This Article Full Text Full Text (PDF) All Versions of this Article: 117/25/3206    most recent CIRCULATIONAHA.107.757120v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Google Scholar Articles by Briley-Saebo, K. C. Articles by Fayad, Z. A. PubMed PubMed Citation Articles by Briley-Saebo, K. C. Articles by Fayad, Z. A. Related Collections Lipid and lipoprotein metabolism Cardiovascular imaging agents/Techniques CT and MRI Pathophysiology Related Article

(Circulation. 2008;117:3206-3215.)
© 2008 American Heart Association, Inc.

Imaging

Targeted Molecular Probes for Imaging Atherosclerotic Lesions With Magnetic Resonance Using Antibodies That Recognize Oxidation-Specific Epitopes

Karen C. Briley-Saebo, PhD; Peter X. Shaw, PhD; Willem J.M. Mulder, PhD; Seung-Hyuk Choi, MD; Esad Vucic, MD; Juan Gilberto S. Aguinaldo, MD; Joseph L. Witztum, MD; Valentin Fuster, MD, PhD; Sotirios Tsimikas, MD^*; Zahi A. Fayad, PhD^*

From the Imaging Science Laboratory, Department of Radiology (K.C.B.-S., W.M., E.V., J.G.S.A., Z.A.F.) and Department of Cardiology, Zena and Michael A. Weiner Cardiovascular Institute, and Marie-Josee and Henry R. Kravis Cardiovascular Health Center (V.F., Z.A.F.), Mount Sinai School of Medicine, New York, NY; Vascular Medicine Program, University of California, San Diego (P.X.S., S.-H.C., J.L.W., S.T.); and Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea (S.-H.C.).

Correspondence to Zahi A. Fayad, Mount Sinai School of Medicine, Imaging Science Laboratory, One Gustave Levy Place, PO Box 1234, New York, NY 10029 (e-mail zahi.fayad{at}mssm.edu); or Sotirios Tsimikas, Vascular Medicine Program, University of California San Diego, 9500 Gilman Dr, La Jolla, CA 92993–0682 (e-mail stsimikas@ucsd.edu).

Received November 30, 2007; accepted April 2, 2008.

Background— Oxidized low-density lipoprotein plays a key role in the initiation, progression, and destabilization of atherosclerotic plaques and is present in macrophages and the lipid pool. The aim of this study was to assess the feasibility of magnetic resonance imaging of atherosclerotic lesions in mice using micelles containing gadolinium and murine (MDA2 and E06) or human (IK17) antibodies that bind unique oxidation-specific epitopes.

Methods and Results— MDA2 micelles, E06 micelles, IK17 micelles, nonspecific IgG micelles, and untargeted micelles (no antibody) were prepared and characterized with respect to pharmacokinetics and biodistribution in wild-type and atherosclerotic apolipoprotein E–deficient (apoE^–/–) mice. Magnetic resonance imaging was performed at 9.4 T over a 96-hour time interval after the administration of 0.075–mmol Gd/kg micelles. MDA2, E06, and IK17 micelles exhibited a longer plasma half-life than IgG or untargeted micelles in apoE^–/– but not wild-type mice. In apoE^–/– mice, MDA2 and IK17 micelles showed maximal arterial wall uptake at 72 hours and E06 micelles at 96 hours, manifested by 125% to 231% enhancement in magnetic resonance signal compared with adjacent muscle. Confocal microscopy revealed that MDA2, IK17, and E06 micelles accumulated within atherosclerotic lesions and specifically within macrophages. Intravenous injection of free MDA2 before imaging with MDA2 micelles resulted in significantly diminished magnetic resonance signal enhancement. IgG micelles and untargeted micelles showed minimal enhancement in apoE^–/– mice. There was no significant signal enhancement with all micelles in wild-type mice.

Conclusions— Magnetic resonance imaging with micelles containing gadolinium and oxidation-specific antibodies demonstrates specific targeting and excellent image quality of oxidation-rich atherosclerotic lesions.

---

 

CLINICAL PERSPECTIVE

Related Article:

Clinical Summaries
Circulation 2008 117: 3161-3162. [Full Text]