title: Producing Radical-Free Hyperpolarized Perfusion Agents for In Vivo Magnetic Resonance Using Spin-Labeled Thermoresponsive Hydrogel.
abstract: Dissolution dynamic nuclear polarization (DNP) provides a way to tremendously improve the sensitivity of nuclear magnetic resonance experiments. Once the spins are hyperpolarized by dissolution DNP, the radicals used as polarizing agents become undesirable since their presence is an additional source of nuclear spin relaxation and their toxicity might be an issue. This study demonstrates the feasibility of preparing a hyperpolarized [1-(13) C]2-methylpropan-2-ol (tert-butanol) solution free of persistent radicals by using spin-labeled thermoresponsive hydrophilic polymer networks as polarizing agents. The hyperpolarized (13) C signal can be detected for up to 5 min before the spins fully relax to their thermal equilibrium. This approach extends the applicability of spin-labeled thermoresponsive hydrogel to the dissolution DNP field and highlights its potential as polarizing agent for preparing neat slowly relaxing contrast agents. The hydrogels are especially suited to hyperpolarize deuterated alcohols which can be used for in vivo perfusion imaging.
authors.affiliation: Institute of Physics of Biological Systems, Ecole Polytechnique Fédérale de Lausanne, Station 6, 1015, Lausanne, Switzerland.
authors.forename: Tian
authors.initials: T
authors.lastname: Cheng
authors.affiliation: Laboratory for Functional and Metabolic Imaging, Ecole Polytechnique Fédérale de Lausanne, Station 6, 1015, Lausanne, Switzerland.|Center for Biomedical Imaging, Ecole Polytechnique Fédérale de Lausanne, Station 6, 1015, Lausanne, Switzerland.
authors.forename: Mor
authors.initials: M
authors.lastname: Mishkovsky
authors.affiliation: Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany.
authors.forename: Matthias J N
authors.initials: MJ
authors.lastname: Junk
authors.affiliation: Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany.|Laboratory of Engineering Thermodynamics (LTD) and Laboratory of Advanced Spin Engineering (LASE), University of Kaiserslautern, Erwin-Schrödinger-Straße 44, 67663, Kaiserslautern, Germany.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Münnemann
authors.affiliation: Institute of Physics of Biological Systems, Ecole Polytechnique Fédérale de Lausanne, Station 6, 1015, Lausanne, Switzerland.
authors.forename: Arnaud
authors.initials: A
authors.lastname: Comment
mesh_terms: D002247:Carbon Isotopes; D005609:Free Radicals; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D010477:Perfusion; D013696:Temperature; D020002:tert-Butyl Alcohol / Q000737:chemistry*
chemical_list: D002247:Carbon Isotopes; D005609:Free Radicals; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D020002:tert-Butyl Alcohol
keywords: carbon-13 MRS; dynamic nuclear polarization; radical-free; spin-labeled thermoresponsive hydrogels