Gadolinium Ions Research Articles

Thermal and structural modification in transparent and magnetic gallogermanate glasses induced by Gd2O3

A series of new transparent and magnetic barium gallogermanate glasses in the system ( x ) Gd 2 O 3 – (100- x ) [20BaO−15Ga 2 O 3 −65GeO 2 ] with x = 0, 8, 14, 18, 22 and 25 mol% were synthesized. Their thermal, structural and magnetic properties were characterized. Based on the differential scanning calorimetry results, one determined the composition domain exhibiting the highest thermal stability toward crystallization and provided a detailed experimental fabrication method for the production of optical fibers. The local glass structure investigated using combined Raman and Infrared vibrational spectroscopies shows a progressive depolymerization of the 3D glass germanate network accompanied with an increase of non-bridging oxygens when increasing the Gd 2 O 3 content. The incorporation of gadolinium ions tends to extend the IR transmission window. Thanks to the magnetic susceptibility measurements, the paramagnetic behavior was evidenced, and increases with the Gd 3+ content. The combination of the optical, thermal and magnetic properties of Gd 2 O 3 gallogermanate glasses as well as their ability to be shaped into optical fibers make them promising materials for their integration in MIR functional optical components. • Novel transparent and magnetic glasses in the system Gd 2 O 3 – BaO − Ga 2 O 3 − GeO 2 were synthesized by melt-quenching method. • Investigation of thermal, structural and magnetic properties. • Fabrication of paramagnetic fibers was demonstrated using preform-to-fiber approach. • The paramagnetic behavior was evidenced using the magnetic susceptibility measurements.

Influence of hydrogenation on the structural, optical and magnetic properties of Gd-incorporated WO3 nanocomposites synthesised by precipitation method

ABSTRACT Nanoparticlesof tungsten oxide combined with varying amounts of gadolinium ions were synthesised by a hydrochloric acid-assisted precipitation method. The powders were characterised by ; X-ray fluorescence (XRF), X-ray diffraction (XRD), diffuse reflectance (DRS), and magnetic measurements. The ordinary monoclinic structure of WO3 was transformed into one of its Magneli structures (W32O84) by the incorporation of a tiny Gd ions due to the variation in the local charge neutrality . Different magnetic behaviours of Gd-incorporated W-oxide were observed depending on the synthesis procedure including a hydrogenation. The hydrogenated Gd-incorporated W-oxide has FM-behaviour. However, the created FM properties were severely undermined by increasing the Gd inclusion to more than 1%, which was attributed to the effect of the Gd interionic separations and the minute solubility of Gd in of W-oxide. This study focuses on the conditions necessary to realise the creation of FM in W-oxide by Gd ions incorporation for many applications, such as optical phosphors and catalysts.

Cerium Oxide Nanoparticles with Entrapped Gadolinium for High T 1 Relaxivity and ROS-Scavenging Purposes.

Gadolinium chelates are employed worldwide today as clinical contrast agents for magnetic resonance imaging. Until now, the commonly used linear contrast agents based on the rare-earth element gadolinium have been considered safe and well-tolerated. Recently, concerns regarding this type of contrast agent have been reported, which is why there is an urgent need to develop the next generation of stable contrast agents with enhanced spin–lattice relaxation, as measured by improved T1 relaxivity at lower doses. Here, we show that by the integration of gadolinium ions in cerium oxide nanoparticles, a stable crystalline 5 nm sized nanoparticulate system with a homogeneous gadolinium ion distribution is obtained. These cerium oxide nanoparticles with entrapped gadolinium deliver strong T1 relaxivity per gadolinium ion (T1 relaxivity, r1 = 12.0 mM–1 s–1) with the potential to act as scavengers of reactive oxygen species (ROS). The presence of Ce3+ sites and oxygen vacancies at the surface plays a critical role in providing the antioxidant properties. The characterization of radial distribution of Ce3+ and Ce4+ oxidation states indicated a higher concentration of Ce3+ at the nanoparticle surfaces. Additionally, we investigated the ROS-scavenging capabilities of pure gadolinium-containing cerium oxide nanoparticles by bioluminescent imaging in vivo, where inhibitory effects on ROS activity are shown.

