188Re(V) Nitrido Radiopharmaceuticals for Radionuclide Therapy

Design anticancer potential of Zn(II)isoleucinedithiocarbamate complex on MCF-7 cell lines: synthesis, characterization, molecular docking, molecular dynamic, ADMET, and in-vitro studies

Cisplatin is a cancer medication widely used today, but it still poses some problems due to its toxic properties in the body. To overcome this issue, a new complex has been developed as a potential anticancer drug prospect by minimizing its toxic consequences. A novel Zn(II)IleDTC complex containing isoleucine dithiocarbamate ligands has been produced and analyzed using a range of analytical and spectroscopic methods. The Zn(II) IleDTC complex were characterized using various methods, including UV-Vis spectroscopy, FT-IR, determination of melting point, conductivity, and HOMO-LUMO analysis. Furthermore, computational NMR spectrum analysis was conducted in this study. Molecular docking studies was conducted to evaluate the potential of Zn(II) isoleucine dithiocarbamate as an HIF1 inhibitor. The results showed that the Zn complex exhibited a good docking score of -6.6 and formed hydrogen bonds with ARG 17, VAL264, and GLU15, alkyl bonds with TRP27 and LEU32, and Pi-Alkyl bonds with PRO41 and ARG44. This suggests that the Zn(II) isoleucine dithiocarbamate complex could be a promising candidate for cancer treatment with potential HIF1 inhibition properties. To assess the dynamic stability and efficacy of protein-ligand interactions over time, molecular dynamics simulations was conducted for both individual proteins and protein complexes. The cytotoxicity evaluation of Zn(II) isoleucine dithiocarbamate against MCF-7 cells obtained an IC50 value of 362.70 µg/mL indicating moderate cytotoxicity and morphological changes of cancer cells causing cancer cells to undergo apoptosis. The Zn(II) isoleucine dithiocarbamate complex may have promising potential as an anticancer compound due to its significant inhibitory effect on the breast cancer cell line (MCF7). According to the ADMET study, the complex exhibits drug-like characteristics with low toxicity, further supporting its potential as a viable drug candidate.

Development and Evaluation of the Magnetic Properties of a New Manganese (II) Complex: A Potential MRI Contrast Agent

Magnetic resonance imaging (MRI) is a non-invasive powerful modern clinical technique that is extensively used for the high-resolution imaging of soft tissues. To obtain high-definition pictures of tissues or of the whole organism this technique is enhanced by the use of contrast agents. Gadolinium-based contrast agents have an excellent safety profile. However, over the last two decades, some specific concerns have surfaced. Mn(II) has different favorable physicochemical characteristics and a good toxicity profile, which makes it a good alternative to the Gd(III)-based MRI contrast agents currently used in clinics. Mn(II)-disubstituted symmetrical complexes containing dithiocarbamates ligands were prepared under a nitrogen atmosphere. The magnetic measurements on Mn complexes were carried out with MRI phantom measurements at 1.5 T with a clinical magnetic resonance. Relaxivity values, contrast, and stability were evaluated by appropriate sequences. Studies conducted to evaluate the properties of paramagnetic imaging in water using a clinical magnetic resonance showed that the contrast, produced by the complex [Mn(II)(L')₂] × 2H₂O (L' = 1.4-dioxa-8-azaspiro[4.5]decane-8-carbodithioate), is comparable to that produced by gadolinium complexes currently used in medicine as a paramagnetic contrast agent.

Anticancer potential of Cu(II)prolinedithiocarbamate complex: design, synthesis, spectroscopy, molecular docking, molecular dynamic, ADMET, and in-vitro studies

Breast cancer continues to be a major health issue for women all over the world. Cancer medications like cisplatin, which are widely used, still have negative side effects. The novel complex was created as a potential anticancer medication candidate that is both effective and safe, with few side effects. The Cu(II) complex using the prolinedithiocarbamate ligands was synthesized in situ. The Cu(II) complexes Characterization by UV-Vis, FT-IR spectroscopy and melting point determination, conductivity, and HOMO-LUMO were studied. Computational NMR spectrum analysis was performed. The interaction of Cu(II)prolineditiocarbamate complex with cancer cell target protein (MCF-7) was confirmed by molecular docking and molecular dynamic. The pharmacokinetic/ADMET properties were also performed on the complex. Results of the cytotoxic complex test against cancer cells (MCF-7) undergoing apoptosis with an IC50 value of 13.64 µg/mL showed high anticancer activity in MCF-7 cancer cells. The in-vivo data for Cu(II)prolineditiocarbamate complex was predicted using the Protox online tool with an LD50 value of 2500 mg/kg and belonging to the GHS toxicity class 5, which means the compound has a low acute toxicity effect. The Cu(II) prolineitiocarbamate complex may pave the way for the development of essential metal-based chemotherapy for the treatment of breast cancer.Communicated by Ramaswamy H. Sarma.

