Organ uptake, toxicity and skin clearance of ruthenium contrast agents monitored by x-ray fluorescence.

To investigate the distribution and toxicity of ruthenium nanoparticles (Ru NPs) injected intravenously in mice. We synthesized Ru NPs, followed their biodistribution by x-ray fluorescence (XRF) imaging and evaluated organ toxicity by histopathology and gene expression. Ru NPs accumulated, mainly in liver and spleen, where they were phagocyted by tissue macrophages, giving a transient inflammation and oxidative stress response that declined after 2 weeks.

XFCT-MRI hybrid multimodal contrast agents for complementary imaging.

Multimodal contrast agents in biomedical imaging enable the collection of more comprehensive diagnostic information. In the present work, we design hybrid ruthenium-decorated superparamagnetic iron oxide nanoparticles (NPs) as the contrast agents for both magnetic resonance imaging (MRI) and X-ray fluorescence computed tomography (XFCT). The NPs are synthesized a one-pot polyol hot injection route, in diethylene glycol.

Optical and X-ray Fluorescent Nanoparticles for Dual Mode Bioimaging.

Nanoparticle (NP) based contrast agents detectable via different imaging modalities (multimodal properties) provide a promising strategy for noninvasive diagnostics. Core-shell NPs combining optical and X-ray fluorescence properties as bioimaging contrast agents are presented. NPs developed earlier for X-ray fluorescence computed tomography (XFCT), based on ceramic molybdenum oxide (MoO) and metallic rhodium (Rh) and ruthenium (Ru), are coated with a silica (SiO) shell, using ethanolamine as the catalyst.

Synthesis, Physicochemical Characterization, and Cytotoxicity Assessment of Rh Nanoparticles with Different Morphologies-as Potential XFCT Nanoprobes.

Morphologically controllable synthesis of Rh nanoparticles (NPs) was achieved by the use of additives during polyol synthesis. The effect of salts and surfactant additives including PVP, sodium acetate, sodium citrate, CTAB, CTAC, and potassium bromide on Rh NPs morphology was investigated. When PVP was used as the only additive, trigonal NPs were obtained.

Nitric oxide-dependent biodegradation of graphene oxide reduces inflammation in the gastrointestinal tract.

Understanding the biological fate of graphene-based materials such as graphene oxide (GO) is crucial to assess adverse effects following intentional or inadvertent exposure. Here we provide first evidence of biodegradation of GO in the gastrointestinal tract using zebrafish as a model. Raman mapping was deployed to assess biodegradation.

Longitudinal In-Vivo X-Ray Fluorescence Computed Tomography With Molybdenum Nanoparticles.

X-ray fluorescence computed tomography (XFCT) with nanoparticles (NPs) as contrast agents shows potential for molecular biomedical imaging with higher spatial resolution than present methods. To date the technique has been demonstrated on phantoms and mice, however, parameters such as radiation dose, exposure times and sensitivity have not yet allowed for high-spatial-resolution in vivo longitudinal imaging, i.e.

Synthesis and Cytotoxicity Studies on Ru and Rh Nanoparticles as Potential X-Ray Fluorescence Computed Tomography (XFCT) Contrast Agents.

X-ray fluorescence computed tomography (XFCT) is an emerging biomedical imaging technique, which demands the development of new contrast agents. Ruthenium (Ru) and rhodium (Rh) have spectrally attractive K edge energies, qualifying them as new XFCT bio-imaging probes. Metallic Ru and Rh nanoparticles are synthesized by polyol method, in the presence of a stabilizer.

Effects of the Antimicrobial Peptide LL-37 and Innate Effector Mechanisms in Colistin-Resistant With Insertions.

Background: Colistin is a polypeptide antibiotic drug that targets lipopolysaccharides in the outer membrane of Gram-negative bacteria. Inactivation of the -gene is a common mechanism behind colistin-resistance in (Kpn). Since colistin is a cyclic polypeptide, it may exhibit cross-resistance with the antimicrobial peptide LL-37, and with other innate effector mechanisms, but previous results are inconclusive.

A Library of Potential Nanoparticle Contrast Agents for X-Ray Fluorescence Tomography Bioimaging.

