A5047074261- Characterization and Applications of Magnetic Nanoparticles
- Advanced MRI Techniques and Applications
- Advanced NMR Techniques and Applications
- NMR spectroscopy and applications
- Nanoparticle-Based Drug Delivery
- Lanthanide and Transition Metal Complexes
- Iron Metabolism and Disorders
- Iron oxide chemistry and applications
- Hemoglobinopathies and Related Disorders
- Electron Spin Resonance Studies
- Trace Elements in Health
- Advanced Neuroimaging Techniques and Applications
- MRI in cancer diagnosis
- Atomic and Subatomic Physics Research
- Clay minerals and soil interactions
- Nanoplatforms for cancer theranostics
- Photoacoustic and Ultrasonic Imaging
- Chromium effects and bioremediation
- Dendrimers and Hyperbranched Polymers
- Gold and Silver Nanoparticles Synthesis and Applications
- Chemical Synthesis and Characterization
- Radioactive element chemistry and processing
- Electrostatics and Colloid Interactions
- Adsorption and biosorption for pollutant removal
- 3D Printing in Biomedical Research
University of Mons
2015-2025
Service de la Santé Publique
2014
Magnetic particles are very efficient Resonance Imaging (MRI) contrast agents. In the recent years, chemists have unleashed their imagination to design multi-functional nanoprobes for biomedical applications including MRI enhancement. This study is focused on direct relationship between size and magnetization of nuclear magnetic resonance relaxation properties, which condition efficiency. Experimental results with maghemite exhibiting a wide range sizes magnetizations compared previously...
Ultrasmall paramagnetic Gd2O3 nanoparticles have been developed as contrast agents for molecular and cellular preclinical MRI procedures. These small particles (mean diameter <5 nm) the highest Gd density of all agents. They generate strong positive enhancement in T1-weighted MRI. Signal is modulated by interactions water molecules with Gd, very provide optimal surface-to-volume ratios necessary to reach high relaxivities. Conventional nanocrystal synthesis techniques, subsequent...
Proteins implicated in iron homeostasis are assumed to be also involved the cellular processing of oxide nanoparticles. In this work, role an endogenous storage protein—namely ferritin—is examined remediation and biodegradation magnetic Previous vivo studies suggest intracellular transfer ions released during degradation nanoparticles protein cages within lysosomal compartments. Here, capacity ferritin accommodate store products is investigated vitro physiological acidic environment...
Near-infrared (NIR)-to-NIR upconverting NaY(Gd)F4 :Tm(3+) ,Yb(3+) paramagnetic nanoparticles (NPs) are efficiently detected by NIR imaging techniques. As they contain Gd(3+) ions, also provide efficient "positive" contrast in magnetic resonance (MRI). Water-dispersible small (≈25 nm, "S-") and ultrasmall (<5 nm diam., "US-") NPs synthesized thermal decomposition capped with citrate. The surface of citrate-coated US-NPs shows sodium depletion high Gd elemental ratios, as confirmed a...
Ultra-small gadolinium oxide nanoparticles (US-Gd2O3) are used to provide 'positive' contrast effects in magnetic resonance imaging (MRI), and being considered for molecular cellular applications. However, these can aggregate over time aqueous medium, as well when internalized into cells. This study is aimed at measuring vitro, the impact of aggregation on relaxometric properties paramagnetic US-Gd2O3 particles. First, nanoparticle core size behaviour was assessed by HRTEM. DLS (hydrodynamic...
Iron oxide superparamagnetic nanoparticles have been extensively studied as T2 contrast agents in magnetic resonance imaging. The theory of nuclear relaxation induced by has validated numerous experimental studies the case spherical particles. Recently, several focused on synthesis cubic nanoparticles. Some them reported significantly higher relaxivities compared to their counterpart and attributed this increase specific shapes. This work investigates impact cube-shaped through Monte Carlo...
Proton T1 and T2 in solutions of ferritin fercayl (a ferritin-like iron-dextran particle) were measured, over a wide range various parameters (Bo, temperature, interecho-time pH). The window the previously referred linear dependence 1/T2 on static field was increased, up to 500 MHz, independence echo time confirmed. Correlation times extracted from nuclear magnetic relaxation dispersion profiles. In pH studied, no strong variation relaxivities noticed. Fercayl, which, unlike ferritin,...
