scholarly journals Characterization of iron-doped crystalline silicon nanoparticles and their modification with citrate anions for in vivo applications

2021 ◽  
Vol 16 (5) ◽  
pp. 414-425
Author(s):  
K. I. Rozhkov ◽  
E. Y. Yagudaeva ◽  
S. V. Sizova ◽  
M. A. Lazov ◽  
E. V. Smirnova ◽  
...  
Keyword(s):  
Structural Properties ◽  
Emission Spectroscopy ◽  
Silicon Nanoparticles ◽  
Crystalline Silicon ◽  
Synthesis Method ◽  
Oxide Shell ◽  
Hydrodynamic Diameter ◽  
Plasma Chemical ◽  
Iron Doped

Objectives. This paper presents data on the development and study of the structural properties of iron-doped crystalline silicon (nc-Si/SiOx/Fe) nanoparticles obtained using the plasma-chemical method for application in magnetic resonance imaging diagnostics and treatment of oncological diseases. This work aimed to use a variety of analytical methods to study the structural properties of nc-Si/SiOx/Fe and their colloidal stabilization with citrate anions for in vivo applications.Methods. Silicon nanoparticles obtained via the plasma-chemical synthesis method were characterized by laser spark emission spectroscopy, atomic emission spectroscopy, Fouriertransform infrared spectroscopy, and X-ray photoelectron spectroscopy. The hydrodynamic diameter of the nanoparticles was estimated using dynamic light scattering. The toxicity of the nanoparticles was investigated using a colorimetric MTT test for the cell metabolic activity. Elemental iron with different Fe/Si atomic ratios was added to the feedstock during loading.Results. The particles were shown to have a large silicon core covered by a relatively thin layer of intermediate oxides (interface) and an amorphous oxide shell, which is silicon oxide with different oxidation states SiOx (0 ≤ x ≤ 2). The samples had an iron content of 0.8–1.8 at %. Colloidal solutions of the nanoparticles stabilized by citrate anions were obtained and characterized. According to the analysis of the cytotoxicity of the modified nanosilicon particles using monoclonal K562 human erythroleukemia cells, no toxicity was found for cells in culture at particle concentrations of up to 5 µg/mL.Conclusions. Since the obtained modified particles are nontoxic, they can be used in in vivo theranostic applications.

Silicon nanoparticles with iron impurities for multifunctional applications

2020 ◽  
Vol 13 (04) ◽  
pp. 2040007
Author(s):  
Yu. V. Kargina ◽  
S. V. Zinovyev ◽  
A. M. Perepukhov ◽  
E. V. Suslova ◽  
A. A. Ischenko ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Silicon Nanoparticles ◽  
Crystalline Silicon ◽  
Proton Relaxation ◽  
Hydrodynamic Diameter ◽  
Transmission Electron ◽  
Fe Content ◽  
Si Nanoparticles ◽  
Magnetic Resonance Imaging Mri

Crystalline silicon (Si) nanoparticles (NPs) doped with iron (Fe) in the range from 0.02 to 2.5 at.% were prepared by plasma-ablative synthesis and were investigated by means of the transmission electron microscopy, X-ray diffraction (XRD), dynamic light scattering (DLS), infrared spectroscopy and nuclear magnetic resonance relaxometry. While the nanocrystal size in Si:Fe NPs did not depend significantly on Fe content, the hydrodynamic diameter of NPs in aqueous suspensions increases from 50 to 180[Formula: see text]nm. Both the transverse and longitudinal proton relaxation time were found to decrease in the prepared suspensions of Si:Fe NPs. Maximal shortening of the transverse relaxion was observed for Si:Fe NPs with 0.2 at.% of Fe and the relaxation rate was almost linearly proportional to the NP concentration. Both these findings and in vivo tests indicate that Si:Fe NPs are promising for biomedical applications in magnetic resonance imaging (MRI) and therapy of cancer.

scholarly journals Improved synthesis of SV2A targeting radiotracer [11C]UCB-J

2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Johanna Rokka ◽  
Eva Schlein ◽  
Jonas Eriksson
Keyword(s):  
Methyl Iodide ◽  
Water Solution ◽  
Synthesis Method ◽  
Radiochemical Yield ◽  
Preparative Hplc ◽  
Step Method ◽  
Synaptic Density ◽  
Excellent Starting Point ◽  
Starting Point

