Magnetic resonance imaging of cardiomyocyte apoptosis with a novel magneto-optical nanoparticle

✍ Scribed by David E. Sosnovik; Eyk A. Schellenberger; Matthias Nahrendorf; Mikhail S. Novikov; Takashi Matsui; George Dai; Fred Reynolds; Luanda Grazette; Anthony Rosenzweig; Ralph Weissleder; Lee Josephson

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 374 KB
• Volume: 54
• Category: Article
• ISSN: 0740-3194
• DOI: 10.1002/mrm.20617

✦ Synopsis

Abstract

The ability to image cardiomyocyte apoptosis in vivo with high‐resolution MRI could facilitate the development of novel cardioprotective therapies. The sensitivity of the novel nanoparticle AnxCLIO‐Cy5.5 for cardiomyocyte apoptosis was thus compared in vitro to that of annexin V‐FITC and showed a high degree of colocalization. MRI was then performed, following transient coronary artery (LAD) occlusion, in five mice given AnxCLIO‐Cy5.5 and in four mice given an identical dose (2 mg Fe/kg) of CLIO‐Cy5.5. MR signal intensity and myocardial T~2~* were evaluated, in vivo, in hypokinetic regions of myocardium in the LAD distribution. Ex vivo fluorescence imaging was performed to confirm the in vivo findings. Myocardial T~2~* was significantly lower in the mice given AnxCLIO‐Cy5.5 (8.1 versus 13.2 ms, P < 0.01), and fluorescence target to background ratio was significantly higher (2.1 versus 1.1, P < 0.01). This study thus demonstrates the feasibility of obtaining high‐resolution MR images of cardiomyocyte apoptosis in vivo with the novel nanoparticle, AnxCLIO‐Cy5.5. Magn Reson Med, 2005. © 2005 Wiley‐Liss, Inc.