title: A xenon-based molecular sensor assembled on an MS2 viral capsid scaffold.
abstract: In MRI, anatomical structures are most often differentiated by variations in their bulk magnetic properties. Alternatively, exogenous contrast agents can be attached to chemical moieties that confer affinity to molecular targets; the distribution of such contrast agents can be imaged by magnetic resonance. Xenon-based molecular sensors are molecular imaging agents that rely on the reversible exchange of hyperpolarized xenon between the bulk and a specifically targeted host-guest complex. We have incorporated approximately 125 xenon sensor molecules in the interior of an MS2 viral capsid, conferring multivalency and other properties of the viral capsid to the sensor molecule. The resulting signal amplification facilitates the detection of sensor at 0.7 pM, the lowest to date for any molecular imaging agent used in magnetic resonance. This amplification promises the detection of chemical targets at much lower concentrations than would be possible without the capsid scaffold.
authors.affiliation: College of Chemistry, University of California, Berkeley, Berkeley, California 94720, USA.
authors.forename: Tyler
authors.initials: T
authors.lastname: Meldrum
authors.forename: Kristen L
authors.initials: KL
authors.lastname: Seim
authors.forename: Vikram S
authors.initials: VS
authors.lastname: Bajaj
authors.forename: Krishnan K
authors.initials: KK
authors.lastname: Palaniappan
authors.forename: Wesley
authors.initials: W
authors.lastname: Wu
authors.forename: Matthew B
authors.initials: MB
authors.lastname: Francis
authors.forename: David E
authors.initials: DE
authors.lastname: Wemmer
authors.forename: Alexander
authors.initials: A
authors.lastname: Pines
mesh_terms: D002213:Capsid / Q000737:chemistry*; D003287:Contrast Media / Q000737:chemistry*; D017909:Levivirus / Q000737:chemistry*; D008279:Magnetic Resonance Imaging; D014979:Xenon Isotopes / Q000737:chemistry*
chemical_list: D003287:Contrast Media; D014979:Xenon Isotopes