title: Ultrasound microbubble contrast agents: fundamentals and application to gene and drug delivery.
abstract: This review offers a critical analysis of the state of the art of medical microbubbles and their application in therapeutic delivery and monitoring. When driven by an ultrasonic pulse, these small gas bubbles oscillate with a wall velocity on the order of tens to hundreds of meters per second and can be deflected to a vessel wall or fragmented into particles on the order of nanometers. While single-session molecular imaging of multiple targets is difficult with affinity-based strategies employed in some other imaging modalities, microbubble fragmentation facilitates such studies. Similarly, a focused ultrasound beam can be used to disrupt delivery vehicles and blood vessel walls, offering the opportunity to locally deliver a drug or gene. Clinical translation of these vehicles will require that current challenges be overcome, where these challenges include rapid clearance and low payload. The technology, early successes with drug and gene delivery, and potential clinical applications are reviewed.
authors.affiliation: Department of Biomedical Engineering, University of California, Davis, California 95616-8686, USA. kwferrara@ucdavis.edu
authors.forename: Katherine
authors.initials: K
authors.lastname: Ferrara
authors.forename: Rachel
authors.initials: R
authors.lastname: Pollard
authors.forename: Mark
authors.initials: M
authors.lastname: Borden
mesh_terms: D003287:Contrast Media / Q000737:chemistry / Q000627:therapeutic use*; D016503:Drug Delivery Systems / Q000379:methods*; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods*; D007089:Image Enhancement / Q000379:methods; D045423:Microbubbles; D013010:Sonication; D014463:Ultrasonography / Q000379:methods*
chemical_list: D003287:Contrast Media