Rhenium Radioisotopes for Medicine, a Focus on Production and Applications

In recent decades, the use of alpha; pure beta; or beta/gamma emitters in oncology, endocrinology, and interventional cardiology rheumatology, has proved to be an important alternative to the most common therapeutic regimens. Among radionuclides used for therapy in nuclear medicine, two rhenium radioisotopes are of particular relevance: rhenium-186 and rhenium-188. The first is routinely produced in nuclear reactors by direct neutron activation of rhenium-186 via 185Re(n,γ)186Re nuclear reaction. Rhenium-188 is produced by the decay of the parent tungsten-188. Separation of rhenium-188 is mainly performed using a chromatographic 188W/188Re generator in which tungsten-188 is adsorbed on the alumina column, similar to the 99Mo/99mTc generator system, and the radionuclide eluted in saline solution. The application of rhenium-186 and rhenium-188 depends on their specific activity. Rhenium-186 is produced in low specific activity and is mainly used for labeling particles or diphosphonates for bone pain palliation. Whereas, rhenium-188 of high specific activity can be used for labeling peptides or bioactive molecules. One of the advantages of rhenium is its chemical similarity with technetium. So, diagnostic technetium analogs labeled with radiorhenium can be developed for therapeutic applications. Clinical trials promoting the use of 186/188Re-radiopharmaceuticals is, in particular, are discussed.

Bifunctional chelators for radiorhenium: past, present and future outlook

Targeted radionuclide therapy (TRNT) is an ever-expanding field of nuclear medicine that provides a personalised approach to cancer treatment while limiting toxicity to normal tissues. It involves the radiolabelling of a biological targeting vector with an appropriate therapeutic radionuclide, often facilitated by the use of a bifunctional chelator (BFC) to stably link the two entities. The radioisotopes of rhenium, 186Re (t 1/2 = 90 h, 1.07 MeV β-, 137 keV γ (9%)) and 188Re (t 1/2 = 16.9 h, 2.12 MeV β-, 155 keV γ (15%)), are particularly attractive for radiotherapy because of their convenient and high-abundance β--particle emissions as well as their imageable γ-emissions and chemical similarity to technetium. As a transition metal element with multiple oxidation states and coordination numbers accessible for complexation, there is great opportunity available when it comes to developing novel BFCs for rhenium. The purpose of this review is to provide a recap on some of the past successes and failings, as well as show some more current efforts in the design of BFCs for 186/188Re. Future use of these radionuclides for radiotherapy depends on their cost-effective availability and this will also be discussed. Finally, bioconjugation strategies for radiolabelling biomolecules with 186/188Re will be touched upon.

Synthesis and Characterization of Manganese Dithiocarbamate Complexes: New Evidence of Dioxygen Activation

(1) Background: Metal dithiocarbamate compounds have long been the subject of research due to their ease of formation, excellent properties and potential applications. However, manganese complexes with dithiocarbamates, to our knowledge, have never been used for medical imaging applications. With the aim of developing a new class of mononuclear manganese(II)-based agents for molecular imaging applications, we performed a specific investigation into the synthesis of mononuclear bis-substituted Mn(II) complexes with dithiocarbamate ligands. (2) Methods: Synthesis in either open or inert atmosphere at different Mn(II) to diethyldithiocarbamate molar ratios were performed and the products characterized by IR, EA, ESI-MS and XRD analysis. (3) Results: We found that only under oxygen-free atmospheric conditions the Mn(II) complex MnL₂, where L = diethyldithiocarbamate ligand, is obtained, which was further observed to react with dioxygen in the solid state to form the intermediate superoxo Mn(III) complex [MnL₂(η²-O₂)]. The existence of the superoxo complex was revealed by mass spectroscopy, and this species was interpreted as an intermediate step in the reaction that led the bis-substituted Mn(II) complex, MnL₂, to transform into the tris-substituted Mn(III) complex, MnL₃. A similar result was found with the ligand L’ (= bis(N-ethoxyethyl)dithiocarbamate). (4) Conclusions: We found that in open atmosphere and in aqueous solution, only manganese(III) diethyldithiocarbamate complexes can be prepared. We report here a new example of a small-molecule Mn(II) complex that efficiently activates dioxygen in the solid state through the formation of an intermediate superoxide adduct.

90Y/177Lu-DOTATOC: From Preclinical Studies to Application in Humans

The PRRT (Peptide Receptor Radionuclide Therapy) is a promising modality treatment for patients with inoperable or metastatic neuroendocrine tumors (NETs). Progression-free survival (PFS) and overall survival (OS) of these patients are favorably comparable with standard therapies. The protagonist in this type of therapy is a somatostatin-modified peptide fragment ([Tyr3] octreotide), equipped with a specific chelating system (DOTA) capable of creating a stable bond with β-emitting radionuclides, such as yttrium-90 and lutetium-177. In this review, covering twenty five years of literature, we describe the characteristics and performances of the two most used therapeutic radiopharmaceuticals for the NETs radio-treatment: [90Y]Y-DOTATOC and [177Lu]Lu-DOTATOC taking this opportunity to retrace the most significant results that have determined their success, promoting them from preclinical studies to application in humans.

