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Chimia Dec 2020Due to its long half-life of 2.111×10 y, technetium, Tc, offers the excellent opportunity of combining fundamental and ' classical ' organometallic or coordination... (Review)
Review
Due to its long half-life of 2.111×10 y, technetium, Tc, offers the excellent opportunity of combining fundamental and ' classical ' organometallic or coordination chemistry with all methodologies of radiochemistry. Technetium chemistry is inspired by the applications of its short-lived metastable isomer Tc in molecular imaging and radiopharmacy. We present in this article examples about these contexts and the impact of purely basic oriented research on practical applications. This review shows how the chemistry of this element in the middle of the periodic system inspires the chemistry of neighboring elements such as rhenium. Reasons are given for the frequent observation that the chemistries of Tc and Tc are often not identical, compounds accessible for Tc, under certain conditions, are not accessible for Tc. The article emphasizes the importance of macroscopic technetium chemistry not only for research but also for advanced education in the general fields of radiochemistry.
Topics: Molecular Imaging; Radiochemistry; Radiopharmaceuticals; Rhenium; Technetium
PubMed: 33357288
DOI: 10.2533/chimia.2020.953 -
Molecules (Basel, Switzerland) Jul 2014Recent advances (during the 2007-2014 period) in the coordination and organometallic chemistry of compounds containing natural and artificially prepared radionuclides... (Review)
Review
Recent advances (during the 2007-2014 period) in the coordination and organometallic chemistry of compounds containing natural and artificially prepared radionuclides (actinides and technetium), are reviewed. Radioactive isotopes of naturally stable elements are not included for discussion in this work. Actinide and technetium complexes with O-, N-, N,O, N,S-, P-containing ligands, as well π-organometallics are discussed from the view point of their synthesis, properties, and main applications. On the basis of their properties, several mono-, bi-, tri-, tetra- or polydentate ligands have been designed for specific recognition of some particular radionuclides, and can be used in the processes of nuclear waste remediation, i.e., recycling of nuclear fuel and the separation of actinides and fission products from waste solutions or for analytical determination of actinides in solutions; actinide metal complexes are also usefulas catalysts forcoupling gaseous carbon monoxide,as well as antimicrobial and anti-fungi agents due to their biological activity. Radioactive labeling based on the short-lived metastable nuclide technetium-99m ((99m)Tc) for biomedical use as heart, lung, kidney, bone, brain, liver or cancer imaging agents is also discussed. Finally, the promising applications of technetium labeling of nanomaterials, with potential applications as drug transport and delivery vehicles, radiotherapeutic agents or radiotracers for monitoring metabolic pathways, are also described.
Topics: Actinoid Series Elements; Coordination Complexes; Elements, Radioactive; Ligands; Organometallic Compounds; Technetium
PubMed: 25061724
DOI: 10.3390/molecules190810755 -
Journal of Liposome Research 2015Porphyrin-lipid nanovesicles (PLN) have been developed with intrinsic capabilities as activatable multimodal photonic contrast agents. Radiolabeling of PLN encapsulating...
Porphyrin-lipid nanovesicles (PLN) have been developed with intrinsic capabilities as activatable multimodal photonic contrast agents. Radiolabeling of PLN encapsulating drugs could eventually be able to provide quantitative in vivo information for diagnosing and treating diseases. In this study, we developed (99m)Tc-labeled porphyrin-lipid nanovesicles ((99m)Tc-PLN) as a cargo-encapsulated formulation without significant impact on liposome integrity and encapsulation stability. 50 mM calcein was encapsulated into PLN by probe sonication. The size of the PLN was about 150 nm. The PLN were then reacted with (99m)Tc using SnCl2 dissolved in 1 mM HCl as a reducing agent and incubated for 10 min at 22 °C. The radiolabeling efficiency and stability of (99m)Tc-PLN were evaluated by instant thin-layer chromatography and low-pressure liquid chromatography (LPLC). (99m)Tc labeling was successful with a >92% labeling efficiency. LPLC showed that the liposomal elution peaks of the porphyrin-lipid and the calcein overlapped with the radioactivity elution peak of (99m)Tc-labeled PLN. The (99m)Tc-labeling procedure did not change the size of PLN. Encapsulated calcein remained inert inside PLN. Thus, this work lays out a simple and effective radiolabeling method using SnCl2 in HCl in the preparation of (99m)Tc-PLN.
