title: Oligoethylenimine-grafted chitosan as enhanced T1 contrast agent for in vivo targeted tumor MRI.
abstract: To synthesize and characterize an effective macromolecular magnetic resonance imaging (MRI) contrast agent based on oligoethylenimine-grafted chitosan with targeting capability.
  
  
  
  In this study we synthesized and characterized oligoethylenimine-grafted chitosan copolymers, followed by conjugating with Gd-DTPA and folic acid. The toxicity was evaluated by WST assay, and in vitro MRI studies were performed in comparison with Gd-DTPA. Finally, the contrast enhancement of the new macromolecular MRI contrast agent was then evaluated in the mice bearing KB xenografts.
  
  
  
  Compared to Gd-DTPA (4.3 mM(-1) s(-1) ), this macromolecular contrast agent (mCA) exhibited much higher T1 relaxivity (14.4 mM(-1) s(-1) ), up to 3.3 times higher. Meanwhile, the WST assay illustrated that the viability of KB cells remained at 90% even when the Gd concentration was 1 mM. During the in vivo study, the image contrast produced by FA-mCA was higher than one produced by mCA, up to 2.5 times higher.
  
  
  
  Our results showed this macromolecular contrast agent has potential for developing sensitive and biocompatible MRI probe with targeting capability. J. Magn. Reson. Imaging 2016;44:23-29.
authors.affiliation: Key Laboratory of Nano-Bio Interface, Divisions of Nanobiomedicine and Nanobionics, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, China.|University of Chinese Academy of Sciences, Beijing, China.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Tong
authors.affiliation: Key Laboratory of Nano-Bio Interface, Divisions of Nanobiomedicine and Nanobionics, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, China.
authors.forename: Min
authors.initials: M
authors.lastname: Liu
authors.affiliation: Key Laboratory of Nano-Bio Interface, Divisions of Nanobiomedicine and Nanobionics, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, China.
authors.forename: Kunchi
authors.initials: K
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Nano-Bio Interface, Divisions of Nanobiomedicine and Nanobionics, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Cao
authors.affiliation: Key Laboratory of Nano-Bio Interface, Divisions of Nanobiomedicine and Nanobionics, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, China.
authors.forename: Jingjin
authors.initials: J
authors.lastname: Dong
authors.affiliation: Key Laboratory of Nano-Bio Interface, Divisions of Nanobiomedicine and Nanobionics, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Jiang
authors.affiliation: Department of Pharmaceutical Engineering, School of Chemical Engineering, Wuhan University of Technology, Wuhan, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Lu
authors.affiliation: Department of Pharmaceutical Engineering, School of Chemical Engineering, Wuhan University of Technology, Wuhan, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Zheng
authors.affiliation: Key Laboratory of Nano-Bio Interface, Divisions of Nanobiomedicine and Nanobionics, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, China.
authors.forename: Hailu
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Nano-Bio Interface, Divisions of Nanobiomedicine and Nanobionics, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, China.
authors.forename: Renjun
authors.initials: R
authors.lastname: Pei
mesh_terms: D000818:Animals; D001388:Aziridines / Q000737:chemistry; D045744:Cell Line, Tumor; D048271:Chitosan / Q000737:chemistry*; D003287:Contrast Media / Q000138:chemical synthesis; D058973:Folate Receptors, GPI-Anchored / Q000378:metabolism*; D005492:Folic Acid / Q000737:chemistry / Q000493:pharmacokinetics*; D019786:Gadolinium DTPA / Q000737:chemistry / Q000493:pharmacokinetics*; D007089:Image Enhancement / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D051379:Mice; D008819:Mice, Nude; D015336:Molecular Probe Techniques; D009374:Neoplasms, Experimental / Q000000981:diagnostic imaging* / Q000378:metabolism* / Q000473:pathology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D001388:Aziridines; D003287:Contrast Media; D058973:Folate Receptors, GPI-Anchored; C033132:aziridine; D048271:Chitosan; D005492:Folic Acid; D019786:Gadolinium DTPA
keywords: chitosan; macromolecular contrast agent; oligoethylenimine; targeted tumor imaging