Low-energy Auger and conversion electron spectroscopy of Mo β-decay.

The preparation of nanometer-thick molybdenum-99 (Mo) sources using the droplet deposition method was investigated. The quality of these prepared sources was analyzed using scanning electron microscopy (SEM), electron Rutherford backscattering (ERBS) techniques, and Geant4 simulations. The emitted electrons resulting from the β-decay of the prepared Mo sources, with energies below 2.

Tunable and noncytotoxic PET/SPECT-MRI multimodality imaging probes using colloidally stable ligand-free superparamagnetic iron oxide nanoparticles.

Physiologically stable multimodality imaging probes for positron emission tomography/single-photon emission computed tomography (PET/SPECT)-magnetic resonance imaging (MRI) were synthesized using the superparamagnetic maghemite iron oxide (γ-FeO) nanoparticles (SPIONs). The SPIONs were sterically stabilized with a finely tuned mixture of diblock copolymers with either methoxypolyethylene glycol (MPEG) or primary amine NH end groups. The radioisotope for PET or SPECT imaging was incorporated with the SPIONs at high temperature.

Synthesis and in Vivo Biological Evaluation of (68)Ga-Labeled Carbonic Anhydrase IX Targeting Small Molecules for Positron Emission Tomography.

Tumor hypoxia contributes resistance to chemo- and radiotherapy, while oxygenated tumors are sensitive to these treatments. The indirect detection of hypoxic tumors is possible by targeting carbonic anhydrase IX (CA IX), an enzyme overexpressed in hypoxic tumors, with sulfonamide-based imaging agents. In this study, we present the design and synthesis of novel gallium-radiolabeled small-molecule sulfonamides targeting CA IX.

The role of additives in moderating the influence of Fe(III) and Cu(II) on the radiochemical yield of [⁶⁸Ga(DOTATATE)].

[(68)Ga(DOTATATE)] has demonstrated its clinical usefulness. Both Fe(3+) and Cu(2+), potential contaminants in Gallium-68 generator eluent, substantially reduce the radiochemical (RC) yield of [(68)Ga(DOTATATE)] if the metal/ligand ratio of 1:1 is exceeded. A variety of compounds were examined for their potential ability to reduce this effect.

Rhenium and technetium tricarbonyl complexes of N-heterocyclic carbene ligands.

A strategy for the conjugation of N-heterocyclic carbene (NHC) ligands to biomolecules via amide bond formation is described. Both 1-(2-pyridyl)imidazolium or 1-(2-pyridyl)benzimidazolium salts functionalized with a pendant carboxylic acid group were prepared and coupled to glycine benzyl ester using 1-ethyl-3-(3-(dimethylamino)propyl)carbodiimide. A series of 10 rhenium(I) tricarbonyl complexes of the form [ReX(CO)3(ĈN)] (ĈN is a bidentate NHC ligand, and X is a monodentate anionic ligand: Cl(-), RCO2(-)) were synthesized via a Ag2O transmetalation protocol from the Re(I) precursor compound Re(CO)5Cl.

Triamidetriamine bearing macrobicyclic and macrotricyclic ligands: potential applications in the development of copper-64 radiopharmaceuticals.

A versatile and straightforward synthetic approach is described for the preparation of triamide bearing analogues of sarcophagine hexaazamacrobicyclic cage ligands without the need for a templating metal ion. Reaction of 1,1,1-tris(aminoethyl)ethane (tame) with 3 equiv of 2-chloroacetyl chloride, yields the tris(α-chloroamide) synthetic intermediate 6, which when treated with either 1,1,1-tris(aminoethyl)ethane or 1,4,7-triazacyclononane furnished two novel triamidetriamine cryptand ligands (7 and 8 respectively). The Co(III) and Cu(II) complexes of cryptand 7 were prepared; however, cryptand 8 could not be metalated.

Synthesis and radiolabelling of DOTA-linked glutamine analogues with ⁶⁷,⁶⁸Ga as markers for increased glutamine metabolism in tumour cells.

DOTA-linked glutamine analogues with a C₆- alkyl and polyethyleneglycol (PEG) chain between the chelating group and the L-glutamine moiety were synthesised and labelled with ⁶⁷,⁶⁸Ga using established methods. High yields were achieved for the radiolabelling of the molecules with both radionuclides (>90%), although conversion of the commercially available ⁶⁷Ga-citrate to the chloride species was a requirement for consistent high radiochemical yields. The generator produced ⁶⁸Ga was in the [⁶⁸Ga(OH)₄]⁻ form.

Binding of the Delta- and Lambda-Enantiomers of [Ru(dmphen)(2)dpq](2+) to the Hexanucleotide d(GTCGAC)(2).

1H NMR spectroscopy and viscosity measurements have been used to study the oligonucleotide binding of the Delta- and Lambda-enantiomers of the metal complex [Ru(dmphen)(2)dpq](2+) (dmphen = 2,9-dimethyl-1,10-phenanthroline and dpq = dipyrido[3,2-f:2',3'-h]quinoxaline). The addition of either enantiomer to d(GTCGAC)(2) induced large upfield shifts and significant broadening for the hexanucleotide imino and metal complex dpq resonances. These data coupled with the observed increase in the melting transition midpoint of the hexanucleotide duplex upon addition of either enantiomer suggests that both Delta- and Lambda-[Ru(dmphen)(2)dpq](2+) bind by intercalation.