Topics: Lipids; Nanostructures; Porphyrins; Technetium
PubMed: 24963601
DOI: 10.3109/08982104.2014.932379 -
International Journal of Nanomedicine 2018Nowadays, molecular imaging radiopharmaceuticals', nanoparticles', and/or small-molecule biomarkers' applications are increasing rapidly worldwide. Thus, researchers...
INTRODUCTION
Nowadays, molecular imaging radiopharmaceuticals', nanoparticles', and/or small-molecule biomarkers' applications are increasing rapidly worldwide. Thus, researchers focus on providing the novel, safe, and cost-effective ones.
MATERIALS AND METHODS
In the present experiment, technetium-99m (Tc)-labeled PEG-citrate dendrimer-G conjugated with glutamine (nanoconjugate) was designed and assessed as a novel tumor imaging probe both in vitro and in vivo. Nanoconjugate was synthesized and the synthesis was confirmed by Fourier transform infrared, proton nuclear magnetic resonance, liquid chromatography-mass spectrometry, dynamic light scattering, and static light scattering techniques. The toxicity was assessed by XTT and apoptosis and necrosis methods.
RESULTS
Radiochemical purity indicates that the anionic dendrimer has a very high potential to complex formation with Tc and is also very stable in the human serum in different times. Results from the imaging procedures showed potential ability of nanoconjugates to detect tumor site.
CONCLUSION
Suitable features of the anionic dendrimer show that it is a promising agent to improve nanoradiopharmaceuticals.
Topics: Animals; Dendrimers; Glutamine; Humans; In Vitro Techniques; Lung Neoplasms; Mice; Molecular Imaging; Nanoparticles; Radiopharmaceuticals; Technetium; Tissue Distribution; Tumor Cells, Cultured
PubMed: 30154653
DOI: 10.2147/IJN.S157426 -
Molecules (Basel, Switzerland) Mar 2013The Click-to-Chelate approach is a highly efficient strategy for the radiolabeling of molecules of medicinal interest with technetium and rhenium-tricarbonyl cores.... (Review)
Review
The Click-to-Chelate approach is a highly efficient strategy for the radiolabeling of molecules of medicinal interest with technetium and rhenium-tricarbonyl cores. Reaction of azide-functionalized molecules with alkyne prochelators by the Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC; click reaction) enables the simultaneous synthesis and conjugation of tridentate chelating systems for the stable complexation of the radiometals. In many cases, the functionalization of (bio)molecules with the ligand system and radiolabeling can be achieved by convenient one-pot procedures. Since its first report in 2006, Click-to-Chelate has been applied to the development of numerous novel radiotracers with promising potential for translation into the clinic. This review summarizes the use of the Click-to-Chelate approach in radiopharmaceutical sciences and provides a perspective for future applications.
Topics: Chelating Agents; Click Chemistry; Humans; Ligands; Radioactive Tracers; Radiopharmaceuticals; Rhenium; Staining and Labeling; Technetium
PubMed: 23481882
DOI: 10.3390/molecules18033206 -
Journal of Nuclear Medicine : Official... Mar 1992
Topics: Acupuncture Points; Attitude of Health Personnel; Cultural Characteristics; Electric Conductivity; Medicine, Ayurvedic; Medicine, East Asian Traditional; Peer Review; Technetium
PubMed: 1740712
DOI: No ID Found -
Contrast Media & Molecular Imaging 2019In the era of personalized medicine, the management of oncological patients requires a translational and multidisciplinary approach. During early phases of cancer... (Review)
Review
In the era of personalized medicine, the management of oncological patients requires a translational and multidisciplinary approach. During early phases of cancer development, biochemical alterations of cell metabolism occur much before the formation of detectable tumour masses. Current molecular imaging techniques, targeted to the study of molecular kinetics, employ molecular tracers capable of detecting cancer lesions with both high sensitivity and specificity while also providing essential information for both prognosis and therapy. On the contrary, complementary and crucial information is provided by histopathological examination and ancillary techniques such as immunohistochemistry. Thus, the successful collaboration between diagnostic imaging and anatomic pathology can represent a fundamental step in the "tortuous" but decisive path towards personalized medicine.
