Radioiodination and bioevaluation of rolipram as a tracer for brain imaging: In silico study, molecular modeling and gamma scintigraphy

Unlocking the potential: phenylboronic acid as a nuclear-targeting boron agent for neutron capture therapy

It has been proposed that boron neutron capture therapy (BNCT) holds promise as a treatment modality for melanoma. However, the effectiveness of boron agents in delivery remains a critical issue to be addressed for BNCT. To this end, phenylboronic acid, which exhibits good water solubility and low cytotoxicity similar to BPA, has been investigated as a potential nuclear-targeting boron agent. The boron concentration of phenylboronic acid was found to be 74.47 ± 12.17 ng/106 B16F10 cells and 45.77 ± 5.64 ng/106 cells in the nuclei. Molecular docking experiments were conducted to investigate the binding of phenylboronic acid to importin proteins involved in nuclear transport. The potential of phenylboronic acid to serve as a desirable nucleus-delivery boron agent for neutron capture therapy in melanoma warrants further exploration.

Preparation, biological evaluation and radiolabeling of [99mTc]-technetium tricarbonyl procainamide as a tracer for heart imaging in mice

This study focuses on the synthesis and preliminary bio-evaluation of [99mTc]-technetium tricarbonyl procainamide ([99mTc]-technetium tricarbony PA) as a viable cardiac imaging agent. The compound, [99mTc]-technetium tricarbony PA, was synthesized by labelling procainamide with a [99mTc]-technetium tricarbonyl core, yielding a high radiochemical yield and radiochemical purity of 98%. Under optimal circumstances, high radiochemical yield and purity were obtained utilizing [99mTc]-technetium tricarbonyl core within 30 min of incubation at pH 9, 200 µg substrate concentration, and 100 °C reaction temperature. The heart showed a high absorption of 32.39 ± 0.88% of the injected dose/g organ (ID/g), confirming the suitability of [99mTc]-technetium tricarbonyl PA as a viable complex for heart imaging.

Enhancement of the thermal and physicochemical properties of styrene butadiene rubber composite foam using nanoparticle fillers and electron beam radiation

This study investigates the physicochemical and thermal properties of styrene–butadiene rubber (SBR) nanocomposite foam. Nano-calcium carbonate (CaCO3) was prepared from eggshells (ESs) waste. Sponge rubber nanocomposites were prepared and were irradiated by electron beam (EB) radiation at 25, 75, and 150 kGy. Their physicochemical properties, including foam density, compression set (CS), hardness, abrasion loss, and expansion ratio, and their thermal stability were investigated. The physicochemical properties were enhanced by adding 2.5 phr of a foaming agent. Among the composites examined, the foam composites containing nano-CaCO3 had the lowest CS, abrasion loss, and expansion ratio and the highest hardness and foam density. The results confirmed that the thermal stability was improved by incorporating nano-CaCO3 into the SBR foam and as the radiation dose increased. The sponge containing nanoclay demonstrated an intermediate behavior, whereas that with CaCO3 nanoparticles showed low average cell diameter and size and high cell wall thickness. The radiation process enhanced the foam density, CS, abrasion loss, hardness, and thermal property of the developed nanocomposites by inducing the formation of intermolecular crosslinks within the composite matrix. The results showed that physicochemical properties improved by increasing the radiation dose at 25 kGy.

Radioiodination of balsalazide, bioevaluation, and characterization as a highly selective radiotracer for imaging of ulcerative colitis in mice

This work focuses on tracking ulcerative colitis in mice. High labeling yield and radiochemical purity were achieved for the formation of a [^125/131 I]balsalazide radiotracer at optimum conditions of oxidizing agent content (chloramines-T [Ch-T], 75 μg), substrate amount (100 μg), pH of reaction mixture (6), reaction time (30 min), and temperature (37°C), using radioactive iodine-125 (200-450 MBq). The radiolabeled compound, [^125/131 I]balsalazide, was stable in serum and saline solution during 24 h. Balsalazide is acting as a peroxisome proliferator-activated receptor (PPARγ). Biodistribution studies were carried in normal and ulcerated colon mice. High uptake of 75 ± 1.90% injected dose/g organ (ID/g) observed in ulcerated mice confirmed the suitability of [¹³¹ I]balsalazide as a novel radiotracer for ulcerative colitis imaging in mice.