Gadolinium silicate-coated porous silicon nanoparticles as an MRI contrast agent and drug delivery carrier

A nano-formulation based on gadolinium silicate-coated porous silicon nanoparticles (pSiNPs) is newly disclosed as an MRI contrast agent and drug delivery carrier. In this study, a new surface coating method of pSiNPs using gadolinium ions (Gd3+) was introduced, and the resulting nanoparticles (named pSiNPs-Gd) showed T1-type MR responses and high drug encapsulation efficacy at the same time. The nanoparticle characterization, MR signal, cytotoxicity, and drug release profile were systematically analyzed. We believe our findings could contribute to the development of multi-functional pSiNPs-based nanotherapeutics and their applications in various fields.

A Facile and Universal Method for Preparing Polyethylene Glycol‐Metal Hybrid Nanoparticles and Their Application in Tumor Theranostics (Adv. Healthcare Mater. 12/2022)

Tumor Theranostics In article number 2200044 by Yan He, Xujie Liu, and co-workers, a facile and universal strategy is designed for assembling a range of functional metal ions into 31 types of polyethylene glycol (PEG)-metal hybrid nanoparticles (P-MNPs), which potentially expand the biomedical research of metal ions. As a proof-of-concept, four types P-MNPs containing copper, ruthenium, manganese, and gadolinium ions, respectively, are proven to be tailored for tumor theranostics.

Unimolecular Nano-contrast Agent with Ultrahigh Relaxivity and Very Long Retention for Magnetic Resonance Lymphography.

Magnetic resonance (MR) imaging is very important for noninvasive lymphography. However, the present MR contrast agents still cannot supply strong enough tissue contrast and long observation window. To improve the performance of contrast agents, we introduce one-dimensional unimolecular nanoparticles with a confined and compact poly(acrylic acid) core as nanoparticulate chelates of gadolinium ions. Thus, obtained nanoparticulate T1 contrast agents give r1 relaxivity as high as 136.3 mM-1·s-1 under 3.0 T. By injection at the footpad of mice, the contrast agents provide excellent contrast enhancement of lymphatic drainage and they may arrive at popliteal lymph nodes within 30 min and reside for more than 80 h. High performance of the present contrast agent is attributed to the confined and compact core of materials that increase hydration number, intershell water diffusion, and decrease rotational motion.

Dual peptide-engineered and gadolinium-doped polydopamine particles as targeted nanotheranostics for the treatment of osteosarcoma and related osteolysis

The treatment of malignant bone tumors such as osteosarcoma and tumor-associated bone destruction is challenging in clinic. Here, we designed a type of bone-targeted nanotheranostics to treat osteosarcoma. A bone targeting peptide consisting of eight aspartic acids and a tumor targeting peptide were conjugated onto polydopamine nanoparticles bearing gadolinium ions at different molar ratios. The optimized nanoformulation showed high photothermal efficiency, bone targeting affinity, and were efficiently accumulated at tumor site and osteolysis lesions after systematic administration. In addition, the peptide conjugated on nanoparticle surface efficiently inhibited osteoclast formation and bone destruction both in vitro and in vivo. As a result, the prepared nanoparticles combination with near-infrared laser irradiation efficiently inhibited tumor growth and tumor-associated bone resorption in an osteosarcoma xenograft mice model. This study provides a new nanotheranostic to treat osteosarcoma and related osteolysis.

Effects of Cations on HPTS Fluorescence and Quantification of Free Gadolinium Ions in Solution; Assessment of Intracellular Release of Gd3+ from Gd-Based MRI Contrast Agents.

