Development of a homotrimeric PSMA radioligand based on the NOTI chelating platform.

Background: The NOTI chelating scaffold can readily be derivatized for bioconjugation without impacting its metal complexation/radiolabeling properties making it an attractive building block for the development of multimeric/-valent radiopharmaceuticals. The objective of the study was to further explore the potential of the NOTI chelating platform by preparing and characterizing homotrimeric PSMA radioconjugates in order to identify a suitable candidate for clinical translation.

Results: Altogether, three PSMA conjugates based on the NOTI-TVA scaffold with different spacer entities between the chelating unit and the Glu-CO-Lys PSMA binding motif were readily prepared by solid phase-peptide chemistry.

Radiochemistry and Complex Formation of the Cyclen-Derived Chelator DOTI-Me with Mn, Cu, Zn, Ga, In, Tb, and Lu.

In this work, we describe the complex formation and radiochemistry of the cyclen-based chelator DOTI-Me bearing four methylimidazole arms. Radiolabeling properties were evaluated for Mn, Cu, Ga, In, Tb, and Lu, and DOTI-Me showed distinct differences to the structurally related HDOTA. While radiochemical conversions (RCCs) for Mn and In were comparable to those of HDOTA, DOTI-Me was not suited for Ga.

Diamond sensors for hard X-ray energy and position resolving measurements at the European XFEL.

The diagnostics of X-ray beam properties has a critical importance at the European X-ray Free-Electron Laser facility. Besides existing diagnostic components, utilization of a diamond sensor was proposed to achieve radiation-hard, non-invasive beam position and pulse energy measurements for hard X-rays. In particular, with very hard X-rays, diamond-based sensors become a useful complement to gas-based devices which lose sensitivity due to significantly reduced gas cross-sections.

New Constraint for Isotropic Lorentz Violation from LHC Data.

New calculations for the kinematics of photon decay to fermions in vacuo under an isotropic violation of Lorentz invariance (LV), parametrized by the standard-model extension, are presented in this Letter and used to interpret prompt photon production in LHC data. The measurement of inclusive prompt photon production at the LHC Run 2, with photons observed up to a transverse energy of 2.5 TeV, provides the lower bound κ[over ˜]_{tr}>-1.

Radiometal Complexes as Pharmacokinetic Modifiers: A Potent Ga-Labeled Gastrin-Releasing Peptide Receptor Antagonist Based on the Macrocyclic Metal Chelator NODIA-Me.

The gastrin-releasing peptide receptor (GRPr) is overexpressed in various cancer types including prostate and breast carcinomas, making it an attractive target for molecular imaging and therapy. In this work, we designed a novel GRPr antagonistic probe comprising metal chelator NODIA-Me. This 1,4,7-triazacyclononane-based chelator forms positively charged metal complexes due to its neutral methylimidazole arms.