Automated radiosynthesis of [ C]UCB-J for imaging synaptic density by positron emission tomography.

An automated radiosynthesis of carbon-11 positron emission tomography radiotracer [ C]UCB-J for imaging the synaptic density biomarker synaptic vesicle glycoprotein SV2A was established using Synthra RNPlus synthesizer. Commercially available trifluoroborate UCB-J analogue was used as a radiolabelling precursor, and the desired radiolabelled product was isolated in 11 ± 2% (n = 7) nondecay corrected radiochemical yield and formulated as a 10% EtOH solution in saline with molar activities of 20 to 100 GBq/μmol. The method was based upon the palladium(0)-mediated Suzuki cross-coupling reaction and [ C]CH I as a radiolabelling synthon.

Improving the biodistribution of PSMA-targeting tracers with a highly negatively charged linker.

Background: Prostate specific membrane antigen (PSMA) is overexpressed in prostate cancer and in tumor vasculature. Small molecule based inhibitors of PSMA have promised to provide sensitive detection of primary and metastatic prostate tumors. Although significant progress has been made, many of the radiolabeled imaging agents exhibit non-specific background binding.

An alternative method for determining the radiochemical purity of 99mTc-tetrofosmin.

The instant thin-layer chromatographic method of determining the radiochemical purity of (99m)Tc-tetrofosmin recommended by the manufacturer uses a mixture of acetone and dichloromethane (35:65 v/v) as the solvent and a silica gel (SG) strip as the solid phase. Currently, SG strips are not available commercially and an alternative solid phase is needed. The present study reports that silicic acid strips are an appropriate substitute for SG strips for the chromatographic method using the same solvent mixture but mixed in a reverse ratio (65:35 v/v).

Design, synthesis, and preliminary in vitro and in vivo evaluation of N-(2-diethylaminoethyl)-4-[18F]fluorobenzamide ([18F]-DAFBA): a novel potential PET probe to image melanoma tumors.

In order to develop a PET radiopharmaceutical to image malignant melanoma, we synthesized N-(2-diethylaminoethyl)-4-[(18)F]fluorobenzamide ([(18)F]-DAFBA). In vitro studies show a high uptake of [(18)F]-DAFBA by the B16F1 melanoma cells. No significant binding was seen for DAFBA to the sigma-1 and sigma-2 receptors in vitro.

A remote controlled system for the preparation of 7 alpha-[18F]fluoro-17 alpha-methyl 5 alpha-dihydrotestosterone ([18F]FMDHT) using microwave.

For non-invasive imaging of the prostate cancer, we synthesized 7 alpha-fluoro-17 alpha-methyl 5 alpha-dihydrotestosterone ([(18)F]FMDHT) for androgen receptor mediated PET imaging. Preliminary in vitro and in vivo evaluations of this compound show promise. We designed and implemented a remote controlled system for reliable, efficient, and safe handling of radioactivity during the radiochemical synthesis of [(18)F]FMDHT.

In vivo biodistribution of an androgen receptor avid PET imaging agent 7-alpha-fluoro-17 alpha-methyl-5-alpha-dihydrotestosterone ([(18)F]FMDHT) in rats pretreated with cetrorelix, a GnRH antagonist.

Purpose: For this study, we have assessed the in vivo distribution and androgen receptor (AR) seeking properties of an F-18-labeled androgen [(18)F]FMDHT in rats castrated with a GnRH antagonist.

Materials And Methods: The radiochemical synthesis of [(18)F]FMDHT was performed using a previously published method. The radiochemical synthesis provided the desired product in good radiochemical yields and radiochemical purity.