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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 -
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 -
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 -
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 -
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 -
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 -
The Tohoku Journal of Experimental... Apr 2009Radiopharmaceuticals are used in nuclear medicine for diagnostic and therapeutic purposes. Many adverse reactions and false positive reactions related to... (Review)
Review
Radiopharmaceuticals are used in nuclear medicine for diagnostic and therapeutic purposes. Many adverse reactions and false positive reactions related to radiopharmaceuticals take place every day in hospitals, but most of them are not reported. It is therefore important to understand the definition of each undesirable reaction. Adverse reactions are defined as any noxious or unintended reactions to a drug, which is administered in standard doses through the proper route for the purpose of prophylaxis, diagnosis, or treatment. False positive reactions can be defined as any imaging appearance caused by undue physiological or pathological accumulation of radiopharmaceuticals. Information concerning these undesirable reactions is limited for radiopharmaceuticals. The present study intends to be a source of information that could be accessed by all nuclear medicine staff. A review of the literature from 1957 to January 2009 was carried out using the criteria of a systematic review, established by the Cochrane Collaboration, an international non-profit organization, that provides up-to-date information about the health care. The present study has revealed that radiopharmaceuticals cause adverse reactions. Six cases of adverse reactions with radiopharmaceuticals were found: 2 cases with (18)F-fluorodeoxyglucose (FDG) and 4 cases with technetium 99m ((99m)Tc). Among the 4 cases of adverse reactions with (99m)Tc, one subject who received (99m)Tc-labeled sestamibi developed anaphylactic reactions. Moreover, a total of 8 cases with false positive reactions were found with FDG. In conclusion, a worldwide effort should be made to report as many cases as possible of adverse events and false positive reactions with radiopharmaceuticals.
Topics: False Positive Reactions; Fluorodeoxyglucose F18; Humans; Nuclear Medicine; Radiopharmaceuticals; Technetium
PubMed: 19346729
DOI: 10.1620/tjem.217.251 -
Journal of Medicinal Chemistry Apr 2023Technetium-99m is the workhorse of diagnostic nuclear medicine. The aim of the work is to analyze the technetium-99m patents since 2000 to photograph its innovation.... (Review)
Review
Technetium-99m is the workhorse of diagnostic nuclear medicine. The aim of the work is to analyze the technetium-99m patents since 2000 to photograph its innovation. QUESTEL's ORBIT Intelligence system was used for the collection of technetium inventions disclosed in patents and patent applications in more than 96 countries in the period 2000-2022; 2768 patent documents were analyzed. Patent counting and analysis have shown that SPECT imaging using technetium-99m radiopharmaceuticals is still robust. The introduction of new technetium-99m radiopharmaceuticals into clinical routine goes beyond successful trials. In eastern economies, such as China and other emerging markets, patent applications are on the rise, while those in developed western countries are stagnating, with some exceptions for the United States. But despite the difficulties, academic and industrial research on these tracers remains essential for the development of nuclear medicine.
Topics: United States; Technetium; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon; China
PubMed: 37010457
DOI: 10.1021/acs.jmedchem.3c00148 -
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