Pharmacological Characterization of Low-to-Moderate Affinity Opioid Receptor Agonists and Brain Imaging with F-Labeled Derivatives in Rats.

The 3,4-dichloro--(1-(dimethylamino)cyclohexyl)methyl benzamide scaffold was studied as a template for F-positron emission tomography (F-PET) radiotracer development emphasizing sensitivity to changes in opioid receptor (OR) occupancy over high affinity. Agonist potency, binding affinity, and relevant pharmacological parameters of 15 candidates were investigated. Two promising compounds and with μ-OR (MOR) selective agonist activity in the moderate range (EC = 1-100 nM) were subjected to F-fluorination, autoradiography, and small-animal PET imaging.

F-labelled triazolyl-linked argininamides targeting the neuropeptide Y YR for PET imaging of mammary carcinoma.

Neuropeptide Y Y receptors (YR) have been found to be overexpressed in a number of different tumours, such as breast, ovarian or renal cell cancer. In mammary carcinoma the high YR density together with its high incidence of 85% in primary human breast cancers and 100% in breast cancer derived lymph node metastases attracted special attention. Therefore, the aim of this study was the development of radioligands for YR imaging by positron emission tomography (PET) with a special emphasis on imaging agents with reduced lipophilicity to provide a PET ligand with improved biodistribution in comparison with previously published tracers targeting the YR.

Improved radiosynthesis and preliminary in vivo evaluation of a (18)F-labeled glycopeptide-peptoid hybrid for PET imaging of neurotensin receptor 2.

The neurotensin receptor 2 (NTS2) is an attractive target for cancer imaging, as it is overexpressed in a variety of tumor types including prostate, pancreas and breast carcinoma. The aim of this study was the development of the first NTS2 subtype selective (18)F-labeled radioligand for imaging NTS2 expression in vivo by positron emission tomography (PET). The radiosynthesis of glycopeptoid (18)F-4 was realized by copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC), applying the prosthetic group 6-deoxy-6-[(18)F]fluoroglucosyl azide for (18)F-fluoroglycosylation of the alkyne-terminated NT(8-13) analog Pra-N-Me-Arg-Arg-Pro-N-homo-Tyr-Ile-Leu-OH.

Dip-in depletion optical lithography of three-dimensional chiral polarizers.

We combine the concepts of dip-in and stimulated-emission-depletion-inspired optical lithography for the first time to fabricate three-dimensional (3D) nanostructures for photonics. For depletion of the photoinitiator ITX we employ a fiber-coupled laser diode at 639 nm wavelength. To demonstrate the performance of the experimental setup, we have fabricated 3D chiral layer-by-layer twisted woodpile structures with a lattice constant reduced by more than a factor of 2 compared to earlier results.