title: Implementation of P22 viral capsids as intravascular magnetic resonance T1 contrast conjugates via site-selective attachment of Gd(III)-chelating agents.
abstract: P22 viral capsids and ferritin protein cages are utilized as templating macromolecules to conjugate Gd(III)-chelating agent complexes, and we systematically investigates the effects of the macromolecules' size and the conjugation positions of Gd(III)-chelating agents on the magnetic resonance (MR) relaxivities and the resulting image contrasts. The relaxivity values of the Gd(III)-chelating agent-conjugated P22 viral capsids (outer diameter: 64 nm) are dramatically increased as compared to both free Gd(III)-chelating agents and Gd(III)-chelating agent-conjugated ferritins (outer diameter: 12 nm), suggesting that the large sized P22 viral capsids exhibit a much slower tumbling rate, which results in a faster T1 relaxation rate. Gd(III)-chelating agents are attached to either the interior or exterior surface of P22 viral capsids and the conjugation positions of Gd(III)-chelating agents, however, do not have a significant effect on the relaxivity values of the macromolecular conjugates. The contrast enhancement of Gd(III)-chelating agent-conjugated P22 viral capsids is confirmed by in vitro phantom imaging at a short repetition times (TR) and the potential usage of Gd(III)-chelating agent-conjugated P22 viral capsids for in vivo MR imaging is validated by visualizing a mouse's intravascular system, including the carotid, mammary arteries, the jugular vein, and the superficial vessels of the head at an isotropic resolution of 250 μm.
authors.affiliation: School of Nano-Bioscience and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 689-798, Korea.
authors.forename: Junseon
authors.initials: J
authors.lastname: Min
authors.forename: Hoesu
authors.initials: H
authors.lastname: Jung
authors.forename: Hyun-Hee
authors.initials: HH
authors.lastname: Shin
authors.forename: Gyunggoo
authors.initials: G
authors.lastname: Cho
authors.forename: HyungJoon
authors.initials: H
authors.lastname: Cho
authors.forename: Sebyung
authors.initials: S
authors.lastname: Kang
mesh_terms: D000818:Animals; D017100:Bacteriophage P22; D001808:Blood Vessels / Q000033:anatomy & histology*; D002213:Capsid; D002614:Chelating Agents / Q000737:chemistry; D003287:Contrast Media / Q000737:chemistry*; D005293:Ferritins / Q000737:chemistry; D005682:Gadolinium / Q000737:chemistry; D008279:Magnetic Resonance Imaging / Q000379:methods*; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude
chemical_list: D002614:Chelating Agents; D003287:Contrast Media; D005293:Ferritins; D005682:Gadolinium