Technical Report abstract

Nature Medicine 13, 504 - 509 (2007)
Published online: 11 March 2007 | doi:10.1038/nm1522

Molecular imaging of VEGF receptors in angiogenic vasculature with single-chain VEGF-based probes

Marina V Backer1, Zoya Levashova2, Vimalkumar Patel1, Brian T Jehning1, Kevin Claffey3, Francis G Blankenberg2 & Joseph M Backer1

We describe a new generation of protein-targeted contrast agents for multimodal imaging of the cell-surface receptors for vascular endothelial growth factor (VEGF). These receptors have a key role in angiogenesis and are important targets for drug development. Our probes are based on a single-chain recombinant VEGF expressed with a cysteine-containing tag that allows site-specific labeling with contrast agents for near-infrared fluorescence imaging, single-photon emission computed tomography or positron emission tomography. These probes retain VEGF activities in vitro and undergo selective and highly specific focal uptake into the vasculature of tumors and surrounding host tissue in vivo. The fluorescence contrast agent shows long-term persistence and co-localizes with endothelial cell markers, indicating that internalization is mediated by the receptors. We expect that multimodal imaging of VEGF receptors with these probes will be useful for clinical diagnosis and therapeutic monitoring, and will help to accelerate the development of new angiogenesis-directed drugs and treatments.

  1. SibTech, Inc., 705 North Mountain Road, Newington, Connecticut 06111, USA.
  2. Department of Pediatrics & Division of Nuclear Medicine/Department of Radiology & MIPS (Molecular Imaging Program at Stanford), Stanford University, 300 Pasteur Drive, Palo Alto, California 94304, USA.
  3. University of Connecticut, Health Center, 263 Farmington Avenue, Farmington, Connecticut 06030, USA.

Correspondence to: Joseph M Backer1 e-mail:


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