Preparation, molecular modeling and biodistribution of 99mTc-phytochlorin complex

Multi-functionalization of reduced graphene oxide nanosheets for tumor theragnosis: Synthesis, characterization, enzyme assay, in-silico study, radiolabeling and in vivo targeting evaluation

BACKGROUND

In this study, a combination of nanotechnology, organic synthesis and radiochemistry were utilized in order to design an efficient nano-system conjugated with a suitable radionuclide and an antitumor agent for possible application as tumor theragnostic agent.

METHOD

Four novel compounds (3 and 4a-c) bearing tetrahydroquinazoline-7-sulfonohydrazide or 1,2,3,4-tetrahydroquinazoline-7-sulfonamide scaffold were designed. Then, docking study predicted that the compounds can be considered as potential inhibitors for PARP-1. Following that; the four compounds were synthesized and properly characterized using 1HNMR, 13CNMR, IR and Mass spectroscopy. The cytotoxic effect of the four compounds was evaluated against breast cancer cell line (MDA-MB-436), where compound 3 showed the most promising cytotoxic effect. The inhibitory effect of the four compounds was evaluated in vitro against PARP-1.

RESULT

Carboxylated graphene oxide nanosheets (NGO-COOH) were synthesized by a modified Hummer's method and has size of range 40 nm. The NGO-COOH nanosheets were proven to be safe and biocompatible when tested in vitro against normal human lung fibroblast cells (MRC-5). The prepared NGO-COOH nanosheets were conjugated with compound 3 then radiolabeled with 99mTc to yield 99mTc-NGO-COOH-3 with a radiochemical yield of 98.5.0 ± 0.5%. 99mTc-NGO-COOH-3 was injected intravenously in solid tumor bearing mice to study the degree of localization of the nano-system at tumor tissue. The results of the study revealed, excellent localization and retention of the designed nano-system at tumor tissues with targeting ratio of 9.0.

CONCLUSION

Stirred a new candidate tumor theragnostic agent that is safe, selective and stable.

Furosemide drug as a corrosion inhibitor for carbon steel in 1.0 M hydrochloric acid

Furosemide (4-chloro-2-furan-2-ylmethylamino-5-sulfamoylbenzoic acid) was examined as an inhibitor for the corrosion of carbon steel (CS) in 1.0 M HCl. The investigation included mass loss (ML) and electrochemical techniques: potentiodynamic polarization (PP), electrochemical impedance spectroscopy (EIS), and electrochemical frequency modulation (EFM). The efficiency of inhibition rises with increasing Furosemide concentration and temperature. This compound follows the Temkin isotherm with good fit. The presence of varying quantities influences both anodic metal dissolution and cathodic hydrogen evolution. Scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FT-IR) were used to detect the effect of the compound on the CS surface. The molecular inhibitory effect of Furosemide was demonstrated using quantum chemical calculations, and the molecular simulation results demonstrated the adsorption on the carbon steel surface.

A review of recent advancements in Actinium-225 labeled compounds and biomolecules for therapeutic purposes

In nuclear medicine, cancers that cannot be cured or can only be treated partially by traditional techniques like surgery or chemotherapy are killed by ionizing radiation as a form of therapeutic treatment. Actinium-225 is an alpha-emitting radionuclide that is highly encouraging as a therapeutic approach and more promising for targeted alpha therapy (TAT). Actinium-225 is the best candidate for tumor cells treatment and has physical characteristics such as high (LET) linear energy transfer (150 keV per μm), half-life (t1/2  = 9.92d), and short ranges (400-100 μm) which prevent the damage of normal healthy tissues. The introduction of various new radiopharmaceuticals and radioisotopes has significantly assisted the advancement of nuclear medicine. Ac-225 radiopharmaceuticals continuously demonstrate their potential as targeted alpha therapeutics. 225 Ac-labeled radiopharmaceuticals have confirmed their importance in medical and clinical areas by introducing [225 Ac]Ac-PSMA-617, [225 Ac]Ac-DOTATOC, [225 Ac]Ac-DOTA-substance-P, reported significantly improved response in patients with prostate cancer, neuroendocrine, and glioma, respectively. The development of these radiopharmaceuticals required a suitable buffer, incubation time, optimal pH, and reaction temperature. There is a growing need to standardize quality control (QC) testing techniques such as radiochemical purity (RCP). This review aims to summarize the development of the Ac-225 labeled compounds and biomolecules. The current state of their reported resulting clinical applications is also summarized as well.

