In vivo comparison of DOTA based 68Ga-labelled bisphosphonates for bone imaging in non-tumour models.

Bone metastases are a class of cancerous metastases that result from the invasion of a tumor into bone. The solid mass which forms inside the bone is often associated with a constant dull ache and severe spikes in pain, which greatly reduce the quality of life of the patient. Numerous (99m)Tc-labeled bisphosphonate functionalised complexes are well established tracers for bone metastases imaging. The objective of this research was to evaluate the pharmacokinetics and behaviour of three DOTA based bisphosphonate functionalised ligands (BPAMD, BPAPD and BPPED), using both (68)Ga μ-PET in vivo imaging and ex vivo biodistribution studies in healthy Wistar rats. The compounds were labelled with …

Bone targeting compounds for radiotherapy and imaging: *Me(III)-DOTA conjugates of bisphosphonic acid, pamidronic acid and zoledronic acid

Background Bisphosphonates have a high adsorption on calcified tissues and are commonly used in the treatment of bone disorder diseases. Conjugates of bisphosphonates with macrocyclic chelators open new possibilities in bone targeted radionuclide imaging and therapy. Subsequent to positron emission tomography (PET) examinations utilizing 68Ga-labelled analogues, endoradiotheraphy with 177Lu-labelled macrocyclic bisphosphonates may have a great potential in the treatment of painful skeletal metastases. Methods Based on the established pharmaceuticals pamidronate and zoledronate two new DOTA-α-OH-bisphosphonates, DOTAPAM and DOTAZOL(MM1.MZ) were successfully synthesized. The ligands were labe…

Synthesis, Labeling and Preclinical Evaluation of a Squaric Acid Containing PSMA Inhibitor Labeled with 68 Ga: A Comparison with PSMA‐11 and PSMA‐617

The L-lysine urea-L-glutamate (KuE) represents a key motif in recent diagnostic and therapeutic radiopharmaceuticals targeting the prostate specific membrane antigen (PSMA). Using a squaric acid moiety for coupling of KuE with a radioactive label, the squaric acid as a linker in the PSMA ligand seems to mimic the aromatic structure of the naphthylalanine unit on PSMA-617. In this work, we investigate the influence of squaric acid moiety on the biological activity of the compound carrying a KuE motif and three typical chelates. The derivatives TRAM.SA.KuE, DOTAGA.SA.KuE and NODAGA.SA.KuE were all synthesized in straightforward organic reactions and purified by HPLC afterward. Different amoun…

AAZTA5.SA.KuE, a versatile tool for theranostic application – labeling, in vitro, and first in vivo-investigation of [ 177 Lu]Lu- AAZTA 5 .SA.KuE

Novel Radiolabeled Bisphosphonates for PET Diagnosis and Endoradiotherapy of Bone Metastases.

Bone metastases, often a consequence of breast, prostate, and lung carcinomas, are characterized by an increased bone turnover, which can be visualized by positron emission tomography (PET), as well as single-photon emission computed tomography (SPECT). Bisphosphonate complexes of 99mTc are predominantly used as SPECT tracers. In contrast to SPECT, PET offers a higher spatial resolution and, owing to the 68Ge/68Ga generator, an analog to the established 99mTc generator exists. Complexation of Ga(III) requires the use of chelators. Therefore, DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid), NOTA (1,4,7-triazacyclododecane-1,4,7-triacetic acid), and their derivatives, are ofte…

68Ga- und 177Lu-markierte Bisphosphonate als Knochenmetastasen-Theranostika

Der erhohte Metabolismus der Knochenmatrix kann zum einen mit der SPECT- und zum anderen mit der PET-Technik visualisiert werden. Als SPECT-Nuklid wird uberwiegend 99 mTc in Form von [99mTc]Bisphosphonat-Komplexen verwendet. Die PET bietet im Gegensatz zur SPECT eine hohere lokale und temporale Auflosung. Mit dem 68Ge/68Ga-Generatorsystem existiert ein mittlerweile bewahrtes PET-Pendant zum etablierten 99mTc-Generator. Neuartige Bisphosphonate (BP) in Kombination mit makrozyklischen Chelatoren sind derzeit weltweit Gegenstand der Forschung. Zur Komplexierung von Ga(III) werden haufig DOTA und NOTA sowie deren Derivate verwendet. Speziell im Fall von DOTA-Derivaten bieten DOTA-BP die Moglich…

Additional file 1: of Instant kit preparation of 68Ga-radiopharmaceuticals via the hybrid chelator DATA: clinical translation of [68Ga]Ga-DATA-TOC

Table S1. Binding affinities of [natGa]Ga-DATA-TOC and [natGa]Ga-DOTA-TOC on hSST2/3/5, as determined during displacement of [125I-Tyr25]LTT-SS28 from transfected HEK293-hSST2/3/5 cell membranes; LTT-SS28 served as reference. Table S2. Uptake in terms of %IA of [68Ga]Ga-DATA-TOC or [68Ga]Ga-DOTA-TOC in selected organs of MPC-mCherry tumour-bearing female NMRI nu/nu mice 1 h p.i. (218 ± 57 MBq (11.2 nmol peptide/kg) and 441 ± 109 MBq (10.5 nmol peptide)/kg body weight, respectively; blocking after coinjection of 100 µg/mouse [Nal3]octreotide acetate)). Table S3. Radioactivity concentration in terms of SUV of [68Ga]Ga-DATA-TOC or [68Ga]Ga-DOTA-TOC in selected organs of MPC-mCherry tumour-bear…