Monooxorhenium(V) complexes with 222-NS MAMA ligands for bifunctional chelator agents: Syntheses and preliminary in vivo evaluation.

Introduction: Targeted radiotherapy using the bifunctional chelate approach with Re(V) is challenging because of the susceptibility of monooxorhenium(V)-based complexes to oxidize in vivo at high dilution. A monoamine-monoamide dithiol (MAMA)-based bifunctional chelating agent was evaluated with both rhenium and technetium to determine its utility for in vivo applications.

Methods: A 222-MAMA chelator, 222-MAMA(N-6-Ahx-OEt) bifunctional chelator, and 222-MAMA(N-6-Ahx-BBN(7-14)NH) were synthesized, complexed with rhenium, radiolabeled with Tc and Re (carrier added and no carrier added), and evaluated in initial biological distribution studies.