Project 16

Ultrasound Contrast agents

Ultrasound contrast agents (UCA) consist of gas microbubbles (1 - 10 µm) that are coated by a protein, lipid or polymer. In addition to their diagnostic value, microbubbles have great potential as local drug delivery systems. In project 16 we investigate the clinical and the more fundamental/ future use of UCA and targeted UCA.

Upon excitation by an appropriate ultrasonic field the microbubbles start to vibrate thereby acting as an ultrasound source. This source shows a very specific signature which differs to a great extent from the scattering by normal/pathological tissue. For therapy the microbubble can be given simultaneously with the drug or loaded with the drug of choice. The drug can be locally released upon ultrasound excitation and/or the vibrating microbubble is used to enhance the uptake of the drug. Essential in this whole process is the knowledge of the vibrating bubble, the ultrasound field, and the imaging capabilities of the ultrasound system. Future use of UCA lies in ultrasound molecular imaging by using targeted microbubbles that bind to cellular disease processes. These targeted microbubbles are functionalized using specific ligands and injected into the human body.
The current therapeutic projects focus on how UCA interact with cells for locally administering high doses of drugs. The cells of interest are endothelial cells for vascular drug delivery or bacteria to treat infective endocarditis, a bacterial infection of the heart valve. Also, novel phospholipid-coated UCA are produced and characterized for theranostic (combination of therapy and diagnostic) use.

Principal InvestigatorN de Jong, K Kooiman
Co-InvestigatorsHJ Vos, AFL Schinkel, AFW van der Steen
PhD candidates DI Beekers, KR Lattwein, SAG Langeveld