Compartmental modeling and simplified quantification of [¹¹C]sertraline distribution in human brain.

Sertraline hydrochloride (Zoloft®, Pfizer) is an antidepressant drug of the selective serotonin reuptake inhibitor (SSRI). The aims of this study were evaluating its in vivo distribution and kinetic models in human brain. Also, this study was to determine optimal scan duration of dynamic positron emission tomography (PET) for accurate [¹¹C]sertraline kinetic parameters and the feasibility of semi-quantitative approach for assessing distribution volume ratio (DVR).

Hypoxia imaging agents labeled with positron emitters.

Imaging hypoxia using positron emission tomography (PET) is of great importance for therapy of cancer. [(18)F]Fluoromisonidazole (FMISO) was the first PET agent for hypoxia imaging, and various radiolabeled nitroimidazole derivatives such as [(18)F]fluoroerythronitroimidazole (FETNIM), [(18)F]1-α-D: -(2-deoxy-2-fluoroarabinofuranosyl)-2-nitroimidazole (FAZA), [(18)F]2-(2-nitro-1H-imidazol-1-yl)-N-(2,2,3,3,3-pentafluoropropyl) acetamide (EF-5), and [(18)F]fluoroetanidazole (FETA) have been developed successively. To overcome the high cost of cyclotron installation, (68)Ga-labeled nitroimidazole derivatives also have been developed.

Development of a bifunctional chelating agent containing isothiocyanate residue for one step F-18 labeling of peptides and application for RGD labeling.

We report herein a novel isothiocyanate active ligand for fluorine-18 labeling prepared by four step synthesis. It can be conjugated to a target molecule containing an amino functional group under weak basic conditions by way of thiourea bond formation. We explored the application of synthesized ligand by conjugating to well known α(v)β(3) integrin targeting peptide, c(RGDyK).

Nanoparticles modified by encapsulation of ligands with a long alkyl chain to affect multispecific and multimodal imaging.

Unlabelled: The attachment of specific ligands to the surfaces of nanoparticles is important for medical and biologic imaging. However, covalent modification of nanoparticles has inherent problems in reproducibility because of many factors such as temperature, pH, concentration, and reaction time. Thus, we developed a method for modifying nanoparticles by encapsulation with specific ligand-conjugated amphiphiles.

Syntheses of 2-nitroimidazole derivatives conjugated with 1,4,7-triazacyclononane-N,N'-diacetic acid labeled with F-18 using an aluminum complex method for hypoxia imaging.

Hypoxia imaging is important for diagnosis of ischemic diseases, and thus various (18)F-labeled radiopharmaceuticals have been developed. However, (18)F-labeling requires multistep procedures including azeotropic distillation, which is complicated and difficult to automate. Recently, (18)F-labeling method using Al-F complex in aqueous solution was devised that offered a straightforward (18)F-labeling procedure.

Stable aluminium fluoride chelates with triazacyclononane derivatives proved by X-ray crystallography and 18F-labeling study.

A single crystal structure of an aluminium-fluoride complex of a model compound (NODA-benzyl) was studied to understand the co-ordination chemistry. Series of ligands with an extra carboxylic acid linker for biomolecule conjugation were studied for improved (18)F-labeling applications.

Synthesis of 68Ga-labeled DOTA-nitroimidazole derivatives and their feasibilities as hypoxia imaging PET tracers.

The imaging of hypoxia is important for therapeutic decision making in various diseases. (68)Ga is an important radionuclide for positron emission tomography (PET), and its usage is increasing, due to the development of the (68)Ge/(68)Ga-generator. In the present study, the authors synthesized two nitroimidazole derivatives by conjugating nitroimidazole and 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) via an amide bond (4) and a thiourea bond (5).

Synthesis and characterization of nitroimidazole derivatives for 68Ga-labeling and testing in tumor xenografted mice.

Radiolabeled nitroimidazole (NI) derivatives have been used for imaging hypoxic tissues. We synthesized NI derivatives conjugated with bifunctional chelating agents such as 1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA) and isothiocyanatobenzyl-NOTA (SCN-NOTA) via ethyleneamine bridge by formation of amide and thiourea bond, respectively. We proved that amide oxygen of Ga-NOTA-NI contributes to the formation of metal complex by X-ray crystallography.