title: Molecular imaging with nucleic acid aptamers.
abstract: With many desirable properties such as ease of synthesis, small size, lack of immunogenicity, and versatile chemistry, aptamers represent a class of targeting ligands that possess tremendous potential in molecular imaging applications. Non-invasive imaging of various disease markers with aptamer-based probes has many potential clinical applications such as lesion detection, patient stratification, treatment monitoring, etc. In this review, we will summarize the current status of molecular imaging with aptamer-based probes. First, fluorescence imaging will be described which include both direct targeting and activatable probes. Next, we discuss molecular magnetic resonance imaging and targeted ultrasound investigations using aptamer-based agents. Radionuclide-based imaging techniques (single-photon emission computed tomography and positron emission tomography) will be summarized as well. In addition, aptamers have also been labeled with various tags for computed tomography, surface plasmon resonance, dark-field light scattering microscopy, transmission electron microscopy, and surface-enhanced Raman spectroscopy imaging. Among all molecular imaging modalities, no single modality is perfect and sufficient to obtain all the necessary information for a particular question. Thus, a multimodality probe has also been constructed for concurrent fluorescence, gamma camera, and magnetic resonance imaging in vivo. Although the future of aptamer-based molecular imaging is becoming increasingly bright and many proof-of-principle studies have already been reported, much future effort needs to be directed towards the development of clinically translatable aptamer-based imaging agents which will eventually benefit patients.
authors.affiliation: Department of Radiology, University of Wisconsin-Madison, 1111 Highland Ave, Madison, WI 53705-2275, USA.
authors.forename: H
authors.initials: H
authors.lastname: Hong
authors.forename: S
authors.initials: S
authors.lastname: Goel
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
authors.forename: W
authors.initials: W
authors.lastname: Cai
mesh_terms: D000818:Animals; D052157:Aptamers, Nucleotide / Q000737:chemistry / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D057054:Molecular Imaging / Q000379:methods*
chemical_list: D052157:Aptamers, Nucleotide