title: Segmented Highly Branched Copolymers: Rationally Designed Macromolecules for Improved and Tunable (19)F MRI.
abstract: Highly branched polymers are a promising platform for the design of next-generation contrast agents for (19)F magnetic resonance imaging (MRI). A series of segmented highly branched polymers (SHBPs) consisting of fluoro- and PEG-based monomers were synthesized by self-condensing vinyl copolymerization (SCVP) using the reversible addition-fragmentation chain transfer (RAFT) technique. SHBPs having different compositions and degrees of branching were obtained by varying the monomer type and feed ratio of monomer to chain transfer agent (CTA). The chemical structures and physical properties of the branched polymers were thoroughly characterized in detail by NMR, SEC and DSC. The systematic variation in structural parameters allowed the relationships between molecular structure, sequence distribution, and imaging performance to be examined. The (19)F NMR properties were strongly affected by the sequence distribution of the fluorinated monomers, the type of polymer backbone and the degree of branching. As a result, SHBPs consisting of statistical copolymeric segments of acrylate units were identified as excellent candidates for imaging due to a single (19)F signal, long T2 relaxation times, and high fluorine contents. The SHBPs could be all imaged or selectively imaged by taking advantage of the differences in relaxation times, demonstrating tunable and selective imaging performance through tailoring the structure and composition of the SHBPs.
authors.affiliation: Australian Institute for Bioengineering and Nanotechnology; Centre for Advanced Imaging; ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, The University of Queensland , St. Lucia, Queensland 4072, Australia.
authors.forename: Kewei
authors.initials: K
authors.lastname: Wang
authors.affiliation: Australian Institute for Bioengineering and Nanotechnology; Centre for Advanced Imaging; ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, The University of Queensland , St. Lucia, Queensland 4072, Australia.
authors.forename: Hui
authors.initials: H
authors.lastname: Peng
authors.affiliation: Australian Institute for Bioengineering and Nanotechnology; Centre for Advanced Imaging; ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, The University of Queensland , St. Lucia, Queensland 4072, Australia.
authors.forename: Kristofer J
authors.initials: KJ
authors.lastname: Thurecht
authors.affiliation: Australian Institute for Bioengineering and Nanotechnology; Centre for Advanced Imaging; ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, The University of Queensland , St. Lucia, Queensland 4072, Australia.
authors.forename: Simon
authors.initials: S
authors.lastname: Puttick
authors.affiliation: Australian Institute for Bioengineering and Nanotechnology; Centre for Advanced Imaging; ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, The University of Queensland , St. Lucia, Queensland 4072, Australia.
authors.forename: Andrew K
authors.initials: AK
authors.lastname: Whittaker
mesh_terms: D003287:Contrast Media / Q000737:chemistry*; D005462:Fluorine Radioisotopes / Q000737:chemistry*; D006845:Hydrocarbons, Fluorinated / Q000737:chemistry*; D008279:Magnetic Resonance Imaging; D011092:Polyethylene Glycols / Q000737:chemistry*
chemical_list: D003287:Contrast Media; D005462:Fluorine Radioisotopes; D006845:Hydrocarbons, Fluorinated; D011092:Polyethylene Glycols; C000595209:polyethylene glycol 1000