scholarly journals A focus of the nanoprecipitation by solvent displacement: example of poly(MAOTIB) intended to in vivo applications

2019 ◽  
Vol 1 (1) ◽  
pp. 20-26
Author(s):  
Justine Wallyn ◽  
Thierry Vandamme ◽  
Nicolas Anton
Keyword(s):  
Particle Concentration ◽  
Polymeric Nanoparticles ◽  
Iodine Concentration ◽  
The Other ◽  
Solvent Ratio ◽  
Final Particle ◽  
X Ray ◽  
X Ray Imaging ◽  
Solvent Displacement

Through this study, we propose to specifically focus on a particular stage of the fabrication of polymeric nanoparticles intended to be used as contrast agent for biomedical X-ray imaging. These nanoparticles, made from nanoprecipitation of preformed polymer, poly(MAOTIB) (poly(2-methacryloyloxyethyl(2,3,5-triiodobenzoate))) follow a solvent displacement process. This method, widely used in literature, is sensitive to the formulation and process parameters such as nature and concentrations of surfactant and polymer, solvent / non-solvent ratio, rate of addition of one phase in the other one, respective volumes of the phase, and homogenization shearing rate. On the other hand, in function of the aimed administration route, the final suspension should obey to specific constraints on final product, e.g. size range and polydispersity, final particle concentration (i.e. iodine concentration) and surfactant concentration. In the present work, we report a specific investigation on the nanoprecipiation of poly(MAOTIB) in tetrahydrofuran, dropped in water or ethanol (as non-solvent) and stabilized by nonionic surfactant. The objective is to show and explain the potentials and limitations of such the process, but also to provide a guidance on the way to optimize it.

scholarly journals Visualizing treatment delivery and deposition in mouse lungs using in vivo x-ray imaging

2019 ◽  
Vol 307 ◽  
pp. 282-291 ◽  
Author(s):  
Regine Gradl ◽  
Martin Dierolf ◽  
Lin Yang ◽  
Lorenz Hehn ◽  
Benedikt Günther ◽  
...  
Keyword(s):  
Treatment Delivery ◽  
X Ray ◽  
X Ray Imaging ◽  
Mouse Lungs

Development of a Mercuric Iodide Detector Array For In-Vivo X-Ray Imaging

1994 ◽  
Vol 38 ◽  
pp. 615-624
Author(s):  
Bradley E. Patt ◽  
Jan S. Iwanczyk ◽  
Martin P. Tornai ◽  
Craig S. Levin ◽  
Edward J. Hoffman
Keyword(s):  
Gamma Camera ◽  
Gamma Ray ◽  
Active Area ◽  
Detector Array ◽  
Mercuric Iodide ◽  
X Ray ◽  
X Ray Imaging ◽  
Spatial Performance ◽  
Gamma Ray Imaging

Abstract A nineteen element mercuric iodide (HgI2) detector array has been developed in order to investigate the potential of using this technology for in-vivo x-ray and gamma-ray imaging. A prototype cross-grid detector array was constructed with hexagonal pixels of 1.9 mm diameter (active area = 3.28 mm2) and 0.2 mm thick septa. The overall detector active area is roughly 65 mm2. A detector thickness of 1.2 mm was used to achieve about 100% efficiency at 60 keV and 67% efficiency at 140 keV The detector fabrication, geometry and structure were optimized for charge collection and to minimize crosstalk between elements. A section of a standard high resolution cast-lead gamma-camera collimator was incorporated into the detector to provide collimation matching the discrete pixel geometry. Measurements of spectral and spatial performance of the array were made using 241-Am and 99m-Tc sources. These measurements were compared with similar measurements made using an optimized single HgI2 x-ray detector with active area of about 3 mm2 and thickness of 500 μm.

In vivo x-ray imaging of the respiratory system using synchrotron sources and a compact light source

2019 ◽  
Author(s):  
Kaye Morgan ◽  
Regine Gradl ◽  
Martin Dierolf ◽  
Christoph Jud ◽  
Benedikt Günther ◽  
...  
Keyword(s):  
Light Source ◽  
Respiratory System ◽  
X Ray ◽  
X Ray Imaging ◽  
Compact Light Source

scholarly journals X-ray Scatter Imaging of Hepatocellular Carcinoma in a Mouse Model Using Nanoparticle Contrast Agents

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Danielle Rand ◽  
Zoltan Derdak ◽  
Rolf Carlson ◽  
Jack R. Wands ◽  
Christoph Rose-Petruck
Keyword(s):  
Hepatocellular Carcinoma ◽  
Mouse Model ◽  
Contrast Agents ◽  
Malignant Tumors ◽  
Detection Methods ◽  
X Rays ◽  
X Ray ◽  
Enhanced Sensitivity ◽  
X Ray Imaging

Abstract Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide and is almost uniformly fatal. Current methods of detection include ultrasound examination and imaging by CT scan or MRI; however, these techniques are problematic in terms of sensitivity and specificity and the detection of early tumors (<1 cm diameter) has proven elusive. Better, more specific and more sensitive detection methods are therefore urgently needed. Here we discuss the application of a newly developed x-ray imaging technique called Spatial Frequency Heterodyne Imaging (SFHI) for the early detection of HCC. SFHI uses x-rays scattered by an object to form an image and is more sensitive than conventional absorption-based x-radiography. We show that tissues labeled in vivo with gold nanoparticle contrast agents can be detected using SFHI. We also demonstrate that directed targeting and SFHI of HCC tumors in a mouse model is possible through the use of HCC-specific antibodies. The enhanced sensitivity of SFHI relative to currently available techniques enables the x-ray imaging of tumors that are just a few millimeters in diameter and substantially reduces the amount of nanoparticle contrast agent required for intravenous injection relative to absorption-based x-ray imaging.

