Tunable in vivo circulation characteristics of PEGylated MPI tracers

Understanding the pharmacokinetic (PK) properties of MPI tracers is necessary for enabling the wide spectrum of possible in vivo MPI applications. For intravenously administered tracers, blood half-life (t_1/2) is a critical PK property that will help determine the suitability and clinical readiness for applications such as cardiovascular and molecular imaging. Here we show the ability to tune the in vivo circulation characteristics (t_1/2) of polyethylene glycol (PEG)-coated (“PEGylated”) MPI tracers. PEG is a biocompatible polymer frequently used to enhance the circulation characteristics of nanoparticles and other macromolecules such as antibodies. Results show that the blood half-life of PEGylated MPI tracers depends on the molecular weight and loading density of PEG. We show that the PMAO-PEG polymer is a versatile coating platform that gives the ability to modify and potentially tune the circulation characteristics of MPI tracers for for specific in vivo applications.