Enhancing the inhibition and adsorption performance of SABIC iron corrosion in sulfuric acid by expired vitamins. Experimental and computational approach

The inhibition potency of expired thiamine or vitamin B1 (VB1) and riboflavin or vitamin B2 (VB2) against SABIC iron corrosion in 0.5 M H₂SO₄ solutions was investigated using chemical and electrochemical techniques. Theoretical studies such as DFT and MC simulations were performed on both VB1 and VB2 inhibitors to obtain information related to the experimental results. It has been found that the inhibition efficacy assigned from all measurements used increases with increasing concentration of the two expired vitamins and reduces at elevated temperatures. It reached 91.14% and 92.40% at 250 ppm of VB1 and VB2, respectively. The inhibition was explicated by the adsorption of the complex formed between expired vitamins and ferrous ions on the SABIC iron surface. The adsorption was found to obey the Langmuir isotherm model. Galvanostatic polarization demonstrated that the two expired vitamins act as an inhibitor of the mixed type. These expired vitamins have proven effective in inhibiting the pitting corrosion induced by the presence of Cl^- ions. The pitting potential is transferred to the positive values showing resistance to pitting damage. The theoretical parameter values are consistent with experimental results.

Radiosynthesis, molecular modeling and biodistribution of 99mTc-Protoporphyrin as a preclinical model for tumor diagnosis

Porphyrins are among the most important and widely used compounds involved in a variety of chemical and biochemical applications. These molecules exhibit very special properties that encourage researchers to label many derivatives with diagnostic or therapeutic radionuclides for medical applications. This study reports the radiolabeling and biodistribution of [Formula: see text]Tc-protoporphyrin IX ([Formula: see text]Tc-PPIX) as a novel potential solid-tumor imaging agent. The factors affecting the radiolabeling process were varied to achieve maximum radiochemical yield. [Formula: see text]Tc-PPIX was obtained in high yield of 97.34 ± 0.21% and high stability in serum up to 24 h. The radiochemical yield of [Formula: see text]Tc-PPIX was assessed by a combination of a paper chromatographic technique and HPLC. A computational analysis for all the potential structures that may be formed due to the interaction between protoporphyrin IX and technetium was performed via the DFT method of calculations in gas phase to predict the most likely structure. Molecular docking was further employed to shed light on the nature of the interaction between the most stable complexes with the target protein. Finally, the in-vivo biodistribution of [Formula: see text]Tc-PPIX complex was evaluated in solid-tumor-bearing mice and high tumor/tissue ratio of 5.17 ± 0.34 at 60 min post injection was obtained. Our finding clearly suggests [Formula: see text]Tc-PPIX as a potential SPECT agent for tumor imaging.

A novel 99m Tc-diester complex as tumor targeting agent: Synthesis, radiolabeling, and biological distribution study

The target of this study is the synthesis of a new diester derivative and radiolabeling with one of the most effective diagnostic radioisotopes to be investigated as a novel targeting radiotracer for tumor imaging. 10-[2-(9-Carboxynonanoyloxy)propoxy]-10-oxodecanoic acid was synthesized in excellent yield and characterized by Fourier-transform infrared spectroscopy, mass, 1 H-NMR, and 13 C-NMR spectra. The diester was technetium-99m (99m Tc) radiolabeled by direct technique using sodium dithionite as a reducing agent. The labeling parameters such as diester amount, reducing agent amount, pH of the medium, and reaction time were optimized. High radiochemical yield of 95.10 ± 0.41% and in vitro stability in serum up to 12 h have been obtained on complexation of the synthesized diester with Tc-99m. Evaluation of the diester anticancer activity against breast cancer cell line (MCF-7) showed high percent of inhibition about 61.5% at 100 μg/ml. The rhenium complex of the diester was synthesized and characterized by liquid chromatography-mass spectrometry (ESI) and elemental analysis depending on the strong chemical resemblance between Tc and Re. Biodistribution studies of 99m Tc-diester complex showed high target to nontarget ratio (T/NT) equals 6.24 ± 0.09 in tumor-bearing mice at 30-min postinjection, suggesting this complex could be used as hopeful solid tumor-imaging agent.