In vivo molecular imaging of stretch-induced tissue factor in carotid arteries with ligand-targeted nanoparticles.

TLDR: It is demonstrated that this novel nanoemulsion can infiltrate into arterial walls after balloon injury and localize the expression of overstretch-induced tissue factor within pig carotid arteries.

Abstract: Molecular imaging permits tissues to be functionally characterized by identification of specific cell-surface receptors with targeted contrast agents. In our study, a ligand-targeted acoustic nanoparticle system was used to identify the angioplasty-induced expression of tissue factor by smooth muscle cells within the tunica media. Pig carotid arteries were overstretched bilaterally with balloon catheters, treated with a tissue factor–targeted or a control nanoparticle system, and imaged with intravascular ultrasound (20 MHz) before and after treatment. Carotid wall acoustic reflectivities were unaffected by overstretch injury. Tissue factor–targeted nanoemulsion bound and increased the echogenicity of smooth muscle cells expressing tissue factor within the tunica media. The targeted emulsion increased the arterial wall gray scale (99.4 ± 14.5; P P P