Abstract Introduction [11C]UCB-J is a tracer developed for PET (positron emission tomography) that has high affinity towards synaptic vesicle glycoprotein 2A (SV2A), a protein believed to participate in the regulation of neurotransmitter release in neurons and endocrine cells. The localisation of SV2A in the synaptic terminals makes it a viable target for in vivo imaging of synaptic density in the brain. Several SV2A targeting compounds have been evaluated as PET tracers, including [11C]UCB-J, with the aim to facilitate studies of synaptic density in neurological diseases. The original two-step synthesis method failed in our hands to produce sufficient amounts of [11C]UCB-J, but served as an excellent starting point for further optimizations towards a high yielding and simplified one-step method. [11C]Methyl iodide was trapped in a clear THF-water solution containing the trifluoroborate substituted precursor, potassium carbonate and palladium complex. The resulting reaction mixture was heated at 70 °C for 4 min to produce [11C]UCB-J. Results After semi-preparative HPLC purification and reformulation in 10% ethanol/phosphate buffered saline, the product was obtained in 39 ± 5% radiochemical yield based on [11C]methyl iodide, corresponding to 1.8 ± 0.5 GBq at EOS. The radiochemical purity was > 99% and the molar activity was 390 ± 180 GBq/μmol at EOS. The product solution contained < 2 ppb palladium. Conclusions A robust and high yielding production method has been developed for [11C]UCB-J, suitable for both preclinical and clinical PET applications.

Development of the IR laser pyrolysis for the synthesis of iron–doped TiO2 nanoparticles: Structural properties and photoactivity

2010 ◽  
Vol 53 (2) ◽  
pp. 94-102 ◽  
Author(s):  
R. Alexandrescu ◽  
I. Morjan ◽  
M. Scarisoreanu ◽  
R. Birjega ◽  
C. Fleaca ◽  
...  
Keyword(s):  
Tio2 Nanoparticles ◽  
Structural Properties ◽  
Doped Tio2 ◽  
Laser Pyrolysis ◽  
Ir Laser ◽  
Iron Doped

Facile Preparation of Liposomes-encapsulated Zn-DTPA from Soy Lecithin for Decorporation of Radioactive Actinides

2021 ◽  
Author(s):  
Manal Almalki ◽  
Edward Lai ◽  
Raymond Ko ◽  
Chunsheng Li
Keyword(s):  
Pulmonary Delivery ◽  
Spherical Shape ◽  
Hydrodynamic Diameter ◽  
Cytotoxicity Test ◽  
Soy Lecithin ◽  
Short Period ◽  
Pharmacokinetic Properties ◽  
Facile Preparation ◽  
In Vivo Cytotoxicity

Diethylenetriaminepentaacetic acid (DTPA) is an attractive decorporation agent that can enhance the excretion of radioactive actinides such as plutonium, americium, and curium after a radiological incident. However, DTPA is excreted in a short period of time after administration. Several formulations have been developed to improve DTPA pharmacokinetic properties. In this project, liposomes were prepared facilely from soy lecithin as a nanocarrier for pulmonary delivery of Zn-DTPA. Lipid hydration, reverse phase evaporation, and mechanical sonication were three methods evaluated for the preparation of liposomes-encapsulated Zn-DTPA. Mechanical sonication was the method of choice due to simple apparatus and facile preparation. Liposomes-encapsulated Zn-DTPA (lipo-Zn-DTPA) exhibited a hydrodynamic diameter of 178(±2) nm and a spherical shape. The loading capacity and encapsulation efficiency of Zn-DTPA were 41(±5) mg/g and 10(±1)%, respectively. Lyophilization of lipo-Zn-DTPA for extended storage did not affect the amount of encapsulated drug or damage the structure of liposomes. An in vivo cytotoxicity test confirmed no serious adverse effect of Zn-DTPA encapsulated lecithin liposomes in rats.

Structural Properties of Amorphous Silicon Produced by Electron Irradiation

1999 ◽  
Vol 557 ◽  
Author(s):  
J. Yamasaki ◽  
S. Takeda
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Distribution Function ◽  
Structural Properties ◽  
Electron Irradiation ◽  
Low Temperatures ◽  
Crystalline Silicon ◽  
Transmission Electron ◽  
Amorphous Si ◽  
Means Of Transmission

AbstractThe structural properties of the amorphous Si (a-Si), which was created from crystalline silicon by 2 MeV electron irradiation at low temperatures about 25 K, are examined in detail by means of transmission electron microscopy and transmission electron diffraction. The peak positions in the radial distribution function (RDF) of the a-Si correspond well to those of a-Si fabricated by other techniques. The electron-irradiation-induced a-Si returns to crystalline Si after annealing at 550°C.

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