Explore the vast range of titles available.

Organometallic compounds are increasingly recognized as promising anticancer and antibiotic drug candidates. Among the transition metal ions investigated for these purposes, rhenium occupies a special role. Its tri- and dicarbonyl complexes, in particular, attract continuous attention due to their relative ease of preparation, stability and unique photophysical and luminescent properties that allow the combination of diagnostic and therapeutic purposes, thereby permitting, e.g., molecules to be tracked within cells. In this review, we discuss the anticancer and antibiotic properties of rhenium tri- and dicarbonyl complexes described in the last seven years, mainly in terms of their structural variations and in vitro efficacy. Given the abundant literature available, the focus is initially directed on tricarbonyl complexes of rhenium. Dicarbonyl species of the metal ion, which are slowly gaining momentum, are discussed in the second part in terms of future perspective for the possible developments in the field.

Rhenium ( 186 Re) Obisbemeda ( 186 RNL), chelated- 186 Re encapsulated in nanoliposomes and delivered to brain tumors via convection enhanced delivery (CED), was evaluated in a Phase 1 dose escalation trial (NCT01906385). The primary objective was to determine the maximum tolerated dose (MTD). Secondary objectives included safety and tolerability, dose distribution, the overall response rate (ORR), disease-specific progression-free survival (PFS), and overall survival (OS). 21 patients received up to 22.3 mCi 186 RNL over 6 dosing cohorts. Most adverse events (AEs) were unrelated to 186 RNL and the MTD was not reached. Although not predefined outcomes, the mOS and mPFS were 11 and 4 months, respectively, and found to correlate with radiation absorbed dose to the tumor and percent tumor treated. When dichotomized by absorbed dose of 100 Gy, the mOS and mPFS were 17 months and 6 months, respectively, for >100 Gy, compared to 6 (mOS) and 2 (mPFS) months, respectively, for <100 Gy. For ORR, 57.1% exhibited stable disease (SD), 4.8% partial response, and 38.1% progressive disease. Overall, patients received radiation absorbed doses without significant toxicity higher than possible with external beam radiation therapy (EBRT) and demonstrated mOS beyond standard of care for recurrent glioblastoma (~8 months). Radiotherapy is a key component of glioblastoma therapy, however, difficulties in delivering high doses to tumours cells while preserving healthy tissues risks limits its success. Here, the authors report a phase I dose escalation study investigating convection enhanced delivery of Rhenium (186Re) Obisbemeda (186RNL), chelated-186Re encapsulated in nanoliposomes, in patients with recurrent, high-grade malignant glioma.

Rhenium (Re) is widely used in the diagnosis and treatment of cancer due to its unique physical and chemical properties. Re has more valence electrons in its outer shell, allowing it to exist in a variety of oxidation states and to form different geometric configurations with many different ligands. The luminescence properties, lipophilicity, and cytotoxicity of complexes can be adjusted by changing the ligand of Re. This article mainly reviews the development of radionuclide 188Re in radiotherapy and some innovative applications of Re as well as the different therapeutic approaches and imaging techniques used in cancer therapy. In addition, the current application and future challenges and opportunities of Re are also discussed.

Based on the first-principles calculations, the electronic structure and optical properties of the Mo-doped monolayer rhenium disulfide (ReS₂) model are calculated, and the system stability, bond length, charge difference density, band structure, photoabsorption coefficient, system stability, and reflectivity are analyzed. The calculation results show that doping changes the structural stability of the system, which gradually decreases with an increasing concentration of doping. The calculation of band structure and density of states indicated that the band gap value of the system decreases continuously to 0 with increasing doping concentration, while the average charge population of atoms at doping sites keeps increasing with the better electron-losing ability of atoms. Compared with the intrinsic monolayer ReS₂, the peak of systemic reflectivity at different doping concentrations has corresponding degrees of redshift in a certain wavelength range, as demonstrated by the optical properties.

SummaryThe rhenium(I)-diselenoether complex (Re-diSe) is a rhenium tricarbonyl-based drug chelated by a diselenoether ligand. In this work, we compared its inhibitory effects on the hormone-independent MDA-MB231cancer line and other different cancer cell lines after an exposure time of 72 h by MTT assays. The sensitivity of MDA-MB231 was in the same range than the hormone-dependent MCF-7 breast cancer, the PC-3 prostate and HT-29 colon cancer cells, while the A549 lung and the HeLa uterine cancer cells were less sensitive. We compared the inhibitory effects of Re-diSe and of its diselenide ligand (di-Se) on MDA-MB231 and a normal HEK-293 human embryonic cell line, after 72 h and 120 h of exposure. The cytotoxicity was also studied by flow cytometry using ethidium bromide assays, as well as the effects on the ROS production by DFCA-test, while the levels of TGF-β1, VEGF-A, IGF-1 were addressed by ELISA tests. The dose required to inhibit 50% of the proliferation (IC50) of MDA-MB231 breast cancer cells decreased with the time of exposure to 120 h, while the free ligand (di-Se) was found poorly active, demonstrating the important role of Re in this Re-diSe combination. The cytotoxic effects of Re-diSe were highly selective for cancer cells, with a significant increase of the number of dead cancer cells at 5 μM for an exposure time of 120 h, while normal cells were not affected. A remarkable and significant decrease of the production of ROS together with a decrease of VEGF-A, TGF-β1, and IGF-1 by the cancer cells were also observed when cancer cells were exposed to Re-diSe.

