Development of samarium [32P] phosphate colloid for radiosynoviorthesis applications: Preparation, biological and preliminary clinical studies experience

Prediction of formation probability of rare earth uranates inside nuclear reactor fuel from the determined oxygen potential using a solid oxide galvanic cell

Phase diagrams of the Pr–U–O and Er–U–O systems were established from the Gibbs energy formation obtained using a galvanic cell.

Hydroxyapatite (HA) microparticles labeled with (32)P - A promising option in the radiation synovectomy for inflamed joints

In the present article we describe a systematic approach pursued for the synthesis of (32)P-labeled hydroxyapatite (HA) microparticles (1-10µm size range) using no carrier added (NCA) (32)P produced in a nuclear reactor and animal evaluation of its utility as an expected viable radiopharmaceutical for the treatment of pain intensive arthrosis. NCA (32)P was produced via the (32)S(n,p)(32)P route in nuclear reactor with high radionuclidic purity (99.95±0.01%, n=5). Phosphorus-32-labeled hydroxyapatite microparticles (1-10µm size range) were synthesized with high radiochemical purity (99.0±0.3% n=12) under optimized conditions and the formulation showed excellent in vitro stability in saline as well as in rat serum. Intra-articular administration of the radiolabeled particles in the knee joints of normal Wistar rats showed near-complete retention of activity within the synovial cavity upto 1 month post-administration. The radiochemical formulation thus demonstrated promising features as a radiopharmaceutical for treatment of arthritis with excellent logistic advantage for shipment to sites distant from the production facility thanks to the suitable nuclear decay properties of (32)P.

Fabrication of Gd/Eu-codoped SmPO4 nanorods for dual-modal magnetic resonance and bio-optical imaging

Ln-based complexes can be used as T1-enhanced contrast agents of magnetic resonance (MR) imaging in clinical field. Herein, we present a facile and feasible biomineralization process to fabricate Gd/Eu-codoped SmPO4 nanorods (NRs) with silk fibroin (SF) peptides (codoped SF-NRs) as T1-enhanced contrast agents, which possess paramagnetic property, photoluminescence (PL), better cyto-/tissue-compatibility and longer half-life in blood due to SF coating on their surface. Their bio-distributions in TB-N mice via tail-vein injection indicated that, although SF-NRs could be safely cleared away through renal and fecal excretion, SF-NRs easily permeated and aggregated in tumors. The results of in vitro MR imaging demonstrate that the longitudinal relaxivity r1 value of codoped SF-NRs (0.31 Sm-Gd mM(-1) s(-1)) is not only significantly higher than those of Gd-doped and Eu-doped SmPO4 SF-NRs, but also higher than those of codoped pure NRs. The tests of in vivo T1 weighted MR imaging via intro-tumor injection and tail-vein injection confirm that, compared to the pure NRs, the codoped SF-NRs exhibited higher positive signal-enhancement ability. Furthermore, the better luminescence imaging of living cells under the fluorescence microscope (94% stronger than that of the NRs without SF). A formation mechanism of codoped SF-NRs is proposed, to explain the synergistic effect of Gd/Eu codoping and SF coating on their enhanced bio-compatibility, half-life in blood, T1-weighted MR imaging and PL imaging.

Selective lanthanide sorption and mechanism using novel hybrid Lewis base (N-methyl-N-phenyl-1,10-phenanthroline-2-carboxamide) ligand modified adsorbent

This study aims to develop a highly selective Lewis base adsorbent to investigate the selective sorption and recovery of Eu(III) and Sm(III) from wastewater. The oxygen and nitrogen donor atoms containing Lewis base N-methyl-N-phenyl-1,10-phenanthroline-2-carboxamide (MePhPTA) ligand was synthesized and subsequently an adsorbent was prepared by direct immobilization onto mesoporous silica. Determined maximum adsorption capacities were 125.63 and 124.38 mg/g for Eu(III) and Sm(III), respectively. Experiments with mixed-cations solutions showed that the sequence of preferential adsorption was Eu(III)>Sm(III). The lanthanide sorption by hybrid Lewis base adsorbent (HyLBA) was not adversely affected by the presence of sodium, potassium, calcium, magnesium, chloride, sulfate and nitrate ions due to strong affinity between hard Lewis acid lanthanide and hard Lewis base adsorbent. The crystallography for the Sm-MePhPTA complex suggested that MePhPTA was strongly coordinated to Sm(III) with oxygen and nitrogen by forming a stable complex with two 5-membered rings. The data clarified that bond lengths between Sm(III) and amide oxygen (2.475Å) were shorter than SmN (2.662Å) in phenanthroline moiety indicating strong oxygen driven HyLBA. The results suggested that HyLBA has a good prospect of promising applications for separation/sorption of lanthanide ions from effluents.

Intracellular localization of samarium in the lactating mammary gland cells: ultrastructural and microanalytical study

The frequent use of some rare earths in the medical and industrial domains make us worry about their intracellular behavior into the body. Reason for which we have investigated the subcellular localization of one of these elements, the samarium, in the mammary gland of lactating female wistar rats using two very sensitive methods of observation and microanalysis, the transmission electron microscopy and the secondary ion mass spectrometry. The ultrastructural study showed the presence of electron dense deposits in the lactating mammary glandular epithelial cell lysosomes of the samarium-treated rats, but no loaded lysosomes were observed in those of control rats. The microanalytical study allowed both the identification of the chemical species present in those deposits as samarium isotopes ((152) Sm(+)) and the cartography of its distribution. Our results confirm the previous ones showing that lysosomes of the glandular epithelial cells are the site of the intracellular concentration of foreign elements such as gallium. The intralysosomal deposits observed in the mammary glandular cells of the samarium-treated rats are similar in their form and density to those observed with the same element in other varieties of cells, such as liver, bone marrow, and spleen cells. Our ultrastructural and microanalytical results and those obtained in previous studies allow deducing that the intralysosomal deposits are very probably composed of an insoluble samarium phosphate salt.