title: Potential of gold-bound microtubules as a new ultrasound contrast agent.
abstract: Contrast agents based on gas-filled microspheres share the problem of time limited opacification due to low stability of microbubbles. The aim of this study was to test if gold-bound microtubules provide backscattering that allows microtubules to be potentially useful as an ultrasound (US) contrast agent. Gold colloids were immobilized on protein microtubule walls. Latex balloons were filled with gold-bound microtubules or conventional left heart contrast agent and were ultrasonographically imaged in fundamental and harmonic modes. Feasibility of anti-beta-tubulin antibody conjugation to gold-bound microtubules was confirmed using immune fluorescence analysis. Gold particles were successfully bound to microtubules. Contrast intensities in latex balloons filled with gold-bound microtubules (141 +/- 35) were comparable to those with Levovist (180 +/- 35) and did not decrease significantly during continuous US imaging for 20 min (135 +/- 34 vs. Levovist 5.0 +/- 2.0). Anti-beta-tubulin antibodies were successfully conjugated to gold-bound microtubules. Gold-bound microtubules provide a persistent contrast effect, suggesting their use as an ultrasonic contrast agent with the feasibility of antibody conjugation.
authors.affiliation: Department of Cardiology, University of Heidelberg, Heidelberg, Germany.
authors.forename: Raffi
authors.initials: R
authors.lastname: Bekeredjian
authors.forename: Silke
authors.initials: S
authors.lastname: Behrens
authors.forename: Johannes
authors.initials: J
authors.lastname: Ruef
authors.forename: Eckhard
authors.initials: E
authors.lastname: Dinjus
authors.forename: Eberhard
authors.initials: E
authors.lastname: Unger
authors.forename: Marina
authors.initials: M
authors.lastname: Baum
authors.forename: Helmut F
authors.initials: HF
authors.lastname: Kuecherer
mesh_terms: D000818:Animals; D003287:Contrast Media; D005740:Gases; D006046:Gold; D008863:Microspheres; D008870:Microtubules / Q000737:chemistry; D011134:Polysaccharides; D013552:Swine; D014463:Ultrasonography / Q000379:methods*
chemical_list: D003287:Contrast Media; D005740:Gases; D011134:Polysaccharides; C059891:SHU 508; D006046:Gold