Topics: Humans; Molecular Imaging; Neoplasms; Precision Medicine; Prognosis; Technetium; Tomography, Emission-Computed, Single-Photon
PubMed: 31354394
DOI: 10.1155/2019/9429761 -
Molecules (Basel, Switzerland) Apr 2021The zinc dithiocarbamates functionalized with folic acid and were synthesized with a simple straightforward method, using an appropriated folic acid derivative and a...
The zinc dithiocarbamates functionalized with folic acid and were synthesized with a simple straightforward method, using an appropriated folic acid derivative and a functionalized zinc dithiocarbamate (). Zinc complexes and show very low solubilities in water, making them useful for preparing Tc-99m radiopharmaceuticals with a potentially high molar activity. Thus, the transmetallation reaction in water medium between the zinc complexes or and the cation -[Tc(HO)(CO)], in the presence of the monodentate ligand TPPTS, leads to the formation of the 2 + 1 complexes -[Tc(CO)(SS)(P)] bioconjugated to folic acid ( and ). In spite of the low solubility of and in water, the reaction yield is higher than 95%, and the excess zinc reagent is easily removed by centrifugation. The Tc-99m complexes were characterized by comparing their HPLC with those of the homologous rhenium complexes ( and ) previously synthesized and characterized by standard methods. Preliminary in vivo studies with and indicate low specific binding to folate receptors. In summary, Tc-99m folates and were prepared in high yields, using a one-pot transmetallation reaction with low soluble zinc dithiocarbamates (>1 ppm), at moderate temperature, without needing a subsequent purification step.
Topics: Folic Acid; Molecular Structure; Organic Chemicals; Rhenium; Technetium; Zinc
PubMed: 33921789
DOI: 10.3390/molecules26082373 -
European Journal of Pharmaceutical... Dec 2014Nanoscale celluloses have recently gained an increasing interest in modern medicine. In this study, we investigated the properties of plant derived nanofibrillar... (Review)
Review
Nanoscale celluloses have recently gained an increasing interest in modern medicine. In this study, we investigated the properties of plant derived nanofibrillar cellulose (NFC) as an injectable drug releasing hydrogel in vivo. We demonstrated a reliable and efficient method of technetium-99m-NFC labeling, which enables us to trace the in vivo localization of the hydrogel. The release and distribution of study compounds from the NFC hydrogel after subcutaneous injection in the pelvic region of BALB/c mice were examined with a multimodality imaging device SPECT/CT. The drug release profiles were simulated by 1-compartmental models of Phoenix® WinNonlin®. The NFC hydrogel remained intact at the injection site during the study. The study compounds are more concentrated at the injection site when administered with the NFC hydrogel compared with saline solutions. In addition, the NFC hydrogel reduced the elimination rate of a large compound, technetium-99m-labeled human serum albumin by 2 folds, but did not alter the release rate of a small compound (123)I-β-CIT (a cocaine analogue). In conclusion, the NFC hydrogels is easily prepared and readily injected, and it has potential use as a matrix for controlled release or local delivery of large compounds. The interactions between NFC and specific therapeutic compounds are possible and should be investigated further.
Topics: Animals; Cellulose; Drug Liberation; Female; Humans; Hydrogel, Polyethylene Glycol Dimethacrylate; Mice; Mice, Inbred BALB C; Nanofibers; Technetium
PubMed: 25245005
DOI: 10.1016/j.ejps.2014.09.013 -
Contrast Media & Molecular Imaging 2013Nanomedicine applications have recently gathered great attention in terms of their revolutionary properties and multivalency. Nanoparticles (NPs) have proven useful... (Review)
Review
Nanomedicine applications have recently gathered great attention in terms of their revolutionary properties and multivalency. Nanoparticles (NPs) have proven useful owing to their size, surface and kinetics advantages, as well as their ability to be functionalized with targeting, imaging and therapeutic moieties. Nuclear medicine is actively involved in nano-research innovative breakthrough efforts in multiple applications, through the radiolabeling of NP structures. There are several ways that NP-radiolabeling can be approached depending on the radionuclide that is used and the NP type. The radiolabeling of NPs with the most widely and easily available radiometal, which is (99m) Tc, is the focus of this review.
Topics: Humans; Nanomedicine; Nanoparticles; Radioisotopes; Technetium
PubMed: 23613436
DOI: 10.1002/cmmi.1530