Novel liver macromolecular MR contrast agent with a polypropylenimine diaminobutyl dendrimer core: Comparison to the vascular MR contrast agent with the polyamidoamine dendrimer core

✍ Scribed by Hisataka Kobayashi; Satomi Kawamoto; Tsuneo Saga; Noriko Sato; Akira Hiraga; Takayoshi Ishimori; Yukio Akita; Marcelo H. Mamede; Junji Konishi; Kaori Togashi; Martin W. Brechbiel

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: English
• Weight: 347 KB
• Volume: 46
• Category: Article
• ISSN: 0740-3194
• DOI: 10.1002/mrm.1259

✦ Synopsis

Abstract

As MRI contrast agents, more hydrophobic molecules reportedly accumulate in the liver and thus are potentially useful as liver MRI contrast agents. In this study, a generation‐4 polypropylenimine diaminobutane dendrimer (DAB‐Am64), which is expected to be more hydrophobic than the generation‐4 polyamidoamine dendrimer (PAMAM‐G4D), was used to synthesize a conjugate with 2‐(p‐isothiocyanatobenzyl)‐6‐methyl‐diethylenetriaminepentaacetic acid (1B4M) [DAB‐Am64‐(1B4M‐Gd)~64~] for complexing Gd(III) ions. This DAB conjugate quickly accumulated in the liver and its characteristics were studied and compared with those of a PAMAM conjugate [PAMAM‐G4D‐(1B4M‐Gd)~64~], which is known to be a useful vascular MRI contrast agent, in regard to its availability as a liver MRI contrast agent. DAB‐Am64‐(1B4M‐Gd)~64~ accumulated significantly more in the liver and less in blood than PAMAM‐G4D‐(1B4M‐Gd)~64~ (P < 0.001). Contrast‐enhanced MRI with DAB‐Am64‐(1B4M‐Gd)~64~ was able to homogeneously enhance liver parenchyma and visualize both portal and hepatic veins of 0.5 mm diameter in mice. In conclusion, DAB‐Am64‐(1B4M‐Gd)~64~ is a good candidate for a liver MRI contrast agent. Magn Reson Med 46:795–802, 2001. © 2001 Wiley‐Liss, Inc.