8-Hydroxypyrene-1,3,6-trisulfonate (HPTS) is a small, hydrophilic fluorescent molecule. Since the pKa of the hydroxyl group is close to neutrality and quickly responds to pH changes, it is widely used as a pH-reporter in cell biology for measurements of intracellular pH. HPTS fluorescence (both excitation and emission spectra) at variable pH was measured in pure water in the presence of NaCl solution or in the presence of different buffers (PBS or hepes in the presence or not of NaCl) and in a solution containing BSA. pKa values have been obtained from the sigmoidal curves. Herein, we investigated the effect of mono-, di-, and trivalent cations (Na+, Ca2+, La3+, Gd3+) on fluorescence changes and proposed its use for the quantification of trivalent cations (e.g., gadolinium ions) present in solution as acqua-ions. Starting from the linear regression, the LoD value of 6.32 µM for the Gd3+ detection was calculated. The effects on the emission were also analyzed in the presence of a combination of Gd3+ at two different concentrations and the previously indicated mono and di-valent ions. The study demonstrated the feasibility of a qualitative method to investigate the intracellular Gd3+ release upon the administration of Gd-based contrast agents in murine macrophages.

Carbonized paramagnetic complexes of Mn (II) as contrast agents for precise magnetic resonance imaging of sub-millimeter-sized orthotopic tumors

Paramagnetic complexes containing gadolinium ions have been widely used for magnetic resonance imaging (MRI) in clinic. However, these paramagnetic complexes pose some safety concerns. There is still a demand for the development of stable MRI contrast agents that exhibit higher sensitivity and superior functionality to existing contrast agents. Here, we develop carbonized paramagnetic complexes of manganese (II) (Mn@CCs) to encapsulate Mn2+ in sealed carbonized shells with superhigh r1 relaxivity. Compared to the most common clinical contrast agent Magnevist, investigations in vivo demonstrate that the Mn@CCs cross the intact blood-brain barrier of normal health mice with minor metal deposition; preferentially target the glioma tissues distribute homogeneously with high penetration in an intracranial mouse model; delineate clear tumor margins in MRIs of ultrasmall single-nodule brain tumors, and multi-nodular liver tumors. The sensitivity, accuracy and low toxicity offer by Mn@CCs provides new opportunities for early molecular diagnostics and imaging-guided biomedical applications.

Luminescence of Terbium Ions in Aqueous Solutions of Sodium Styrene Sulfonate Copolymers with 4-Methacrylamidosalicylic Acid

Water-soluble copolymers of sodium styrene sulfonate and 4-methacrylamidosalicylic acid of 93.7 mol % composition have been synthesized, and their interaction with terbium and gadolinium ions has been investigated to fabricate luminescent probes promising for their visualization in biomedical research. It has been shown that, in aqueous solutions in the copolymer concentration range 0.15–1.7 mg mL–1 and at the ratio [Tb3+]/[COO–] = 1, water-soluble luminescent metal polymer complexes with a luminescence lifetime of 823 µs are formed. When Tb3+ ions are partially replaced in the complex by Gd3+ ions, bimetallic complexes with intense luminescence are formed.

Study on the adsorption of lanthanum ion imprinted on SBA-15/Y

The lanthanum ion imprinted polymer (La-IIP/SBA-15/Y) was successfully synthesized by the surface ion imprinting method. Using La-IIP/SBA-15/Y as the adsorbent to adsorb lanthanum ions, the overall empirical conditions were optimized, and the best exploratory conditions were finally found. The pH of the solution was 2; the adsorption equilibrium was reached in 60 min and the saturated adsorption capacity was 562.95 mg/g La-IIP/SBA-15/Y adsorbed gadolinium ions in the study of its adsorption process and found that it conforms to the Langmuir isotherm adsorption model, and the adsorption reaction is a spontaneous reaction, and it also conforms to the quasi-second-order kinetic model. The selectivity of the adsorbent was explored experimentally, and the results showed that La-IIP/SBA-15/Y has good selectivity, and experimental elution and regeneration performance. The best elution effect is 2 mol/L hydrochloric acid. La-IIP/SBA-15/Y has good stability and can be reused.

Using ELP Repeats as a Scaffold for De Novo Construction of Gadolinium-Binding Domains within Multifunctional Recombinant Proteins for Targeted Delivery of Gadolinium to Tumour Cells.

