PFPE-Based Polymeric 19F MRI Agents: A New Class of Contrast Agents with Outstanding Sensitivity

Abstract

19F magnetic resonance imaging (MRI) is a powerful noninvasive imaging technique with demonstrated potential for the detection of important diseases. The major challenge in the design of 19F MRI agents is signal attenuation caused by the reduced solubility and segmental mobility of probes with high numbers of fluorine atoms. Careful choice of the fluorinated moiety is required to maintain image quality at the fluorine contents required for high imaging sensitivity. Here we report the synthesis of perfluoropolyether (PFPE) end-functionalized homopolymers of oligo(ethylene glycol) methyl ether acrylate (poly(OEGA)m-PFPE) as highly sensitive 19F MRI contrast agents (CAs). The structural characteristics, conformation and aggregation behavior, 19F NMR relaxation properties, and 19F MR imaging were studied in detail. Dynamic light scattering and molecular dynamics (MD) simulations were conducted and demonstrated that poly(OEGA)m-PFPE with the longest poly(OEGA)m segments (m = 20) undergoes single-chain folding ...