Boosting Bismuth(III) Complexation for Targeted α-Therapy (TAT) Applications with the Mesocyclic Chelating Agent AAZTA.

Targeted α therapy (TAT) is a promising tool in the therapy of cancer. The radionuclide Bi shows favourable physical properties for this application, but the fast and stable chelation of this metal ion remains challenging. Herein, we demonstrate that the mesocyclic chelator AAZTA quickly coordinates Bi at room temperature, leading to a robust complex.

Water-Soluble [Tc(N)(PNP)] Moiety for Room-Temperature Tc Labeling of Sensitive Target Vectors.

The incorporation of bioactive molecules into a water-soluble [Tc][Tc(N)(PNP)]-based mixed compound is described. The method, which exploits the chemical properties of the new [Tc][Tc(N)(PNP3OH)] synthon [PNP3OH = ,-bis(di-hydroxymethylenphosphinoethyl)methoxyethylamine], was successfully applied to the labeling of small, medium (cysteine-functionalized biotin and c-RGDfK pentapeptide), and large molecules. Apomyoglobin was chosen as a model protein and derivatized site-specific enzymatic reaction catalyzed by transglutaminase (TGase) with the H-Cys-Gly-Lys-Gly-OH tetrapeptide for the insertion in the protein sequence of a reactive N-terminal Cys for Tc chelation.

Synthesis, radiolabeling, and pre-clinical evaluation of [Sc]Sc-AAZTA conjugate PSMA inhibitor, a new tracer for high-efficiency imaging of prostate cancer.

Purpose: The aim of this work was to demonstrate the suitability of AAZTA conjugated to PSMA inhibitor (B28110) labeled with scandium-44 as a new PET tracer for diagnostic imaging of prostate cancer.

Background: Nowadays, scandium-44 has received significant attention as a potential radionuclide with favorable characteristics for PET applications. A polyaminopolycarboxylate heptadentate ligand based on a 1,4-diazepine scaffold (AAZTA) has been thoroughly studied as chelator for Gd ions for MRI applications.

Increased incidence of infection in patients with myelofibrosis and transfusion-associated iron overload in the clinical setting.

Transfusion-associated iron overload may lead to increased risk of infection, but its role in myelofibrosis (MF) has been scarcely explored. We evaluated 106 consecutive patients with primary or secondary MF. Up to 38% of patients were transfusion-dependent (TD) with a median of 14 RBC units received.

Environment-specific spectral modeling: A new tool for the analysis of biological specimens.

The recent discovery of fluorescent dyes for improving pathologic tissues identification has highlighted the need of robust methods for performance validation especially in the field of fluorescence-guided surgery. Optical imaging of excised tissue samples is the reference tool to validate the association between dyes localization and the underlying histology in a controlled environment. Spectral unmixing may improve the validation process discriminating dye from endogenous signal.

Development and validation of a new HPLC-MS method for meglumine impurity profiling.

We report a new High Performance Liquid Chromatography-Mass Spectrometry (HPLC-MS) method to rapidly detect and quantify meglumine by-products (specifically reducing sugar(s) and nitrogen impurities) that could be present in the meglumine samples. Meglumine is a secondary amine obtained from glucose and it is an excipient used as counter-ion in several pharmaceutical formulations, especially when the concentration of the active pharmaceutical ingredient (API) is so high that the sodium is not a suitable option. Moreover, the increased use of meglumine is related to its ability to improve solubility in aqueous solutions due to the presence of a large number of hydroxyl groups.

In vivo tumor targeting and biodistribution evaluation of paramagnetic solid lipid nanoparticles for magnetic resonance imaging.

The current study was performed to evaluate the in vivo efficiency of a new nano-sized contrast agent called paramagnetic Solid Lipid Nanoparticles, pSLNs, having promising relaxivity properties for Magnetic Resonance Imaging application. Good stability and stealth properties toward macrophage uptake have been demonstrated. An in vivo MRI study resulted in an improved signal enhancement in the tumor tissue particularly when folate as targeting ligand was used to decorate the nanoparticles surface.

Paramagnetic solid lipid nanoparticles as a novel platform for the development of molecular MRI probes.

Highly efficient magnetic resonance imaging (MRI) probes have been prepared by loading Gd(III) complexes on the surface of solid lipid nanoparticles (pSLNs). Applicability as molecular imaging probes is demonstrated by an in vitro model study with targeted pSLNs.

Matrix-assisted laser desorption ionization imaging mass spectrometry detection of a magnetic resonance imaging contrast agent in mouse liver.

The present paper describes the detection of a magnetic resonance imaging (MRI) contrast agent by matrix-assisted laser desorption ionization imaging mass spectrometry (MALDI-IMS). The contrast agent was analyzed in both frozen and paraformaldehyde-fixed mouse livers explanted after its in vivo administration, and its identity was confirmed by fragmentation experiments. Moreover, a semiquantitative analysis was performed, evaluating its content in livers from mice sacrificed at different postadministration times.

Characterization of human hair melanin and its degradation products by means of magnetic resonance techniques.

Melanin granules (MGs) have been extracted from human Chinese black hairs by either acid hydrolysis (CH-type MGs) or enzymatic digestion (CP-type MGs), and their chemical structure investigated at the solid state by means of (13)C cross polarization magic angle spinning (CPMAS NMR) and EPR spectroscopy. Both types of MGs contain a large amount of protein that is tightly bound to the true melanin polymer, with CP-type MGs having a larger protein content than CH-type ones. Moreover, MGs may also contain variable amounts of lipid-like material.

[Os(bpy)2(CO)(enIA)][OTf]2: a novel sulfhydryl-specific metal-ligand complex.

The synthesis and physical-chemical characterization of the metal-ligand complex [Os(bpy)2(CO)(enIA)][OTf]2 (where enIA = ethylenediamine iodoacetamide) with a sulfhydryl-specific functional group is described. The UV and visible absorption and luminescence emission, including lifetime and steady-state anisotropy, are reported for the free probe and the probe covalently linked to two test proteins. The spectroscopic properties of the probe are unaffected by chemical modification and subsequent covalent linkage to the proteins.