Three artificial proteins that bind the gadolinium ion (Gd3+) with tumour-specific ligands were de novo engineered and tested as candidate drugs for binary radiotherapy (BRT) and contrast agents for magnetic resonance imaging (MRI). Gd3+-binding modules were derived from calmodulin. They were joined with elastin-like polypeptide (ELP) repeats from human elastin to form the four-centre Gd3+-binding domain (4MBS-domain) that further was combined with F3 peptide (a ligand of nucleolin, a tumour marker) to form the F3-W4 block. The F3-W4 block was taken alone (E2-13W4 protein), as two repeats (E1-W8) and as three repeats (E1-W12). Each protein was supplemented with three copies of the RGD motif (a ligand of integrin αvβ3) and green fluorescent protein (GFP). In contrast to Magnevist (a Gd-containing contrast agent), the proteins exhibited three to four times higher accumulation in U87MG glioma and A375 melanoma cell lines than in normal fibroblasts. The proteins remained for >24 h in tumours induced by Ca755 adenocarcinoma in C57BL/6 mice. They exhibited stability towards blood proteases and only accumulated in the liver and kidney. The technological advantages of using the engineered proteins as a basis for developing efficient and non-toxic agents for early diagnosis of tumours by MRI as well as part of BRT were demonstrated.

Chemisorption of gadolinium ions on 2D-graphitic carbon nitride nanosheet for enhanced solid-state supercapacitor performance

Thiswork reveals a facile synthesis of gadolinium ions adsorbed 2D-graphitic carbon nitride nanosheets (Gd3+/2D-gCN NSs) via a chemical-adsorption method for supercapacitor electrode materials. The structural, microstructural, and electrochemical properties ofGd3+/2D-gCN NSs and pristine 2D-gCN NSs are ascertained.The calculated capacitance for Gd3+/2D-gCN NSs is almost three times higher than the pristine one. The Nyquist and Bode plots exhibit thecapacitancemechanism.Gd+intercalation between the electrical double layers of adjacent 2D-gCN nanosheets increase the Van der Waals gap, which enhances it's specific capacitance. There is almost 100% retention of capacitance for Gd3+/2D-gCN NSs based device over 1000thcycle.

Highly Luminescent and Multifunctional Zero‐Dimensional Cesium Lanthanide Chloride (Cs3LnCl6) Colloidal Nanocrystals

AbstractHerein, the synthesis of novel, highly luminescent, and nearly monodisperse zero‐dimensional (0D) cesium lanthanide chloride (Cs3LnCl6; Ln = Y, Ce, Gd, Er, Tm, Yb) colloidal nanocrystals (NCs) is reported for the first time. The Cs3LnCl6 NCs are synthesized using a heating‐up method and exhibit highly uniform size and shape. The monoclinic‐phase Cs3LnCl6 NCs contain completely isolated [LnCl6]3− octahedral units, resulting in 0D ternary metal halide structures. Therefore, these NCs exhibit deep‐blue photoluminescence under ultraviolet excitation, and this photoluminescence can be tuned by changing the lanthanide cations within the [LnCl6]3− octahedral units. High photoluminescence quantum yields of up to 60% and 90% are observed for the Cs3YbCl6 and Cs3YCl6 NCs, respectively, at room temperature and under ambient conditions. The Cs3LnCl6 NCs exhibit characteristic optical and magnetic properties owing to the f‐orbitals of the lanthanide elements. For example, near‐infrared‐to‐visible upconversion luminescence appears when Cs3LnCl6 NCs are doped with Er3+ and Yb3+ ions. In addition, the Cs3GdCl6 NCs demonstrate paramagnetic properties owing to the unpaired electrons within the f‐orbitals of the trivalent gadolinium ions. This study provides guidance for the rational design and synthesis of novel lanthanide‐based 0D metal halide NCs, which can potentially be used as highly efficient, multifunctional NC emitters.

