Strategies for Optimized Radiolabeling of Nanoparticles for in vivo PET Imaging

Abstract

Driven by the motivation for optimizing 64 Cu radiolabeling efficiency of nanoparticles for in vivo positron emission tomography (PET) imaging, a new strategy has been developed. This strategy involved a complete redesign of the nanoparticle system, utilizing macromolecular precursors that were preloaded with labeling sites and programmed for supramolecular assembly into discrete, functional nanoscale objects. A series of shell-crosslinked nanoparticles (SCKs) have been constructed by grafting a copper chelating agent (DOTAlysine) onto amphiphilic block copolymers PAA-b-PS, self assembling the functionalized block copolymer precursors into micelles, and crosslinking the micellar corona to afford the expected nanoobjects. These pre-DOTAlysine-SCKs showed impressive results on 64 Cu radiolabeling (∼ 400 copper atoms per spherical nanoparticle). Among the molecular imaging modalities, PET is widely used as a powerful diagnostic tool by clinicians and scientists. [1] Compared with other imaging methods, it bears the advantages of high sensitivity (the level of detection approaches 10 –11 M of tracer) and isotropism (i.e., ability to detect expres