The efficiency of 18F labelling of a prostate specific membrane antigen ligand via strain-promoted azide–alkyne reaction: reaction speed versus hydrophilicity

Abstract

Here we report the ¹⁸F labeling of a prostate specific membrane antigen (PSMA) ligand via a strain promoted oxa-dibenzocyclooctyne (ODIBO)- or bicyclo[6.1.0]nonyne (BCN)-azide reaction. Although ODIBO reacts with azide 20 fold faster than BCN, in vivo PET imaging suggests that ¹⁸F-BCN-azide-PSMA demonstrated much higher tumor uptake and a much higher tumor to background contrast.