051 ◽  
Author(s):  
Alireza Mouraki ◽  
Zeinab Alinejad ◽  
Samira Sanjabi ◽  
Ali Reza Mahdavian
Keyword(s):  
Magnetic Field ◽  
Mass Transfer ◽  
External Magnetic Field ◽  
Superparamagnetic Nanoparticles ◽  
Stable Dispersion ◽  
Heat Build Up

A stable dispersion of anisotropic superparamagnetic nanoparticles was introduced for efficient heat build-up and mass transfer under an external magnetic field.

scholarly journals Intracellular Delivery of siRNA by Polycationic Superparamagnetic Nanoparticles

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Betzaida Castillo ◽  
Lev Bromberg ◽  
Xaira López ◽  
Valerie Badillo ◽  
Jose A. González Feliciano ◽  
...  
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Cell Lines ◽  
Transfection Efficiency ◽  
Membrane Damage ◽  
Superparamagnetic Iron Oxide ◽  
Superparamagnetic Nanoparticles ◽  
Sirna Transfection ◽  
Hela Cell Lines ◽  
Polycationic Polymers

The siRNA transfection efficiency of nanoparticles (NPs), composed of a superparamagnetic iron oxide core modified with polycationic polymers (poly(hexamethylene biguanide) or branched polyethyleneimine), were studied in CHO-K1 and HeLa cell lines. Both NPs demonstrated to be good siRNA transfection vehicles, but unmodified branched polyethyleneimine (25 kD) was superior on both cell lines. However, application of an external magnetic field during transfection (magnetofection) increased the efficiency of the superparamagnetic NPs. Furthermore, our results reveal that these NPs are less toxic towards CHO-K1 cell lines than the unmodified polycationic-branched polyethyleneimine (PEI). In general, the external magnetic field did not alter the cell’s viability nor it disrupted the cell membranes, except for the poly(hexamethylene biguanide)-modified NP, where it was observed that in CHO-K1 cells application of the external magnetic field promoted membrane damage. This paper presents new polycationic superparamagnetic NPs as promising transfection vehicles for siRNA and demonstrates the advantages of magnetofection.

scholarly journals Reversible rearrangement of magnetic nanoparticles in solution studied using time-resolved SAXS method

2019 ◽  
Vol 26 (4) ◽  
pp. 1294-1301
Author(s):  
Lanqing Huang ◽  
Jingeng Mai ◽  
Qihui Zhu ◽  
Zhen Guo ◽  
Siying Qin ◽  
...  
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Magnetic Fields ◽  
Magnetic Beads ◽  
Permanent Magnets ◽  
Superparamagnetic Nanoparticles ◽  
Shanghai Synchrotron Radiation Facility ◽  
Time Resolved ◽  
X Ray ◽  
Quantitative Measurements

Superparamagnetic nanoparticles have broad applications in biology and medicines. Quantitative measurements of magnetic beads in solution are essential in gaining comprehensive understanding of their dynamics and developing applications. Here, using synchrotron X-ray sources combined with well controlled magnetic fields, the results from small-angle X-ray scattering (SAXS) experiments on superparamagnetic particles in solution under the influence of external magnetic fields are reported. The particles mostly remain in monodispersed states and the linear aggregates tend to be aligned with the external magnetic field. After removing the magnetic fields, the superparamagnetic nanoparticles quickly recover to their original states indicating high reversibility of the rearrangement under the control of a magnetic field. The external magnetic field instrument composed of paired permanent magnets is integrated into the SAXS beamline at the Shanghai Synchrotron Radiation Facility providing a platform for studying time-resolved dynamics induced by magnetic fields.

scholarly journals ULTRASOUND-ASSISTED MAGNETIC NANOPARTICLE-BASED GENE DELIVERY

2020 ◽  
Author(s):  
Wei Zhang ◽  
Gaser N. Abdelrasoul ◽  
Oleksandra Savchenko ◽  
Abdalla Abdrabou ◽  
Zhixiang Wang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Gene Delivery ◽  
Transfection Efficiency ◽  
Genetic Material ◽  
Positive Control ◽  
Superparamagnetic Nanoparticles ◽  
Cell Permeability ◽  
Hek 293 ◽  
Delivery Technique