Preparation, characterization, and bioevaluation of 99mTc-famotidine as a selective radiotracer for peptic ulcer disorder detection in mice

This work focuses on tracking peptic ulcer localized in mice. The formation of a [99mTc]dithiocarbamate of famotidine complex at optimum conditions of reaction temperature (37 °C), reaction time (30 min), pH of the reaction mixture (5), amount of substrate (100 µg), amount of reducing agent (tin (II) content, 50 µg), was achieved using radioactive Tc-99m (250–400 MBq), with labelling yield of 98% and high radiochemical purity. The in-vitro stability of [99mTc]dithiocarbamate of famotidine complex was shown to be high in rat serum for up to 8 h. Normal and ulcerated mice were used in biodistribution studies. Famotidine works by blocking histamine-2-receptor antagonists (H2RAs). The high absorption of [99mTc]dithiocarbamate of famotidine complex in stomach in amount of 27.15% injected dose/g organ (ID/g) observed in ulcerated mice for up to 24 h demonstrated its usefulness as a novel radiotracer for stomach imaging.

Radiosynthesis and in silico bioevaluation of 131 I-Sulfasalazine as a highly selective radiotracer for imaging of ulcerative colitis

This study demonstrated the tracking of ulcerative colitis, which is considered a stressful immune disease. Although there are many ways to test for this disease including dependence on gases, dyes, and painful anal endoscopy, these treatment modalities have many disadvantages. Hence, it is the utmost need of time to discover new methods to detect this chronic immune disease and to avoid the defects of traditional methodologies. Sulfasalazine (SSD) was labeled with iodine-131 (half-life: 8 days, Energy: 971 keV) under optimum reaction conditions including the amount of reducing agent, pH factor, chloramine-T (Ch-T) amount, and incubation period. Characterization was performed using ¹ H/ ¹³ C-NMR, ESI-MS, and HPLC (UV/ Radio) techniques. The biodistribution study was performed in normal and ulcerative mice models, and in silico molecular docking study was performed to evaluate the possible mechanism of action to target peroxisome proliferator-activated receptor gamma (PPARγ). The high radiolabeling yield of [¹³¹ I]-sulfasalazine ([¹³¹ I]-SSD) was achieved ≥90% through the direct labeling method with radioactive iodine-131 in the presence of chloramine-T (100 μg). The radiotracer [¹³¹ I]-SSD was observed to be stable in normal saline and freshly eluted serum up to 12 hr at ambient temperature (37℃ ± 2℃). The radiotracer [¹³¹ I]-SSD showed the highest uptake in the targeted organ (i.e., ulcerative colon) which was observed to be ≥75% injected dose per gram (% ID/g) organ for 24 hr postinjection (p.i). Furthermore, in silico data collected from molecular modeling analysis of SSD and [¹³¹ I]-SSD with antimicrobial protein (PDB code: 3KEG) and peroxisome proliferator-activated receptor gamma (PPARγ) (PDB code: 4XTA) showed azoreductase activity and high binding potential for PPAR-γ site, respectively. The results of biological studies obtained in this study enlighten the usefulness of radiotracer [¹³¹ I]-SSD as a potential imaging agent for ulcerative colitis.

Radioiodinated esomeprazole as a model for peptic ulcer localization

This work focuses on tracking stomach ulcer localized in mice. High labeling yield and radiochemical purity were achieved for the formation of a [125I]esomeprazole radiotracer at optimum conditions of oxidizing agent content (chloramines-T (Ch-T), 100 μg), substrate amount (Esom, 100 μg), pH of reaction mixture (6), reaction time (30 min) and temperature (37 °C), using radioactive iodine-125 (200–450 MBq). The radiolabeled compound, [125I]esom, was stable in serum and saline solution during 24 h. Esom is acting as a histamine-2-receptor antagonist (H2RA). Biodistribution studies were carried in normal and ulcerated mice. High uptake of 78.12 ± 0.80% injected dose/g organ (ID/g) observed in ulcerated mice confirmed the suitability of [125I]esomeprazole as a novel radiotracer for stomach imaging.