Current tumor diagnostics rely on fluorodeoxyglucose (FDG)-PET imaging, but FDG’s short half-life and high cost limit its widespread use. Infrared (IR) probes are emerging as non-radioactive alternatives to conventional tracers for tissue section and other in vitro imaging applications. Because cells and tissues are relatively free of absorption peaks between 1800 and 2200 cm−1, metal-carbonyl complexes, especially cyclopentadienylrhenium(I) tricarbonyl (Cp[Re(CO)3]) derivatives, absorb strongly in this window and provide robust platforms for bioconjugation. Furthermore, Cp[Re(CO)3] fragments can be introduced into organic substrates via an elegant three-component reaction that simultaneously forges the cyclopentadienyl-metal and cyclopentadienyl-substituent bonds. As a result, the functionalized half-sandwich complex is obtained in a single step without any special handling issues. We have therefore properly modified a glucose molecule with that complex and developed a novel glucoconjugated Cp[Re(CO)3] probe that enables IR-based visualization of diseased cells at 2100 cm−1, offering a non-invasive, non-radioactive histological tool and a promising basis for future medical imaging devices.

Despite improvements in the 5-year survival rate to over 80% in cancers, such as Hodgkin lymphoma and testicular cancer, more aggressive tumors including pancreatic and brain cancer still have extremely low survival rates. The establishment of chemoresistance, responsible for the reduction in treatment efficiency and cancer relapse, is one possible explanation for this setback. Metal-based compounds, a class of anticancer drugs, are largely used in the treatment of cancer. Herein, we will review the use of metal-based small molecules in chemotherapy, focusing on recent studies, and we will discuss how new nonplatinum-based agents are prompting scientists to increase drug specificity to overcome chemoresistance in cancer cells.

The paper deals with the study of rhenium recovery by AMR anionite from model high-acidic sulfuric solution as well as its desorption by ammonia solution in column experiments. Total dynamic exchange capacity was calculated. Experimental data were processed using the Thomas, Yoon-Nelson and Bed Depth Service Time models, basic parameters were calculated. It was found that total dynamic exchange capacity calculated by Thomas fit was the closest to the experimental value. Rhenium desorption was examined using ammonia solution. Rhenium recovery degree and concentration factor were calculated. The elution curve featured a clear peak that allows producing eluate with high rhenium concentration. The presented results may be used when designing technologies for rhenium sorption from different process solutions and during recycling rhenium-containing alloy wastes.

Antimicrobial resistance (AMR) poses a critical global health threat by rendering existing antibiotics ineffective against infections, leading to increased mortality, prolonged illnesses, and higher healthcare costs. Developing new antibiotics is essential to combat resistant pathogens, safeguard modern medical procedures, and prevent a return to a pre-antibiotic era where common infections become untreatable. We report a series of chiral tricarbonyl rhenium(I) complexes incorporating enantiopure pinene-substituted bipyridine ligands (L#) of the general formula fac-[Re(CO)3L#X] and fac-[Re(CO)3L#Py]+ (where X = Cl or Br and Py = pyridine). These complexes were isolated as mixtures of two diastereomers, characterized by standard techniques, and evaluated for cytotoxic activity against methicillin-resistant and methicillin-sensitive Staphylococcus aureus (MRSA and MSSA). The results revealed notable antibacterial efficacy (MIC = 1.6 μM), reflected in high therapeutic indices (Ti > 10). In contrast, analogous complexes bearing non-chiral 2,2′-bipyridine ligands exhibited no activity, underscoring the critical role of chirality in modulating biological interactions at the molecular level. These findings highlight the potential of chiral Re(I) complexes as promising scaffolds for the development of more potent and selective antibacterial agents.

The quest to create superhard materials rarely strays from the use of high-pressure synthetic methods, which typically require gigapascals of applied pressure. We report that rhenium diboride (ReB₂), synthesized in bulk quantities via arc-melting under ambient pressure, rivals materials produced with high-pressure methods. Microindentation measurements on ReB₂ indicated an average hardness of 48 gigapascals under an applied load of 0.49 newton, and scratch marks left on a diamond surface confirmed its superhard nature. Its incompressibility along the c axis was equal in magnitude to the linear incompressibility of diamond. In situ high-pressure x-ray diffraction measurements yielded a bulk modulus of 360 gigapascals, and radial diffraction indicated that ReB₂ is able to support a remarkably high differential stress. This combination of properties suggests that this material may find applications in cutting when the formation of carbides prevents the use of traditional materials such as diamond.