Nanoparticles (NPs) have been used as contrast agents for several bioimaging modalities. X-ray fluorescence (XRF) tomography can provide sensitive and quantitative 3D detection of NPs. With spectrally matched NPs as contrast agents, we demonstrated earlier in a laboratory system that XRF tomography could achieve high-spatial-resolution tumor imaging in mice.

High-spatial-resolution x-ray fluorescence tomography with spectrally matched nanoparticles.

Present macroscopic biomedical imaging methods provide either morphology with high spatial resolution (e.g. CT) or functional/molecular information with lower resolution (e.

Reaction control of metal-assisted chemical etching for silicon-based zone plate nanostructures.

Metal-assisted chemical etching (MACE) reaction parameters were investigated for the fabrication of specially designed silicon-based X-ray zone plate nanostructures using a gold catalyst pattern and etching solutions composed of HF and HO. Etching depth, zone verticality and zone roughness were studied as a function of etching solution composition, temperature and processing time. Homogeneous, vertical etching with increasing depth is observed at increasing HO concentrations and elevated processing temperatures, implying a balance in the hole injection and silica dissolution kinetics at the gold-silicon interface.

Graphene oxide is degraded by neutrophils and the degradation products are non-genotoxic.

Neutrophils were previously shown to digest oxidized carbon nanotubes through a myeloperoxidase (MPO)-dependent mechanism, and graphene oxide (GO) was found to undergo degradation when incubated with purified MPO, but there are no studies to date showing degradation of GO by neutrophils. Here we produced endotoxin-free GO by a modified Hummers' method and asked whether primary human neutrophils stimulated to produce neutrophil extracellular traps or activated to undergo degranulation are capable of digesting GO. Biodegradation was assessed using a range of techniques including Raman spectroscopy, transmission electron microscopy, atomic force microscopy, and mass spectrometry.

Proteomics Analysis Reveals Distinct Corona Composition on Magnetic Nanoparticles with Different Surface Coatings: Implications for Interactions with Primary Human Macrophages.

Superparamagnetic iron oxide nanoparticles (SPIONs) have emerged as promising contrast agents for magnetic resonance imaging. The influence of different surface coatings on the biocompatibility of SPIONs has been addressed, but the potential impact of the so-called corona of adsorbed proteins on the surface of SPIONs on their biological behavior is less well studied. Here, we determined the composition of the plasma protein corona on silica-coated versus dextran-coated SPIONs using mass spectrometry-based proteomics approaches.

Laboratory x-ray fluorescence tomography for high-resolution nanoparticle bio-imaging.

We demonstrate that nanoparticle x-ray fluorescence computed tomography in mouse-sized objects can be performed with very high spatial resolution at acceptable dose and exposure times with a compact laboratory system. The method relies on the combination of the 24 keV line-emission from a high-brightness liquid-metal-jet x-ray source, pencil-beam-forming x-ray optics, photon-counting energy-dispersive detection, and carefully matched (Mo) nanoparticles. Phantom experiments and simulations show that the arrangement significantly reduces Compton background and allows 100 μm detail imaging at dose and exposure times compatible with small-animal experiments.

Bridge over troubled waters: understanding the synthetic and biological identities of engineered nanomaterials.

Engineered nanomaterials offer exciting opportunities for 'smart' drug delivery and in vivo imaging of disease processes, as well as in regenerative medicine. The ability to manipulate matter at the nanoscale enables many new properties that are both desirable and exploitable, but the same properties could also give rise to unexpected toxicities that may adversely affect human health. Understanding the physicochemical properties that drive toxicological outcomes is a formidable challenge as it is not trivial to separate and, hence, to pinpoint individual material characteristics of nanomaterials.

Efficient internalization of silica-coated iron oxide nanoparticles of different sizes by primary human macrophages and dendritic cells.

Engineered nanoparticles are being considered for a wide range of biomedical applications, from magnetic resonance imaging to "smart" drug delivery systems. The development of novel nanomaterials for biomedical applications must be accompanied by careful scrutiny of their biocompatibility. In this regard, particular attention should be paid to the possible interactions between nanoparticles and cells of the immune system, our primary defense system against foreign invasion.