AbstractLow-intensity pulsed ultrasound (LIPUS), a special type of ultrasonic stimulation, is attracting a lot of attention for both clinical and scientific research. In this paper, we report a concept of a new method using magnetic nanoparticles (MNPs) for LIPUS-assisted gene delivery. The MNPs are iron oxide superparamagnetic nanoparticles, coated with polyethyleneimine (PEI), which introduces a high positive surface charge, favorable for the binding of genetic material. Due to the paramagnetic properties of the MNPs, the application of an external magnetic field increases transfection efficiency; meanwhile, LIPUS stimulation enhances cell permeability. We found out that stimulation at the intensity of 30 mW/cm2 for 10 minutes yields optimal results with a minimal adverse effect on the cells. Combining the effect of the external magnetic field and LIPUS, the genetic material (GFP or Cherry Red plasmid in our case) can enter the cells. The flow cytometry results showed that by using just a magnetic field to direct the genetic material, the transfection efficiency of HEK 293 cells that were treated with our MNPs was 56.1%. Coupled with LIPUS stimulation, it increased to 61.5% or 19% higher than the positive control (Lipofectamine 2000). In addition, compared with the positive control, our method showed less toxicity. Cell viability after transfection was 63.61%, 19% higher than with the standard transfection technique. In conclusion, we designed a new gene-delivery technique that is affordable, targeted, shows low-toxicity, yet high transfection efficiency, compared to other conventional approaches.The Graphical Abstract

scholarly journals Synthesis of Poly-Sodium-Acrylate (PSA) Coated Magnetic Nanoparticles for Use in Forward Osmosis Draw Solutions

2019 ◽  
Author(s):  
Irena Ban ◽  
Sabina Markuš ◽  
Sašo Gyergyek ◽  
Miha Drofenik ◽  
Jasmina Korenak ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Nanoparticles ◽  
External Magnetic Field ◽  
Osmotic Pressure ◽  
Forward Osmosis ◽  
Superparamagnetic Nanoparticles ◽  
Molar Ratio ◽  
Sodium Acrylate ◽  
Molar Ratios ◽  
Magnetite Phase

The synthesis of magnetic nanoparticles (MNPs) coated with hydrophilic poly-sodium-acrylate ligands (PSA) was studied to assess PSA-MNP complexes as draw solution (DS) solutes in forward osmosis (FO). For MNP-based DS, the surface modification and the size of the MNPs are two crucial factors to achieve a high osmolality. Superparamagnetic nanoparticles (NP) with functional groups attached may represent the ideal DS where chemical modifications of the NPs can be used in optimizing the DS osmolality and the magnetic properties allows for efficient recovery (DS re-concentration) using an external magnetic field. In this study MNPs with diameters of 4 nm have been prepared by controlled chemical co-precipitation of magnetite phase from aqueous solutions containing suitable salts of Fe2+ and Fe3+ under inert atmosphere and a pure magnetite phase could be verified by X-ray diffraction. Magnetic colloid suspensions containing PSA coated MNPs with three different molar ratios of PSA : MNP = 1:1, 1:2 and 1:3 were prepared and assessed in terms of osmotic pressure, aggregation propensity and magnetization. FTIR confirmed the presence of PSA on coated MNPs and pristine PSA-MNPs with a molar ratio PSA : MNP = 1:1 exhibited an osmotic pressure of 30 bar. Molar ratios of PSA : MNP = 1:2 and 1:3 lead to formation of less stabile magnetic colloid solutions which led to formation of aggregates with larger average hydrodynamic sizes and modest osmotic pressures (5.5 bar and 0.2 bar respectively). After purification with ultrafiltration, the 1:1 nanoparticles exhibited an osmotic pressure of 9 bar with no aggregation and a sufficient magnetization of 25 emu/g to allow for DS regeneration using an external magnetic field. However, it was observed that the amount of PSA molecules attached to the MNPs decreased during DS recycling steps leaving only strong chelate bonded core-shell PSA as coating on the MNPs. This demonstrates the crucial role of MNP coating robustness in designing an efficient MNP-based DS for FO.

