Search results for "dota"

Synthesis and study of new fluorescent probes for optical imaging, Cherenkov imaging and multimodal imaging

2015

The goal of this work was to prepare and study new fluorescent probes, which could give rise to novel optical or Cherenkov imaging agents. The first section of this work describes the synthesis of fluorescent subphthalocyanines and phthalocyanines probes, which possess relevant chemicals groups suitable for optical imaging applications. The optical and physico-chemical properties of the new probes were carefully examined to ensure they comply with the specification of the fluorophores for the desired application. The second part focused on the subsequent development of a few selected probes into real imaging agents. The biovectorisation of subphtalocyanines was achieved upon conjugation of …

Harnessing medically relevant metals onto water-soluble subphthalocyanines: towards bimodal imaging and theranostics

2014

International audience; Subphthalocyanine (SubPc), a putative fluorophore for optical imaging (OI), was conjugated to chelating ligands (DOTA, DTPA) affording water-soluble conjugates complexed with (non-radioactive) metals relevant to the following medical imaging techniques/therapies: MRI (Gd), PET (Cu, Ga), SPECT (In, Ga, Lu), RIT (Cu, Lu, Y), and NCT (Gd). Magneto-optical properties of ditopic gadolinium species (and optical properties of other metal containing species) were examined (brightness (ε × Φ F) and relaxivity R 1) and fluorescence confocal/biphoton microscopy studies were conducted. † Electronic supplementary information (ESI) available: Experimental characterization, NMR and…

The Use of the Macrocyclic Chelator DOTA in Radiochemical Separations

2019

Zvaigžņotā Debess: 2006, Pavasaris

2006

Latvijas Zinātnes padome, Latvijas Universitāte

DOTAGA-anhydride: a valuable building block for the preparation of DOTA-like chelating agents.

2012

International audience; A DOTA derivative that contains an anhydride group was readily synthesized by reacting DOTAGA with acetic anhydride and its reactivity was investigated. Opening the anhydride with propylamine led to the selective formation of one of two possible regioisomers. The structure of the obtained isomer was unambiguously determined by 1D and 2D NMR experiments, including COSY, HMBC, and NOESY techniques. This bifunctional chelating agent offers a convenient and attractive approach for labeling biomolecules and, more generally, for the synthesis of a large range of DOTA derivatives. The scope of the reaction was extended to prepare DOTA-like compounds that contained various f…

Scandium(III) complexes of monophosphorus acid DOTA analogues: a thermodynamic and radiolabelling study with 44 Sc from cyclotron and from a 44 Ti/ 4…

2015

International audience; The complexation ability of DOTA analogs bearing one methylenephosphonic (DO3AP) or methylene-phosphinic (DO3AP PrA and DO3AP ABn) acid pendant arm toward scandium was evaluated. Stability constants of their scandium(III) complexes were determined by potentiometry combined with 45 Sc NMR spectroscopy. The stability constants of the monophosphinate analogues are somewhat lower than that of the Sc–DOTA complex. The phosphorus acid moiety interacts with trivalent scandium even in very acidic solutions forming out-of-cage complexes; the strong affinity of the phosphonate group to Sc(III) precludes stability constant determination of the Sc–DO3AP complex. These results we…

44Sc-DOTA-BN[2-14]NH2 in comparison to 68Ga-DOTA-BN[2-14]NH2 in pre-clinical investigation. Is 44Sc a potential radionuclide for PET?

2011

In the present study we demonstrate the in vitro and in vivo comparison of the (44)Sc and (68)Ga labeled DOTA-BN[2-14]NH(2). (44)Sc is a positron emitter with a half life of 3.92 h. Hence it could be used for PET imaging with ligands requiring longer observation time than in the case of (68)Ga.The binding affinity of (nat)Sc-DOTA-BN[2-14]NH(2) and (nat)Ga-DOTA-BN[2-14]NH(2) to GRP receptors was studied in competition to [(125)I-Tyr(4)]-Bombesin in the human prostate cancer cell line PC-3. A preliminary biodistribution in normal rats was performed, while first microPET images were assessed in male Copenhagen rats bearing the androgen-independent Dunning R-3327-AT-1 prostate cancer tumor.The …

Development of a [177Lu]BPAMD Labeling Kit and an Automated Synthesis Module for Routine Bone Targeted Endoradiotherapy

2015

Painful bone lesions, both benign and metastatic, are often managed using conventional analgesics. However, the treatment response is not immediate and is often associated with side-effects. Radionuclide therapy is used for pain palliation in bone metastases as well as some benign neoplasms. Endoradiotherapy has direct impact on the pain-producing bone elements, and hence, response is significant, with minimal or no side-effects. A new potential compound for endoradiotherapy is [(177)Lu]BPAMD. It combines a highly affine bisphosphonate, covalently bridged with DOTA through an amide bond, with the low-energy β(-) emitting therapeutic radiolanthanide (177)Lu. For routine chemical application,…

A DOTA based bisphosphonate with an albumin binding moiety for delayed body clearance for bone targeting

2016

Radiolabeled bisphosphonates are commonly used in the diagnosis and therapy of bone metastases. Blood clearance of bisphosphonates is usually fast and only 30%-50% of the injected activity is retained in the skeleton, while most of the activity is excreted by the urinary tract. A longer blood circulation may enhance accumulation of bisphosphonate compounds in bone metastases. Therefore, a chemically modified macrocyclic bisphosphonate derivative with an additional human albumin binding entity was synthesized and pharmacokinetics of its complex was evaluated. The DOTA-bisphosphonate conjugate BPAMD was compared against the novel DOTAGA-derived albumin-binding bisphosphonate DOTAGA(428-d-Lys)…

[Gadolinium-containing contrast agents: Gadoterat-meglumine is safe in patients with chronic renal failure].

2014

Objective To prospectively compare the renal safety of meglumine gadoterate (Gd-DOTA)-enhanced magnetic resonance imaging (MRI) to a control group (unenhanced MRI) in high-risk patients. Methods Patients with chronic kidney disease (CKD) scheduled for MRI procedures were screened. The primary endpoint was the percentage of patients with an elevation of serum creatinine levels, measured 72 ± 24 h after the MRI procedure, by at least 25 % or 44.2 μmol/l (0.5 mg/dl) from baseline. A non-inferiority margin of the between-group difference was set at −15 % for statistical analysis of the primary endpoint. Main secondary endpoints were the variation in serum creatinine and eGFR values between base…