In silico and in vivo study of radio-iodinated nefiracetam as a radiotracer for brain imaging in mice

This study presents development and characterization of a radiotracer, [125I]iodonefiracetam ([125I]iodoNEF). Labeling with high yield and radiochemical purity was achieved through the formation of a [125I]iodoNEF radiotracer after investigating many factors like oxidizing agent content (chloramines-T (Ch-T)), substrate amount (Nefiracetam (NEF)), pH of reaction mixture, reaction time and temperature. Nefiracetam (NEF) is known as nootropic agent, acting as N-methyl-d-aspartic acid receptor ligand (NMDA). The radiolabeled compound was stable, and exhibited the logarithm of the partition coefficient (log p) value of [125I]iodonefiracetam as 1.85 (lipophilic). Biodistribution studies in normal mice confirmed the suitability of the [125I]iodoNEF radiotracer as a novel tracer for brain imaging. High uptake of 8.61 ± 0.14 percent injected dose/g organ was observed in mice

Synthesis, characterization, and bioevaluation of 99mTc nitrido-oxiracetam as a brain imaging model

In this work, the radiotracer [99mTc]nitrido-oxiracetam complex was labeled in the presence of 99mTc-nitrido as a core. In order to get the highest radiochemical purity, many effective factors have been studied such as temperature of the reaction, time of the reaction, the pH of the reaction mixture, substrate amount, and stability to give high percent more than 99%. Finally, biodistribution studies have been indicated the convenience of [99mTc]nitrido-oxiracetam as a new radiotracer that could be used in brain imaging. Giving a maximum uptake of 10.6% at 30 min post injection.

Radioiodination and biological evaluation of irbesartan as a tracer for cardiac imaging

Irbesartan was labeled using 125I or 131I with N-bromosuccinimide (NBS) as an oxidizing agent. A lot of operators such as, quantity of substrate, the quantity of oxidizing agent, reaction temperature, reaction time, and pH of reaction medium were studied to optimize high radiochemical yield of [125I]IodoIrbesartan ([125I]Irb.). The preclinical evaluation of IodoIrbesartan in experimental mice indicated high accumulation in target organ of heart with a high heart/blood ratio of 12.85 at 30 min post-injection. This study indicates the suitability of [125I]IodoIrbesartan ([125I]Irb.) for cardiac imaging.

Radioiodination and biological evaluation of landiolol as a tracer for myocardial perfusion imaging: preclinical evaluation and diagnostic nuclear imaging

The present work has assessed the ability and competency of radioiodinated landiolol that is considered a potential cardio selective imaging agent. Landiolol was radiosynthesized with [131I] using chloramine-T (Ch-T) as an oxidizing agent. To give high radiochemical yield of the [131I]landiolol reaching values of 98% with high stability up to 48 h. The labeled compound was separated and purified using thin layer chromatography (TLC), paper electrophoresis and high performance liquid chromatography (HPLC). Biodistribution studies indicated that [131I]landiolol gave high heart uptake ratio of [45.0±0.19% ID/g at 2 min post injection (p.i.)]. Therefore, [131I]landiolol could be considered as a novel tracer to image heart with high heart/blood ratio within 60 min.

Radioiodination, diagnostic nuclear imaging and bioevaluation of olmesartan as a tracer for cardiac imaging

The present work has been oriented to prepare radioiodinated olmesartan for a potential cardiac imaging. Olmesartan has been labeled using 125I or 131I with N-bromosuccinimide (NBS) as an oxidizing agent. Many factors like amount of N-bromosuccinimide, amount of substrate, pH, reaction temperature and reaction time, have been systematically studied to optimize high yield of [125I]iodoolmesartan. The biological distribution indicates the suitability of [125I]iodoolmesartan as a novel tracer to image heart.