Sonothrombolysis with Magnetically Targeted Microbubbles.

Abstract

Microbubble-enhanced sonothrombolysis is a promising approach to increasing the tolerability and efficacy of current pharmacological treatments for ischemic stroke. Maintaining therapeutic concentrations of microbubbles and drugs at the clot site, however, poses a challenge. The objective of this study was to investigate the effect of magnetic microbubble targeting upon clot lysis rates in vitro. Retracted whole porcine blood clots were placed in a flow phantom of a partially occluded middle cerebral artery. The clots were treated with a combination of tissue plasminogen activator (0.75 µg/mL), magnetic microbubbles (∼107 microbubbles/mL) and ultrasound (0.5 MHz, 630-kPa peak rarefactional pressure, 0.2-Hz pulse repetition frequency, 2% duty cycle). Magnetic targeting was achieved using a single permanent magnet (0.08-0.38 T and 12-140 T/m in the region of the clot). The change in clot diameter was measured optically over the course of the experiment. Magnetic targeting produced a threefold average increase in lysis rates, and linear correlation was observed between lysis rate and total energy of acoustic emissions.

• Authors: Marie de Saint Victor, Lester C Barnsley, Dario Carugo, Joshua Owen, Constantin C Coussios, Eleanor Stride
• Journal: Ultrasound in medicine & biology (Ultrasound Med Biol) Vol. 45 Issue 5 Pg. 1151-1163 (05 2019) ISSN: 1879-291X [Electronic] England
• PMID: 30773375 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.

Chemical References

• Fibrinolytic Agents
• Tissue Plasminogen Activator

Topics

• Animals
• Disease Models, Animal
• Fibrinolytic Agents (administration & dosage)
• In Vitro Techniques
• Microbubbles
• Swine
• Thrombolytic Therapy (methods)
• Thrombosis (therapy)
• Tissue Plasminogen Activator (administration & dosage)
• Ultrasonic Therapy (methods)