Solution-combustion synthesized highly luminescent CaTiO3:Gd2O3:Eu3+ perovskite nanophosphors for WLED applications

A series of Ca (1- x - y ) TiO 3 : x Gd 3+ , y Eu 3+ perovskite nanophosphors were synthesized by the solution combustion employing metal-citrate complexation method. The luminescence enhancement of seven times and the color purity of 97.4% were observed when 5 mol% of Gd 3+ ions were substituted in the Ca 0.93 TiO 3 :0.07Eu 3+ phosphor. The occupancy of Gd 3+ and Eu 3+ ions at Ca 2+ sites were detected by Rietveld refinements and XPS spectroscopy. The characteristic binding energy peaks of Europium and Gadolinium ions evidenced their 3+ oxidation state. Raman shifts observed for these phosphors affirmed the phase purity and the appearance of localized vibrational modes at 803 cm −1 signifying the substitution of rare earth ions in the crystal. The TEM analysis confirmed a high degree of crystallinity. The single exponential nature of the luminescence decay curves vindicated the substitution of the activator ions at a unique site. The thermal activation energy of 0.31 eV obtained for Ca 0.88 Gd 0.05 TiO 3 :0.07Eu 3+ suggested an appreciable stability against thermal quenching due to the cross-over process. The color parameters, luminescence lifetime, Judd–Ofelt parameters and radiative properties have been fairly discussed. • Ca (1-x-y) TiO 3 :xGd 3+ , yEu 3+ nanophosphors were synthesized by solution combustion synthesis. • The optimum doping of Gd 3+ ions in Ca 0.93 TiO 3 :0.07Eu 3+ enhanced luminescence seven times. • The increase in the local asymmetry was denoted by color purity of 97.4% and enhancement of Judd–Ofelt parameter, Ω 2 . • The occupancy of dopants at Ca 2+ sites were detected by Rietveld refinements and XPS spectroscopy. • Raman shifts observed for these phosphors affirmed the phase purity.

DFT, MD simulations and experimental analysis of adsorptive complexation and isotope separation of gadolinium ion with macrocyclic crown ether embedded polymeric resin

Di-benzo-18-crown-6 ether (DB18C6) functionalized polymethyl acrylic acid (PMA) resin was synthesized after screening by employing density functional theory (DFT) and molecular dynamics (MD) simulations for the enrichment of gadolinium isotopes, Gd-155 and Gd-157. Batch adsorption and column chromatography studies were performed at various pH, gadolinium ion concentration and temperatures to check its efficacy and validation of theoretical approach. The adsorption capacity of gadolinium ion with the PMADB18C6 resin was found to be quite modest with a value of 1.128 mg/g. Both MD simulations and adsorption experiments confirm the Temkin type of adsorption isotherm. The positive entropy change along with the positive enthalpy change indicates that sorption of the Gd3+ ion with PMADB18C6 is entropy driven process. From the chromatography experiments, the lighter isotope (Gd-155) is seen to be depleted in the breakthrough volume samples which specify that the resin phase is depleted with heavier isotope (e.g Gd-160) contrast to natural Gd composition. The separation coefficient (ε) for Gd155/158, Gd156/158, Gd157/158, Gd155/160 and Gd157/160 isotopic pairs were found to be 1.67 × 10−3, 2.65 × 10−3, 5.40 × 10−4, 3.18 × 10−3 and 1.87 × 10−3 respectively. The experimental isotopic separation factor corroborates the DFT findings. Further, both DFT and MD simulations confirm the experimentally observed endothermic complexation of Gd3+ ion with PMADB18C6 resin. The present findings employing combined DFT, MD simulations and experimental approaches are expected to benefit in the fundamental understanding of molecular complexation based isotope separation and design and development of future gadolinium isotopic enrichment technologies using chemical exchange methods.

Biopolymer mixture-entrapped modified graphene oxide for sustainable treatment of heavy metal contaminated real surface water

The surface of graphene oxide (GO) features highly reactive carboxyl, epoxy, and hydroxyl groups; however, it cannot remove negatively charged species such as anion metals. Gadolinium (Gd) ions interact strongly with anionic species such as arsenic. The incorporation of gadolinium oxide to GO facilitates the removal of anion and cation heavy metals. However, the product was practically infeasible because to the thin, friable, and light flakes. To address these flaws, a polymer combination (Sodium Alginate (SA) and Carboxymethyl Cellulose (CMC)) was employed to bind GO–Gd2O3 into granules, the ability of which was verified to adsorb Cr(III), Pb(II), and As(V). The effective operating pH, dose, and temperature were 4.0, 1.4 g/L, and 298 K, respectively. Cr(III), Pb(II), and As(V) all had adsorption capabilities of 29.16, 158.73, and 36.77 mg/g, demonstrating gGO–Gd2O3 as effective granules for heavy metals removal from complex aquatic environments. According to the thermodynamic data, Cr(III) and As(V) adsorptions are endothermic, but Pb(II) adsorption is exothermic. The probable sorption mechanism was thoroughly discussed. The viability of produced materials was assessed by investigating their re-usability and use in real surface water.