Superparamagnetic Nanoparticle Delivery to the Cochlea Through Round Window by External Magnetic Field: Feasibility and Toxicity

2019 ◽  
Vol 26 (6) ◽  
pp. 646-655 ◽  
Author(s):  
Gaëlle Leterme ◽  
Caroline Guigou ◽  
Alexandra Oudot ◽  
Bertrand Collin ◽  
Julien Boudon ◽  
...  
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Histological Study ◽  
Round Window ◽  
Superparamagnetic Iron Oxide ◽  
Auditory Brainstem ◽  
Superparamagnetic Nanoparticles ◽  
Auditory Brainstem Responses ◽  
Auditory Thresholds ◽  
The Right

Introduction. The objective of this study was to evaluate the feasibility and toxicity of superparamagnetic iron oxide nanoparticles (SPIONs) administered into the cochlea through the round window (RW) by an external magnetic field. Materials and Methods. In 5 Wistar rats, the left RW was punctured. SPIONs suspended in hyaluronic gel (5 mg/mL) were applied in the RW niche and covered by a muscle graft. The nanoparticles were mobilized using a rare earth magnet (0.54 T) held in 4 consecutive positions around the head. The right ear served as control. Hearing function was monitored by auditory brainstem responses (4-32 kHz tone bursts). Results. The auditory thresholds remained unchanged 1 month after the administration. The histological study of the cochleae showed that SPIONs were driven into the scala tympani in the basal turn, the second turn, and the apex. Conclusion. Superparamagnetic nanoparticles can be driven inside the cochlea toward the apex with a preserved hearing up to 1 month in rats.

scholarly journals Manipulation of isolated brain nerve terminals by an external magnetic field using D-mannose-coated γ-Fe2O3 nano-sized particles and assessment of their effects on glutamate transport

2014 ◽  
Vol 5 ◽  
pp. 778-788 ◽  
Author(s):  
Tatiana Borisova ◽  
Natalia Krisanova ◽  
Arsenii Borуsov ◽  
Roman Sivko ◽  
Ludmila Ostapchenko ◽  
...  
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Synaptic Vesicles ◽  
Superparamagnetic Nanoparticles ◽  
Nerve Terminals ◽  
Glutamatergic Neurotransmission ◽  
Key Characteristics ◽  
Brain Nerve Terminals ◽  
Extracellular Level ◽  
Potential Use

The manipulation of brain nerve terminals by an external magnetic field promises breakthroughs in nano-neurotechnology. D-Mannose-coated superparamagnetic nanoparticles were synthesized by coprecipitation of Fe(II) and Fe(III) salts followed by oxidation with sodium hypochlorite and addition of D-mannose. Effects of D-mannose-coated superparamagnetic maghemite (γ-Fe2O3) nanoparticles on key characteristics of the glutamatergic neurotransmission were analysed. Using radiolabeled L-[14C]glutamate, it was shown that D-mannose-coated γ-Fe2O3 nanoparticles did not affect high-affinity Na+-dependent uptake, tonic release and the extracellular level of L-[14C]glutamate in isolated rat brain nerve terminals (synaptosomes). Also, the membrane potential of synaptosomes and acidification of synaptic vesicles was not changed as a result of the application of D-mannose-coated γ-Fe2O3 nanoparticles. This was demonstrated with the potential-sensitive fluorescent dye rhodamine 6G and the pH-sensitive dye acridine orange. The study also focused on the analysis of the potential use of these nanoparticles for manipulation of nerve terminals by an external magnetic field. It was shown that more than 84.3 ± 5.0% of L-[14C]glutamate-loaded synaptosomes (1 mg of protein/mL) incubated for 5 min with D-mannose-coated γ-Fe2O3 nanoparticles (250 µg/mL) moved to an area, in which the magnet (250 mT, gradient 5.5 Т/m) was applied compared to 33.5 ± 3.0% of the control and 48.6 ± 3.0% of samples that were treated with uncoated nanoparticles. Therefore, isolated brain nerve terminals can be easily manipulated by an external magnetic field using D-mannose-coated γ-Fe2O3 nanoparticles, while the key characteristics of glutamatergic neurotransmission are not affected. In other words, functionally active synaptosomes labeled with D-mannose-coated γ-Fe2O3 nanoparticles were obtained.

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