Recent advances in the synthesis of (99mTechnetium) based radio-pharmaceuticals

Technetium radionuclide (99mTc) has excellent extent of disintegration properties and occupies a special place in the field of nuclear medicinal chemistry and other health disciplines. Current review describes recent approaches of synthesis in detailed ways for radio-pharmaceuticals of technetium which have been developed to treat and diagnose the biotic disorders. These technetium labeled radio-pharmaceuticals have been established to apply in the field of diagnostic nuclear medicine especially for imaging of different body parts such as brain, heart, kidney, bones and so on, through single photon emission computed tomography (SPECT) that is thought to be difficult to image such organs by using common X-ray and MRI (Magnetic Resonance Imaging) techniques. This review highlights and accounts an inclusive study on the various synthetic routes of technetium labeled radio-pharmaceuticals using ligands with various donor atoms such as carbon, nitrogen, sulphur, phosphorus etc. These compounds can be utilized as next generation radio-pharmaceuticals.

A Picture of Modern Tc-99m Radiopharmaceuticals: Production, Chemistry, and Applications in Molecular Imaging

Even today, techentium-99m represents the radionuclide of choice for diagnostic radio-imaging applications. Its peculiar physical and chemical properties make it particularly suitable for medical imaging. By the use of molecular probes and perfusion radiotracers, it provides rapid and non-invasive evaluation of the function, physiology, and/or pathology of organs. The versatile chemistry of technetium-99m, due to its multi-oxidation states, and, consequently, the ability to produce a variety of complexes with particular desired characteristics, are the major advantages of this medical radionuclide. The advances in technetium coordination chemistry over the last 20 years, in combination with recent advances in detector technologies and reconstruction algorithms, make SPECT’s spatial resolution comparable to that of PET, allowing 99mTc radiopharmaceuticals to have an important role in nuclear medicine and to be particularly suitable for molecular imaging. In this review the most efficient chemical methods, based on the modern concept of the 99mTc-metal fragment approach, applied to the development of technetium-99m radiopharmaceuticals for molecular imaging, are described. A specific paragraph is dedicated to the development of new 99mTc-based radiopharmaceuticals for prostate cancer.

Therapeutic Radiometals: Worldwide Scientific Literature Trend Analysis (2008⁻2018)

Academic journals have published a large number of papers in the therapeutic nuclear medicine (NM) research field in the last 10 years. Despite this, a literature analysis has never before been made to point out the research interest in therapeutic radionuclides (RNs). For this reason, the present study aims specifically to analyze the research output on therapeutic radiometals from 2008 to 2018, with intent to quantify and identify global trends in scientific literature and emphasize the interdisciplinary nature of this research field. The data search targeted conventional (¹³¹I, ⁹⁰Y, ¹⁷⁷Lu, ¹⁸⁸Re, ¹⁸⁶Re, ¹⁵³Sm, ⁸⁹Sr, ¹⁸⁶Er) and emergent (⁶⁷Cu, ⁴⁷Sc, ²²³Ra, ¹⁶⁶Ho, ¹⁶¹Tb, ¹⁴⁹Tb, ²¹²Pb/²¹²Bi, ²²⁵Ac, ²¹³Bi, ²¹¹At, ^117mSn) RNs. Starting from this time frame, authors have analyzed and interpreted this scientific trend quantitatively first, and qualitatively after.

Interdisciplinary Tasks in the Cyclotron Production of Radiometals for Medical Applications. The Case of 47Sc as Example

The growing number of cyclotrons of different sizes installed in the territory has given a strong impulse to the production of conventional and emerging radionuclides for medical applications. In particular, the great advantage of using medical cyclotrons is the possibility to produce on-site, when needed (on-demand), with medical radionuclides of interest encouraging the personalized medicine approach. Radiometals satisfy the ideal characteristics that radionuclides should have for routine employment in nuclear medicine, especially since they have a robust chemistry suitable to synthetize stable in vivo radiopharmaceuticals with high radiochemical yields. In this letter several interdisciplinary aspects involved in the radiometals cyclotron production cycle are summarized focusing the attention on cyclotron production facilities, target material, and chemical processing available for medical applications. As an example, the current status and recent development in the production of the theranostic radionuclide scandium-47 have been reported.

Monoclonal Antibodies Radiolabeling with Rhenium-188 for Radioimmunotherapy

Rhenium-188, obtained from an alumina-based tungsten-188/rhenium-188 generator, is actually considered a useful candidate for labeling biomolecules such as antibodies, antibody fragments, peptides, and DNAs for radiotherapy. There is a widespread interest in the availability of labeling procedures that allow obtaining ¹⁸⁸Re-labeled radiopharmaceuticals for various therapeutic applications, in particular for the rhenium attachment to tumor-specific monoclonal antibodies (Mo)Abs for immunotherapy. Different approaches have been developed in order to obtain ¹⁸⁸Re-radioimmunoconjugates in high radiochemical purity starting from the generator eluted [¹⁸⁸Re]ReO₄⁻. The aim of this paper is to provide a short overview on ¹⁸⁸Re-labeled (Mo)Abs, focusing in particular on the radiolabeling methods, quality control of radioimmunoconjugates, and their in vitro stability for radioimmunotherapy (RIT), with particular reference to the most important contributions published in literature in this topic.