Preparation of targeted microbubbles: ultrasound contrast agents for molecular imaging

Med Biol Eng Comput. 2009 Aug;47(8):875-82. doi: 10.1007/s11517-009-0498-0. Epub 2009 Jun 11.


Targeted ultrasound contrast agents can be prepared by attaching targeting ligands to the lipid, protein or polymer shell coating of gas-filled microbubbles. These materials are stable on storage, fully biocompatible and can be administered parenterally. Detection of microbubble contrast agents by ultrasound is very efficient (single particles with picogram mass can be visualized). Covalent or noncovalent binding techniques can be used to attach targeting ligands. Ligand-carrying microbubbles adhere to the respective molecular targets in vitro and in vivo. Several biomechanical methods are available to improve targeting efficacy, such as the use of a flexible tether spacer arm between the ligand and the bubble, and the use of folds on the microbubble shell, that project out, enhancing the contact area and increasing the length of the lever arm.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Chemistry, Physical
  • Contrast Media / chemistry
  • Humans
  • Ligands
  • Microbubbles*
  • Molecular Imaging / methods*
  • Ultrasonography / methods


  • Contrast Media
  • Ligands