title: Dextran coated bismuth-iron oxide nanohybrid contrast agents for computed tomography and magnetic resonance imaging.
abstract: Bismuth nanoparticles have been proposed as a novel CT contrast agent, however few syntheses of biocompatible bismuth nanoparticles have been achieved. We herein report the synthesis of composite bismuth-iron oxide nanoparticles (BION) that are based on a clinically approved, dextran-coated iron oxide formulation; the particles have the advantage of acting as contrast agents for both CT and MRI. BION were synthesized and characterized using various analytical methods. BION CT phantom images revealed that the X-ray attenuation of the different formulations was dependent upon the amount of bismuth present in the nanoparticle, while T2-weighted MRI contrast decreased with increasing bismuth content. No cytotoxicity was observed in Hep G2 and BJ5ta cells after 24 hours incubation with BION. The above properties, as well as the yield of synthesis and bismuth inclusion efficiency, led us to select the Bi-30 formulation forin vivoexperiments, performed in mice using a micro-CT and a 9.4 T MRI system. X-ray contrast was observed in the heart and blood vessels over a 2 hour period, indicating that Bi-30 has a prolonged circulation half-life. Considerable signal loss in T2-weighted MR images was observed in the liver compared to pre-injection scans. Evaluation of the biodistribution of Bi-30 revealed that bismuth is excreted via the urine, with significant concentrations found in the kidneys and urine.In vitroexperiments confirmed the degradability of Bi-30. In summary, dextran coated BION are biocompatible, biodegradable, possess strong X-ray attenuation properties and also can be used as T2-weighted MR contrast agents.
authors.affiliation: Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Pratap C
authors.initials: PC
authors.lastname: Naha
authors.affiliation: Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Ajlan Al
authors.initials: AA
authors.lastname: Zaki
authors.affiliation: Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Hecht
authors.affiliation: Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Chorny
authors.affiliation: Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA ; Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Chhour
authors.affiliation: Small Animal Imaging Facility, University of Pennsylvania, PA, USA.
authors.forename: Eric
authors.initials: E
authors.lastname: Blankemeyer
authors.affiliation: Nanoscale Characterization Facility, University of Pennsylvania, PA, USA.
authors.forename: Douglas M
authors.initials: DM
authors.lastname: Yates
authors.affiliation: Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA ; Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA ; Division of Cardiovascular Medicine, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Walter R T
authors.initials: WR
authors.lastname: Witschey
authors.affiliation: Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA ; Division of Cardiovascular Medicine, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Harold I
authors.initials: HI
authors.lastname: Litt
authors.affiliation: Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Tsourkas
authors.affiliation: Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA ; Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA ; Division of Cardiovascular Medicine, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: David P
authors.initials: DP
authors.lastname: Cormode
keywords: Bismuth; computed tomography; contrast agent; iron oxide; magnetic resonance imaging; nanoparticle