Cu loaded liposome for tumor imaging using PET. (a) Remote loading of 64Cu into preformed liposomes using an ionophore, 2-hydroxyquinoline. Over 99% of encapsulation efficiency was obtained with size exclusion chromatography after a remote loading method. (b) Coronal PET image 24 hrs post-injection of 64Cu-liposomes into a mouse bearing colon adenocarcinoma (marked with arrows) on right and left flank. (Adapted with permission from Ref. 24. Copyright (2011) Elsevier).