Synthesis of cobalt‐55/57‐complexes for radiolabelling of platelets as a potential PET imaging agent

Abstract

AbstractComplexes of oxine, tropolone and mercaptopyridine‐N‐oxide (MPO) with 111In have been widely used for platelet labelling. The medium half‐life PET radioisotope cobalt‐55 would combine the higher sensitivity and resolution of PET with a half‐life allowing quantitative uptake and cell kinetic studies. We therefore investigated the synthesis and platelet uptake of 57Co‐oxine, 57Co‐tropolonate and 57Co‐MPO in vitro with cobalt‐57 as model for the cobalt‐55. The complexes were formed in high yields >90%, with the exception of 57Co‐tropolonate 38%, and were stable over several days. The platelet uptake was generally low with 5–13%. Thus, these complexes are not ideal for platelet labelling and the eventually following PET application. Copyright © 2001 John Wiley & Sons, Ltd.