scholarly journals Effect of key parameters on synthesis of superparamagnetic nanoparticles (SPIONs)

2016 ◽  
Vol 2 (1) ◽  
pp. 529-532
Author(s):  
Ankit Malhotra ◽  
Felix Spieß ◽  
Corinna Stegelmeier ◽  
Christina Debbeler ◽  
Kerstin Lüdtke-Buzug
Keyword(s):  
Cross Correlation ◽  
Magnetic Particle ◽  
Amplitude Spectrum ◽  
Correlation Spectroscopy ◽  
Superparamagnetic Nanoparticles ◽  
Hysteresis Curve ◽  
Hydrodynamic Diameter ◽  
Magnetic Particle Imaging ◽  
Co Precipitation ◽  
Particle Imaging

AbstractThere are various methods to synthesize superparamagnetic nanoparticles (SPIONs) useful for MPI (magnetic particle imaging) and in therapy (Hypothermia) such as co-precipitation, hydrothermal reactions etc. In this research, the focus is to analyse the effects of crucial parameters such as effect of molecular mass of dextran and temperature of the co-precipitation. These parameters play a crucial role in the inherent magnetic properties of the resulting SPIONs. The amplitude spectrum and hysteresis curve of the SPIONs is analysed with MPS (magnetic particle spectrometer). PCCS (photon cross-correlation spectroscopy) measurements are done to analyse the size distribution of hydrodynamic diameter the resulting SPIONs.

scholarly journals Applications of PDEs inpainting to magnetic particle imaging and corneal topography

2019 ◽  
Vol 39 (4) ◽  
pp. 453-482 ◽  
Author(s):  
Andrea Andrisani ◽  
Rosa Maria Mininni ◽  
Francesca Mazzia ◽  
Giuseppina Settanni ◽  
Alessandro Iurino ◽  
...  
Keyword(s):  
Fourth Order ◽  
Magnetic Particle ◽  
Approximation Error ◽  
Medical Application ◽  
Superparamagnetic Nanoparticles ◽  
Corneal Surface ◽  
Radial Curvature ◽  
Magnetic Particle Imaging ◽  
Particle Imaging ◽  
Standard Approximation

In this work we propose a novel application of Partial Differential Equations (PDEs) inpainting techniques to two medical contexts. The first one concerning recovering of concentration maps for superparamagnetic nanoparticles, used as tracers in the framework of Magnetic Particle Imaging. The analysis is carried out by two set of simulations, with and without adding a source of noise, to show that the inpainted images preserve the main properties of the original ones. The second medical application is related to recovering data of corneal elevation maps in ophthalmology. A new procedure consisting in applying the PDEs inpainting techniques to the radial curvature image is proposed. The images of the anterior corneal surface are properly recovered to obtain an approximation error of the required precision. We compare inpainting methods based on second, third and fourth-order PDEs with standard approximation and interpolation techniques.

Hydrodynamic and magnetic fractionation of superparamagnetic nanoparticles for magnetic particle imaging

2015 ◽  
Vol 380 ◽  
pp. 266-270 ◽  
Author(s):  
Norbert Löwa ◽  
Patrick Knappe ◽  
Frank Wiekhorst ◽  
Dietmar Eberbeck ◽  
Andreas F. Thünemann ◽  
...  
Keyword(s):  
Magnetic Particle ◽  
Superparamagnetic Nanoparticles ◽  
Magnetic Particle Imaging ◽  
Particle Imaging ◽  
Magnetic Fractionation

scholarly journals Maghemite nanoparticles coated by methacrylamide-based polymer for magnetic particle imaging

2021 ◽  
Vol 23 (2) ◽  
Author(s):  
Vít Herynek ◽  
Michal Babič ◽  
Ondřej Kaman ◽  
Hana Charvátová ◽  
Mariana Veselá ◽  
...  
Keyword(s):  
Mössbauer Spectroscopy ◽  
Sodium Hypochlorite ◽  
Magnetic Particle ◽  
Colloidal Stability ◽  
Mossbauer Spectroscopy ◽  
Hydrodynamic Diameter ◽  
Mößbauer Spectroscopy ◽  
Magnetic Particle Imaging ◽  
Particle Imaging

AbstractA wise selection of tracers is critical for magnetic particle imaging (MPI). Most of the current tracers are based on superparamagnetic iron oxide nanoparticles (SPIONs) with a suitable coating. We prepared maghemite cores (γ-Fe2O3) by coprecipitation of Fe(II) and Fe(III) salts with ammonium hydroxide followed by oxidation with hydrogen peroxide and stabilization as an anionic (γ-Fe2O3⊖) or cationic colloid (γ-Fe2O3⨁). The cores were coated by poly(N-(2-hydroxypropyl)methacrylamide)-co-N-[2-(hydroxyamino)-2-oxo-ethyl]-2-methyl-prop-2-enamide. The particles were characterized by dynamic light scattering, transmission electron microscopy, X-ray diffraction, Mössbauer spectroscopy, tested in vitro in a field-free point MPI scanner, and compared to nanoparticles prepared by oxidation with sodium hypochlorite and to the commercially available Resovist®. The cores had an average diameter of 8.0 nm (γ-Fe2O3⨁) and 8.7 nm (γ-Fe2O3⊖); the hydrodynamic diameter was 88 nm. Zeta potential values for both positively charged (+52 mV) and negatively charged particles (–60 mV) provided for good colloidal stabilization. Spinel structure of maghemite was confirmed by Mössbauer spectroscopy. The uncoated γ-Fe2O3⨁ particles yielded an MPI signal lower (by 16 %) than Resovist; the coated ones reached 88 % of the Resovist signal. Anionic γ-Fe2O3⊖ particles reached a higher (uncoated particles, by 15 %) or comparable (coated ones) signal relative to Resovist with a substantially lower signal dispersion. Control particles prepared by oxidation with sodium hypochlorite scored the weakest results. To conclude, a suitable size, narrow size distribution, and colloidal stability predispose the synthetized particles for use as a tracer for MPI. The anionic particles provided a higher signal with a lower dispersion than commercial tracers.

scholarly journals The Applications of Magnetic Particle Imaging: From Cell to Body

Diagnostics ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 800
Author(s):  
Xiao Han ◽  
Yang Li ◽  
Weifeng Liu ◽  
Xiaojun Chen ◽  
Zeyu Song ◽  
...  
Keyword(s):  
Cell Tracking ◽  
Magnetic Particle ◽  
Tumor Imaging ◽  
Positive Contrast ◽  
Blood Pool ◽  
Superparamagnetic Nanoparticles ◽  
Surrounding Tissue ◽  
Background Signal ◽  
Magnetic Particle Imaging ◽  
Particle Imaging

Magnetic particle imaging (MPI) is a cutting-edge imaging technique that is attracting increasing attention. This novel technique collects signals from superparamagnetic nanoparticles as its imaging tracer. It has characteristics such as linear quantitativity, positive contrast, unlimited penetration, no radiation, and no background signal from surrounding tissue. These characteristics enable various medical applications. In this paper, we first introduce the development and imaging principles of MPI. Then, we discuss the current major applications of MPI by dividing them into four categories: cell tracking, blood pool imaging, tumor imaging, and visualized magnetic hyperthermia. Even though research on MPI is still in its infancy, we hope this discussion will promote interest in the applications of MPI and encourage the design of tracers tailored for MPI.

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