A Molecule Having 13 Unpaired Electrons: Magnetic Property of a Gadolinium(III) Complex Coordinated with Six Nitronyl Nitroxide Radicals.

A gadolinium(III) complex coordinated with six nitronyl nitroxide radicals showed intriguing temperature-dependent changes in magnetic susceptibilities. The gadolinium(III) ion in the complex is pseudo-eight-coordinated by three singlet-ground-state diradical anion species based on nitronyl nitroxide radicals. The magnetic susceptibility (χpT) of the gadolinium(III) complex at 298 K, whose value corresponded to that of a system with 13 unpaired electrons (seven-spin system), decreased upon a lowering of the temperature to 11 K but increased upon a further lowering of the temperature. Finally, the χpT value at 2 K was found to be higher than that at room temperature. The temperature-dependent magnetic behavior could be explained by a structural change in the diradical anion ligand due to its flexibility.

Structural characterization of interfaces in silica core-alumina shell microspheres by solid-state NMR spectroscopy

Atomic-scale description of surfaces and interfaces in core-shell aluminosilicate materials is not fully elucidated, partially due to their amorphous character and complex mechanisms that govern their properties. In this paper, new insights into nanostructured core-shell aluminosilicates have been demonstrated, by using different solid-state NMR methods, i.e 29Si, 29Si cross-polarization (CP), 27Al, 27Al triple-quantum (3Q), and 1H–27Al heteronuclear correlation (HETCOR) MAS NMR. For this purpose, nanostructured silica core-alumina shell microspheres, undoped and doped with gadolinium ions respectively, obtained by a chemical synthesis based on the Stöber method for the silica core and electrostatic attraction for developing the alumina shell were studied. As a result, a new alumino-silicate layer formation was proved at the interface between silica core, where aluminum diffuses, on small scale, in the silica network, and alumina shell, where silicon ions migrate, on a larger scale, in the alumina network, leading to a stable core-shell structure. Moreover, this process is accompanied by significant local structural changes in the transition zone, particularly at the aluminum neighborhood, which is quite well understood now, with the power of solid-state NMR spectroscopy.

Surface modification of ball clay minerals with gamma irradiation polymerization for removal of cerium and gadolinium ions from aqueous phase

Surface modification of ball clay was produced by gamma irradiation of a mixture containing ball clay (BC), acrylic acid (AA), phosphoric acid (PA), and N,N`-methylenebisacrylamide (DAM) solution to produce a composite sorbent (BC-AA-PA). Both BC and BC-AA-PA composite were characterized using SEM, FT-IR, XRD, and XRF. Comparative evaluation of both materials for the sorption of gadolinium and cerium ions was explored. The outcomes exposed that the removal percentage enhanced from 38.2% to 91% and from 24.9% to 88% for gadolinium and cerium ions by BC and BC-AA-PA, respectively. The proposed sorption mechanism illustrated that the sorption occurs by an ion exchange process. Sorption kinetics, equilibrium isotherm, and desorption studies were conducted. The sorption obeyed the pseudo-second-order model and Langmuir isotherm model. The comparison of sorption capacity of BC-AA-PA with other sorbents in the literature indicated that BC-AA-PA has a much higher sorption capacity than many sorbents (1.085 and 0.907 mmol/g for Gd3+ and Ce3+, respectively). Desorption of gadolinium and cerium ions from BC-AA-PA was investigated; the results certified that 0.1 M HNO3 is the best eluent with a percentage of 99.99 and 92% for Ce3+ and Gd3+, respectively, and the BC-AA-PA can be applied for further sorption processes. Hence, BC-AA-PA composite sorbent is recommended for the sorption of lanthanides from the liquid phase.