A Gadolinium(III) Complex Based on the Thymine Nucleobase with Properties Suitable for Magnetic Resonance Imaging

Fluorescently Labeled Gadolinium Ferrate/Trigadolinium Pentairon(III) Oxide Nanoparticles: Synthesis, Characterization, In Vivo Biodistribution, and Application for Visualization of Myocardial Ischemia-Reperfusion Injury

Various gadolinium compounds have been proposed as contrasting agents for magnetic resonance imaging (MRI). In this study, we suggested a new synthesis method of gadolinium ferrate/trigadolinium pentairon(III) oxide nanoparticles (GF/TPO NPs). The specific surface area of gadolinium ferrate (GdFeO₃) and trigadolinium pentairon(III) oxide (Gd₃Fe₅O₁₂) nanoparticles was equal to 42 and 66 m²/g, respectively. The X-ray diffraction analysis confirmed that the synthesized substances were GdFeO₃ and Gd₃Fe₅O₁₂. The gadolinium content in the samples was close to the theoretically calculated value. The free gadolinium content was negligible. Biodistribution of the GF/TPO NPs was studied in rats by fluorescent imaging and Fe²⁺/Fe³⁺ quantification demonstrating predominant accumulation in such organs as lung, kidney, and liver. We showed in the in vivo rat model of myocardial ischemia–reperfusion injury that GF/TPO NPs are able to target the area of myocardial infarction as evidenced by the significantly greater level of fluorescence. In perspective, the use of fluorescently labeled GF/TPO NPs in multimodal imaging may provide basis for high-resolution 3D reconstruction of the infarcted heart, thereby serving as unique theranostic platform.

Metal Complexes in Diagnosis and Therapy

The use of metal complexes for health and healing has been in use for over the last several millennia and perhaps longer [...].

Molecular Self-Assembly of an Unusual Dinuclear Ruthenium(III) Complex Based on the Nucleobase Guanine

The study of crystal structures based on complexes containing purine nucleobases is a significant research subject, mainly regarding the diagnosis and treatment of some diseases and the investigation of genetic mutations and biochemical structures in life sciences. We have obtained and characterized a new dinuclear ruthenium(III) complex based on guanine with the formula [{Ru(µ-Cl)(µ-gua)}2Cl4]·2H2O (1) (gua = guanine). 1 was characterized by means of Fourier transform infrared spectroscopy (FT–IR), scanning electron microscopy and energy dispersive X-ray analysis (SEM–EDX), single-crystal X-ray diffraction (XRD), Hirshfeld surface analysis and cyclic voltammetry (CV). The study of its electrochemical properties allowed us to investigate the presence of guanine molecules when linked to the ruthenium(III) ion in 1. The well-resolved voltammetric response together with the reliability and stability achieved through 1 could provide a step forward to developing new ruthenium-based platforms, devices and modified electrodes adequate to study this purine nucleobase.

One-Dimensional Gadolinium (III) Complexes Based on Alpha- and Beta-Amino Acids Exhibiting Field-Induced Slow Relaxation of Magnetization

Gadolinium (III) complexes exhibiting slow relaxation of magnetization are uncommon and have been much less studied than other compounds based on anisotropic lanthanide (III) ions. We prepared two one-dimensional gadolinium (III) complexes based on α-glycine (gly) and β-alanine (β-ala) amino acids, with the formula {[Gd2(gly)6(H2O)4](ClO4)6·5H2O}n (1) and {[Gd2(β-ala)6(H2O)4](ClO4)6·H2O}n (2), which were magneto-structurally characterized. Compounds 1 and 2 crystallize in the triclinic system (space group Pī). In complex 1, two Gd (III) ions are eight-coordinate and bound to six oxygen atoms from six gly ligands and two oxygen atoms from two water molecules, the metal ions showing different geometries (bicapped trigonal prism and square antiprism). In complex 2, two Gd (III) ions are nine-coordinate and bound to seven oxygen atoms from six β-ala ligands and two oxygen atoms from two water molecules in the same geometry (capped square antiprism). Variable-temperature dc magnetic susceptibility measurements performed on microcrystalline samples of 1 and 2 show similar magnetic behavior for both compounds, with antiferromagnetic coupling between the Gd (III) ions connected through carboxylate groups. Ac magnetic susceptibility measurements reveal slow relaxation of magnetization in the presence of an external dc field in both compounds, hence indicating the occurrence of the field-induced single-molecule magnet (SMM) phenomenon in both 1 and 2.

Hexahalorhenate(iv) salts of protonated ciprofloxacin: antibiotic-based single-ion magnets

In the crystal lattice of two novel ReIV compounds, the paramagnetic [ReCl6]2− and [ReBr6]2− anions are well separated from each other through two protonated forms of the antibiotic ciprofloxacin. These compounds behave as single-ion magnets (SIMs).