Molecular imaging of stretch-induced tissue factor expression in carotid arteries with intravascular ultrasound.
OBJECTIVE
Molecular imaging with targeted contrast agents enables tissues to be distinguished by detecting specific cell-surface receptors. In the present study, a ligand-targeted acoustic nanoparticle system is used to identify angioplasty-induced expression of tissue factor by smooth muscle cells within carotid arteries.


METHODS
Pig carotid arteries were overstretched with balloon catheters, treated with tissue factor-targeted or a control nanoparticle system, and imaged with intravascular ultrasound before and after treatment.


RESULTS
Tissue factor-targeted emulsions bound and increased the echogenicity and gray-scale levels of overstretched smooth muscle cells within the tunica media, versus no change in contralateral control arteries. Expression of stretch-induced tissue factor in carotid artery media was confirmed by immunohistochemistry.


CONCLUSIONS
The potential for abnormal thrombogenicity of balloon-injured arteries, as reflected by smooth muscle expression of tissue factor, was imaged using a novel, targeted, nanoparticulate ultrasonic contrast agent.
Lanza
G M
GM
Department of Medicine, Washington University Medical School, Barnes-Jewish Hospital, St. Louis, Missouri 63110, USA. greg@soundlab.wustl.edu
Abendschein
D R
DR
Hall
C S
CS
Marsh
J N
JN
Scott
M J
MJ
Scherrer
D E
DE
Wickline
S A
SA
D000818:Animals; D002339:Carotid Arteries / Q000000981:diagnostic imaging*; D002404:Catheterization; D003287:Contrast Media; D005466:Fluorocarbons; D008855:Microscopy, Electron, Scanning; D009131:Muscle, Smooth, Vascular / Q000000981:diagnostic imaging*; D013552:Swine; D013925:Thromboplastin / Q000032:analysis* / Q000378:metabolism; D014463:Ultrasonography
D003287:Contrast Media; D005466:Fluorocarbons; D013925:Thromboplastin