Scandium Radioisotopes-Toward New Targets and Imaging Modalities.

The concept of theranostics uses radioisotopes of the same or chemically similar elements to label biological ligands in a way that allows the use of diagnostic and therapeutic radiation for a combined diagnosis and treatment regimen. For scandium, radioisotopes -43 and -44 can be used as diagnostic markers, while radioisotope scandium-47 can be used in the same configuration for targeted therapy. This work presents the latest achievements in the production and processing of radioisotopes and briefly characterizes solutions aimed at increasing the availability of these radioisotopes for research and clinical practice.

Increasing Reaction Rates of Water-Soluble Porphyrins for Cu Radiopharmaceutical Labeling.

Searching for new compounds and synthetic routes for medical applications is a great challenge for modern chemistry. Porphyrins, natural macrocycles able to tightly bind metal ions, can serve as complexing and delivering agents in nuclear medicine diagnostic imaging utilizing radioactive nuclides of copper with particular emphasis on Cu. This nuclide can, due to multiple decay modes, serve also as a therapeutic agent.

Porphyrins as Chelating Agents for Molecular Imaging in Nuclear Medicine.

Porphyrin ligands, showing a significant affinity for cancer cells, also have the ability to chelate metallic radioisotopes to form potential diagnostic radiopharmaceuticals. They can be applied in single-photon emission computed tomography (SPECT) and positron emission tomography (PET) to evaluate metabolic changes in the human body for tumor diagnostics. The aim of this paper is to present a short overview of the main metallic radionuclides complexed by porphyrin ligands and used in these techniques.

Molecular imaging of myogenic stem/progenitor cells with [F]-FHBG PET/CT system in SCID mice model of post-infarction heart.

Preclinical and clinical studies have shown that stem cells can promote the regeneration of damaged tissues, but therapeutic protocols need better quality control to confirm the location and number of transplanted cells. This study describes in vivo imaging while assessing reporter gene expression by its binding to a radiolabelled molecule to the respective receptor expressed in target cells. Five mice underwent human skeletal muscle-derived stem/progenitor cell (huSkMDS/PC EF1-HSV-TK) intracardial transplantation after induction of myocardial infarction (MI).

Does the Caesarean Section Impact on 11β HSD2 and Fetal Cortisol?

Purpose: Comparison of the activity of 11beta-hydroxysteroid dehydrogenase type 2 in the placenta and the umbilical cord blood cortisol level between caesarean sections with or without uterine contraction and vaginal delivery groups. Cortisol is the main stress hormone responsible for the normal adaptation of the neonate to extrauterine life. The disorders resulting from a dysfunction of the 11β-HSD 2-cortisol system can explain the higher risk of developing diseases in children born by caesarean section.

Synthesis, physicochemical and biological evaluation of tacrine derivative labeled with technetium-99m and gallium-68 as a prospective diagnostic tool for early diagnosis of Alzheimer's disease.

Design, physicochemical and biological studies of novel radioconjugates for the early diagnosis of Alzheimer's disease, based on the newly synthesized tacrine derivatives were performed. Novel tacrine analogues were labeled with technetium-99m and gallium-68. For all obtained radioconjugates ([Tc]Tc-Hynic-(tricine)NH(CH)tacrine and [Ga]Ga-DOTA-NH(CH)tacrine, where n = 2-9 denotes the number of methylene groups CH) the studies of physicochemical properties (lipophilicity, stability in the presence of an excess of standard amino acids cysteine or histidine, human serum and in cerebrospinal fluid) were performed.

Changes in hypoxia level of CT26 tumors during various stages of development and comparing different methods of hypoxia determination.

The aim of this study was to evaluate hypoxia level at various tumor developmental stages and to compare various methods of hypoxia evaluation in pre-clinical CT26 tumor model. Using three methods of hypoxia determination, we evaluated hypoxia levels during CT26 tumor development in BALB/c mice from day 4 till day 19, in 2-3 days intervals. Molecular method was based on the analysis of selected genes expression related to hypoxia (HIF1A, ANGPTL4, TGFB1, VEGFA, ERBB3, CA9) or specific for inflammation in hypoxic sites (CCL2, CCL5) at various time points after CT26 cancer cells inoculation.

Alpha-Tocopherol Serum Levels Are Increased in Caucasian Women with Uterine Fibroids: A Pilot Study.

Uterine fibroids (UFs) are benign tumors of the reproductive tract, arising from smooth muscle cells of the uterus. Steroid hormones, estrogen, and progesterone are considered to be the most important links in the pathophysiology of UFs. Alpha-tocopherol (AT) is the most active form of vitamin E.

Separation of Sc from Natural Calcium Carbonate Targets for Synthesis of Sc-DOTATATE.

