title: Targeted ultrasound contrast agents for ultrasound molecular imaging and therapy.
abstract: Ultrasound contrast agents (UCAs) are used routinely in the clinic to enhance contrast in ultrasonography. More recently, UCAs have been functionalised by conjugating ligands to their surface to target specific biomarkers of a disease or a disease process. These targeted UCAs (tUCAs) are used for a wide range of pre-clinical applications including diagnosis, monitoring of drug treatment, and therapy. In this review, recent achievements with tUCAs in the field of molecular imaging, evaluation of therapy, drug delivery, and therapeutic applications are discussed. We present the different coating materials and aspects that have to be considered when manufacturing tUCAs. Next to tUCA design and the choice of ligands for specific biomarkers, additional techniques are discussed that are applied to improve binding of the tUCAs to their target and to quantify the strength of this bond. As imaging techniques rely on the specific behaviour of tUCAs in an ultrasound field, it is crucial to understand the characteristics of both free and adhered tUCAs. To image and quantify the adhered tUCAs, the state-of-the-art techniques used for ultrasound molecular imaging and quantification are presented. This review concludes with the potential of tUCAs for drug delivery and therapeutic applications.
authors.affiliation: Department of Biomedical Engineering, Thoraxcenter , Erasmus MC, Rotterdam , the Netherlands .
authors.forename: Tom
authors.initials: T
authors.lastname: van Rooij
authors.forename: Verya
authors.initials: V
authors.lastname: Daeichin
authors.forename: Ilya
authors.initials: I
authors.lastname: Skachkov
authors.forename: Nico
authors.initials: N
authors.lastname: de Jong
authors.forename: Klazina
authors.initials: K
authors.lastname: Kooiman
mesh_terms: D003287:Contrast Media / Q000008:administration & dosage*; D016503:Drug Delivery Systems; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D045423:Microbubbles; D057054:Molecular Imaging / Q000379:methods*; D014464:Ultrasonic Therapy; D014463:Ultrasonography
chemical_list: D003287:Contrast Media
keywords: Drug delivery; microbubble; molecular imaging; targeted ultrasound contrast agents; therapy