PEG-copolymer-coated iron oxide nanoparticles that avoid the reticuloendothelial system and act as kidney MRI contrast agents.

In vitro experiments have shown the great potential of magnetic nanocarriers for multimodal imaging diagnosis and non-invasive therapies. However, their extensive clinical application is still jeopardized by a fast retention in the reticuloendothelial system (RES). The other issue that restrains their potential performance is slow degradation and excretion, which increases their risks of toxicity.

Nanostructured indium tin oxide slides for small-molecule profiling and imaging mass spectrometry of metabolites by surface-assisted laser desorption ionization MS.

Due to their electrical conductivity and optical transparency, slides coated with a thin layer of indium tin oxide (ITO) are the standard substrate for protein imaging mass spectrometry on tissue samples by MALDI-TOF MS. We have now studied the rf magnetron sputtering deposition parameters to prepare ITO thin films on glass substrates with the required nanometric surface structure for their use in the matrix-free imaging of metabolites and small-molecule drugs, without affecting the transparency required for classical histology. The custom-made surfaces were characterized by atomic force microscopy, scanning electron microscopy, ellipsometry, UV, and laser desorption ionization MS (LDI-MS) and employed for the LDI-MS-based analysis of glycans and druglike molecules, the quantification of lactose in milk by isotopic dilution, and metabolite imaging on mouse brain tissue samples.

Synthesis and evaluation of (13)N-labelled azo compounds for β-amyloid imaging in mice.

Purpose: The aim of the present study was to develop short half-lived tools for in vitro and in vivo β-amyloid imaging in mice, for which no suitable PET tracers are available.

Procedures: Five (13)N-labelled azo compounds (1-5) were synthesized using a three-step process using cyclotron-produced [(13)N]NO3 (-). Biodistribution studies were performed using positron emission tomography-computed tomography (PET-CT) on 20-month-old healthy, wild-type (WT) mice.

Synthesis and in vivo evaluation of (11) C-labeled (1,7-dicarba-closo-dodecaboran-1-yl)-N-{[(2S)-1-ethylpyrrolidin-2-yl]methyl}amide.

Boron clusters, and especially dicarba-closo-dodecaboranes, can be used as hydrophobic pharmacophores in the design of new drugs and radiotracers because of their hydrophobic character, spherical structure, and excellent chemical and photochemical stability. In the present paper, the synthesis and in vivo evaluation of (11) C-labeled (1,7-dicarba-closo-dodecaboran-1-yl)-N-{[(2S)-1-ethylpyrrolidin-2-yl]methyl}amide, an analog of the D2 receptor ligand [(11) C]raclopride, is described. The radiosynthesis was approached by reaction of the demethylated precursor with [(11) C]CH3 I in basic media; moderate radiochemical yields (18.

Assessing lung inflammation after nanoparticle inhalation using 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography imaging.

Purpose: The aim of the present study was to evaluate the use of 2-deoxy-2-[(18)F]fluoro-D-glucose ([(18)F]FDG) as a noninvasive strategy to assess the time course of inflammatory processes after inhalation of ZnO nanoparticles (NPs) in rats.

Procedures: Healthy, male Sprague-Dawley rats (n = 30) were divided in two groups of 15 animals each. Animals from one group (n = 15) were submitted to ZnO NPs inhalation in a chamber (10 nm to 4 μm particle size; maximum in number concentration, ∼ 200 nm; concentration = 245 mg/m(3)).

Biodistribution of different sized nanoparticles assessed by positron emission tomography: a general strategy for direct activation of metal oxide particles.

The extraordinary small size of NPs makes them difficult to detect and quantify once distributed in a material or biological system. We present a simple and straightforward method for the direct proton beam activation of synthetic or commercially available aluminum oxide NPs (Al2O3 NPs) via the 16O(p,α)13N nuclear reaction in order to assess their biological fate using positron emission tomography (PET). The radiolabeling of the NPs does not alter their surface or structural properties as demonstrated by TEM, DLS, and ζ-potential measurements.