Mesoporous silica nanoparticles (MSNs) are used in drug delivery and cell tracking applications. As Mn(2+) is already implemented as a "positive" contrast agent preclinical imaging procedures (in the form of MnCl2 for neurological studies), introduction Mn porous network MSNs would allow labelling cells them using MRI. These particles general internalized endosomes, an acidic environment with high saline concentration. In addition, available MSN porosity could also serve carrier to deliver...
Understanding the relation between structure and reactivity of nanomaterials in organism is a crucial step towards efficient safe biomedical applications. The multi‐scale approach reported here, allows following magnetic structural transformations multicore maghemite nanoflowers medium mimicking intracellular lysosomal environment. By confronting atomic‐scale macroscopic information on biodegradation these complex nanostuctures, we can unravel mechanisms involved critical alterations their...
Abstract Hydrogels are widely used as cell scaffolds in several biomedical applications. Once implanted vivo, must often be visualized, and monitored overtime. However, appear poorly contrasted most imaging modalities such magnetic resonance (MRI). MRI is the technique of choice for high‐resolution visualization low‐density, water‐rich tissues. Attempts to enhance hydrogel contrast performed with “negative” agents that produce image artifacts impeding delineation implant's contours. In this...
The synthesis of iron oxide nanoparticles by coprecipitation ferrous and ferric ions was optimized in aqueous organic medium. For both syntheses, the influence different factors on nanoparticle size successfully evaluated "design experiments" method. This methodology allows finding very few runs optimal experimental conditions to synthesize with a predetermined radius. Aqueous syntheses magnetite seem be complementary. first one leads smaller (with radius comprised between 4.9 5.7 nm). These...
Magnetic resonance imaging has become a major diagnostic tool in modern medicine. MRI makes it possible to obtain highly contrasted body images without ionizing radiation. Using the magnetic properties of hydrogen protons, is at crossroads between physics, electronics, signal processing and informatics. In this introductory text, basic physical principles image formation are explained. Some important clinical applications also presented.
Manganese oxide (MnO) nanoparticles have been suggested as a promising "positive" MRI contrast agent for cellular and molecular studies. Mn-based agents could enable T(1)-weighted quantitative cell tracking procedures in vivo based on signal enhancement. In this study, ultrasmall MnO particles were synthesized coated with thiolated molecules (DMSA) polyethylene glycol (PEG) to allow enhanced labeling properties colloidal stability. This coating allowed the fabrication of individual (USPMnO)...
Abstract Ferritin, the iron‐storing protein, speeds up proton transverse magnetic relaxation in aqueous solutions. This T 2 shortening is used MRI to quantify iron brain and liver. Current theoretical models underestimate enhancement by ferritin at imaging fields, they do not predict measured dependence of rate on magnetization particles. Here it shown that a exchange dephasing model (PEDM) overcomes these limitations allowing first‐order mechanism. The PEDM considers between bulk water...
Gadolinium hydroxide and dysprosium oxide nanoparticles, which constitute a new interesting class of magnetic are characterized by different methods, using x-ray diffraction, magnetometry NMR relaxometry at multiple fields. The rod-like particles first shown to have simple paramagnetic behavior, like the bulk compound, without any influence nanometric size particles. Because their moment, these considerably shorten water relaxation times, especially transverse time high induced gadolinium is...
Mesoporous silica nanoparticles (MSNs) are being developed as drug delivery vectors. Biomedical imaging (MRI and PET) enables their tracking in vivo, provided surface is adequately grafted with probes (metal chelates). However, MSNs characterized by huge specific surfaces, high-quality metal chelate anchoring procedures must be validated, to demonstrate that detection vivo associated the presence of not detached chelates. MCM-48 nanospheres (M48SNs, 150 nm diam., 3-D pore geometry) were...
Abstract Ferritin, the iron‐storing protein of mammals, is known to darken T 2 ‐weighted MR images. This darkening could be used for non‐invasive measurement an organ's iron content. Unexplained discrepancies exist between data obtained in ferritin‐containing tissues and aqueous solutions ferritin. The clustering induced by trypsin evaluate effect ferritin agglomeration on relaxation rates. Although longitudinal not significantly influenced clustering, depends greatly stage agglomeration:...