The rapid increase in applications of scandium isotopes in nuclear medicine requires new efficient production routes for these radioisotopes. Recently, irradiations of calcium in cyclotrons by α, deuteron, and proton beams have been used. Therefore, effective post-irradiation separation and preconcentration of the radioactive scandium from the calcium matrix are important to obtain the pure final product in a relatively small volume.

The fast method of Cu-porphyrin complex synthesis for potential use in positron emission tomography imaging.

Porphyrin based photosensitizers are useful agents for photodynamic therapy and fluorescence imaging of cancer. Additionally, porphyrins are excellent metal chelators, forming stable metalo-complexes and (64)Cu isotope can serve as a positron emitter (t1/2=12.7h).

Ga-DOTA and analogs: Current status and future perspectives.

The construction of the Ge/Ga generator has increased application of radiopharmaceuticals labeled with this isotope in medicine. Ga-PET is widely employed in the management of neuroendocrine tumors but favorable chemistry with tri- and tetraaza-ring molecules has opened wide range of Ga application in other fields of PET imaging. This review covers the radiopharmaceuticals labeled with gallium in molecular imaging and shows perspectives on the use of gallium-68 as a substitute for technetium-99, fluorine-18 and carbon-11 in some applications.

Synthesis, quality control and determination of metallic impurities in F-fludeoxyglucose production process.

Aim: The aim of this study was to synthesize FDG in some consecutive runs and check the quality of manufactured radiopharmaceuticals and to determine the distribution of metallic impurities in the synthesis process.

Background: For radiopharmaceuticals the general requirements are listed in European Pharmacopeia and these parameters have to be checked before application for human use.

Materials And Methods: Standard methods for the determination of basic characteristics of radiopharmaceuticals were used.

Spectrophotometric study of Cd(II), Pb(II), Hg(II) and Zn(II) complexes with 5,10,15,20-tetrakis(4-carboxylphenyl)porphyrin.

The reaction of 5,10,15,20-tetrakis(4-carboxylphenyl)porphyrin (TCPP) with Cd(II), Pb(II), Hg(II) and Zn(II) was studied spectrophotometrically and kinetics, equilibrium constants as well as photodecomposition of complexes were determined. It was verified that these metal ions with large radius accelerate the incorporation reaction of zinc into TCPP. On the basis of the mechanism and kinetics of this reaction, a sensitive method for the spectrophotometric determination of trace amounts of Zn(II) has been developed.

On-line sorption-based systems for determination of cadmium with atomic spectrometry detectors.

Determination of cadmium is often required in various environmental, biological and food samples as it is recognized worldwide as a toxic metal. However, these analysis with atomic spectrometry detectors are often difficult due to relatively low content of cadmium and complex matrices. Several preconcentration/separation procedures to determine cadmium have been devised, among them the methods based on sorbent extraction are the most popular.

On-line enrichment system for manganese determination in water samples using FAAS.

An on-line preconcentration procedure for the determination of manganese using flow-injection approach with flame atomic absorption spectrometry as a detection method is described. The proposed method is based on the complexation between Mn(II) and 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (TCPP). Two approaches were investigated for enrichment of manganese; the formation of Mn-TCPP complex in a solution followed by its retention on a sorbent and the sorption of manganese ions onto the TCPP-modified resin.

Original paper application of cyclodextrins as modifiers in electrophoretic separation of metalloporphyrins.

Several metallocomplexes of tetrakis-carboxyphenylporphyrin (TCPP) were separated on fused-silica capillary using CZE with UV-VIS detection. Metalloporphyrins of Co(II), Cu(II), Mn(II), Ni(II), and Zn(II) were formed directly in TCPP solution with addition of Cd(II) to increase the formation reaction rate. The composition of BGE, its concentration, and pH were optimized to ensure the stability of complexes and proper resolution.

Capillary electrophoresis speciation of chromium in leather tanning liquor.

We present a method for the speciation of chromium by capillary electrophoresis. Cr(III) was complexed with diethylenetriaminepentaacetic acid (DTPA) to form a negatively charged complex. Using 20 mM phosphate buffer of pH 8 containing 0.

Application of 5,10,15,20-tetrakis(4-carboxyphenyl)porphine for cadmium preconcentration in flow-injection system.

The suitability of 5,10,15,20-tetrakis(4-carboxyphenyl)porphine as a complexing agent for the on-line preconcentration of cadmium using an anion exchanger (Amberlite IRA-904) in a microcolumn has been tested. Various parameters which affect complex formation and its sorption, as well as elution into the nebulizer of flame atomic absorption spectrometry (FAAS), were optimized. A 5 x 10(-4) mol 1(-1) reagent was on-line mixed with an aqueous sample solution and flowed through the microcolumn for 2 min.