Iodine concentrations in the rat kidney measured by x-ray microanalysis

1998 ◽  
Vol 39 (1) ◽  
pp. 90-95 ◽  
Author(s):  
J. Ueda ◽  
A. Nygren ◽  
M. Sjöquist ◽  
E. Jacobsson ◽  
H. R. Ulfendahl ◽  
...  
Keyword(s):  
Renal Pelvis ◽  
Filtration Rate ◽  
Rat Kidney ◽  
Iodine Concentration ◽  
Proximal Tubules ◽  
The Other ◽  
X Ray ◽  
Single Nephron ◽  
Proximal Tubular ◽  
Puncture Technique

Purpose: To measure the iodine concentrations in the proximal tubules and renal pelvis after i.v. injections of contrast media (CM) at 1600 mg I/kg b.w., using a micro-puncture technique and X-ray microanalysis Material and Methods: The correlation between the viscosity of each CM and its iodine concentration was evaluated and the viscosity of the fluid in the proximal tubule and renal pelvis was estimated in rats Results: After iotrolan injection, the iodine concentration in the proximal tubular fluid had increased to values about three times higher than those reached with diatrizoate, iohexol and ioxaglate. Similarly, iotrolan tended to produce a higher iodine concentration in the renal pelvis than did the other CM. the urine viscosity in the renal pelvis was much higher after the iotrolan injection than after the other CM injections Conclusion: High urine viscosity after iotrolan injection can at least partly explain our previous findings of a prolonged increase in tubular hydrostatic pressure and a prolonged decrease in the single nephron glomerular filtration rate after administration of this CM

In Vivo X-Ray Imaging of Phosphor-Doped PDMS and Phosphor-Doped Aerogel Biomaterials

2015 ◽  
Vol 64 (16) ◽  
pp. 823-830 ◽  
Author(s):  
Stephen W. Allison ◽  
Ethan S. Baker ◽  
Kyle J. Lynch ◽  
Firouzeh Sabri
Keyword(s):  
X Ray ◽  
X Ray Imaging

scholarly journals Spc110 N-Terminal Domains Act Independently to Mediate Stable γ-Tubulin Small Complex Binding and γ-Tubulin Ring Complex Assembly

2018 ◽  
Author(s):  
Andrew Lyon ◽  
Alex Zelter ◽  
Shruthi Viswanath ◽  
Alison Maxwell ◽  
Richard Johnson ◽  
...  
Keyword(s):  
Structural Model ◽  
Coiled Coil ◽  
The Other ◽  
Assembly Process ◽  
X Ray ◽  
X Ray Crystallography ◽  
Small Complex ◽  
Ring Complex ◽  
Biochemical Analyses

AbstractMicrotubule (MT) nucleation in vivo is regulated by the γ-tubulin ring complex (γTuRC), an approximately 2-megadalton complex conserved from yeast to humans. In Saccharomyces cerevisiae, γTuRC assembly is a key point of regulation over the MT cytoskeleton. Budding yeast γTuRC is composed of seven γ-tubulin small complex (γTuSC) subassemblies which associate helically to form a template from which microtubules grow. This assembly process requires higher-order oligomers of the coiled-coil protein Spc110 to bind multiple γTuSCs, thereby stabilizing the otherwise low-affinity interface between γTuSCs. While Spc110 oligomerization is critical, its N-terminal domain (NTD) also plays a role that is poorly understood both functionally and structurally. In this work, we sought a mechanistic understanding of Spc110 NTD using a combination of structural and biochemical analyses. Through crosslinking-mass spectrometry (XL-MS), we determined that a segment of Spc110 coiled-coil is a major point of contact with γTuSC. We determined the structure of this coiled-coil segment by X-ray crystallography and used it in combination with our XL-MS dataset to generate an integrative structural model of the γTuSC-Spc110 complex. This structural model, in combination with biochemical analyses of Spc110 heterodimers lacking one NTD, suggests that the two NTDs within an Spc110 dimer act independently, one stabilizing association between Spc110 and γTuSC and the other stabilizing the interface between adjacent γTuSCs.

Soft X-ray activated NaYF4:Gd/Tb scintillating nanorods for in vivo dual-modal X-ray/X-ray-induced optical bioimaging

Nanoscale ◽  
2018 ◽  
Vol 10 (1) ◽  
pp. 342-350 ◽  
Author(s):  
Xiaolong Li ◽  
Zhenluan Xue ◽  
Mingyang Jiang ◽  
Youbin Li ◽  
Songjun Zeng ◽  
...  
Keyword(s):  
X Ray ◽  
X Ray Imaging ◽  
Good Biocompatibility

Soft X-ray-activated NaYF4:Gd/Tb nanoprobes with efficient green radioluminescence and good biocompatibility were developed for simultaneous X-ray imaging and X-ray-induced optical bioimaging.

scholarly journals In-vivo dark-field and phase-contrast x-ray imaging

2013 ◽  
Vol 3 (1) ◽  
Author(s):  
M. Bech ◽  
A. Tapfer ◽  
A. Velroyen ◽  
A. Yaroshenko ◽  
B. Pauwels ◽  
...  
Keyword(s):  
Phase Contrast ◽  
Dark Field ◽  
X Ray ◽  
X Ray Imaging
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