title: The Label Matters: μPET Imaging of the Biodistribution of Low Molar Mass89Zr and18F-Labeled Poly(2-ethyl-2-oxazoline).
abstract: Poly(2-alkyl-2-oxazoline)s (PAOx) have received increasing interest for biomedical applications. Therefore, it is of fundamental importance to gain an in-depth understanding of the biodistribution profile of PAOx. We report the biodistribution of poly(2-ethyl-2-oxazoline) (PEtOx) with a molar mass of 5 kDa radiolabeled with PET isotopes89Zr and18F.18F-labeled PEtOx is prepared by the strain-promoted azide-alkyne cycloaddition (SPAAC) of [18F]fluoroethylazide to bicyclo[6.1.0]non-4-yne (BCN)-functionalized PEtOx as many common labeling strategies were found to be unsuccessful for PEtOx.89Zr-labeled PEtOx is prepared using desferrioxamine end-groups as a chelator. Five kDa PEtOx shows a significantly faster blood clearance compared to PEtOx of higher molar mass while uptake in the liver is lower, indicating a minor contribution of the liver in excretion of the 5 kDa PEtOx. While [18F]-PEtOx displays a rapid and efficient clearance from the kidneys, 5 kDa [89Zr]-Df-PEtOx is not efficiently cleared over the time course of the study, which is most likely caused by trapping of89Zr-labeled metabolites in the renal tubules and not the polymer itself, demonstrating the importance of selecting the appropriate label for biodistribution studies.
authors.affiliation: Supramolecular Chemistry Group, Department of Organic and Macromolecular Chemistry, Ghent University , Krijgslaan 281-S4, 9000 Ghent, Belgium.
authors.forename: Mathias
authors.identifier: 0000-0003-3245-5109
authors.initials: M
authors.lastname: Glassner
authors.affiliation: Antwerp University Hospital , Department of Nuclear Medicine, Wilrijkstraat 10, B-2650 Edegem, Belgium.|Molecular Imaging Center Antwerp, University of Antwerp , Campus Drie Eiken, Universiteitsplein 1, B-2610 Wilrijk, Belgium.
authors.forename: Luca
authors.initials: L
authors.lastname: Palmieri
authors.affiliation: Supramolecular Chemistry Group, Department of Organic and Macromolecular Chemistry, Ghent University , Krijgslaan 281-S4, 9000 Ghent, Belgium.
authors.forename: Bryn D
authors.initials: BD
authors.lastname: Monnery
authors.affiliation: Antwerp University Hospital , Department of Nuclear Medicine, Wilrijkstraat 10, B-2650 Edegem, Belgium.
authors.forename: Thomas
authors.initials: T
authors.lastname: Verbrugghen
authors.affiliation: Antwerp University Hospital , Department of Nuclear Medicine, Wilrijkstraat 10, B-2650 Edegem, Belgium.
authors.forename: Steven
authors.initials: S
authors.lastname: Deleye
authors.affiliation: Antwerp University Hospital , Department of Nuclear Medicine, Wilrijkstraat 10, B-2650 Edegem, Belgium.|Molecular Imaging Center Antwerp, University of Antwerp , Campus Drie Eiken, Universiteitsplein 1, B-2610 Wilrijk, Belgium.
authors.forename: Sigrid
authors.initials: S
authors.lastname: Stroobants
authors.affiliation: Molecular Imaging Center Antwerp, University of Antwerp , Campus Drie Eiken, Universiteitsplein 1, B-2610 Wilrijk, Belgium.
authors.forename: Steven
authors.initials: S
authors.lastname: Staelens
authors.affiliation: Antwerp University Hospital , Department of Nuclear Medicine, Wilrijkstraat 10, B-2650 Edegem, Belgium.|Molecular Imaging Center Antwerp, University of Antwerp , Campus Drie Eiken, Universiteitsplein 1, B-2610 Wilrijk, Belgium.
authors.forename: Leonie
authors.initials: L
authors.lastname: Wyffels
authors.affiliation: Supramolecular Chemistry Group, Department of Organic and Macromolecular Chemistry, Ghent University , Krijgslaan 281-S4, 9000 Ghent, Belgium.
authors.forename: Richard
authors.identifier: 0000-0001-7398-2058
authors.initials: R
authors.lastname: Hoogenboom
mesh_terms: D000818:Animals; D005462:Fluorine Radioisotopes / Q000737:chemistry / Q000493:pharmacokinetics*; D007091:Image Processing, Computer-Assisted; D008099:Liver / Q000000981:diagnostic imaging* / Q000378:metabolism; D008657:Metabolic Clearance Rate; D051379:Mice; D008810:Mice, Inbred C57BL; D011073:Polyamines / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry / Q000493:pharmacokinetics; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000737:chemistry / Q000493:pharmacokinetics*; D014018:Tissue Distribution; D015040:Zirconium / Q000737:chemistry / Q000493:pharmacokinetics*
chemical_list: D005462:Fluorine Radioisotopes; D011073:Polyamines; D011108:Polymers; D019275:Radiopharmaceuticals; C511916:poly(2-ethyl-2-oxazoline); D015040:Zirconium