Ultrasound Thrombolysis with Magnetic Microbubbles Under a Rotational Magnetic Field

摘要

Thrombosis is a severe clinical condition that blood clot forms in a blood vessel and blocks the flow of blood through the cardiovascular system. Previous ultrasound thrombolysis methods using microbubbles often have a relatively low lysis efficiency due to the low microbubble concentration at clot region caused by blood flow in the vessel. To solve this problem, the magnetic microbubbles (microbubbles coated with 50 nm magnetic nanoparticles) that can be manipulated by a magnetic field are introduced in the study. The rationale of this study was to investigate whether magnetic microbubble can be a useful adjuvant to improve the sonothrombolysis treatment efficiency. Here we report the development of a new method using the rotational magnetic field to trap and vibrate the magnetic microbubbles at target clot region and then using an intravascular forward-looking ultrasound transducer to activate them acoustically. The in-vitro intravascular sonothrombolysis testing results indicated that by oscillating magnetic microbubbles, a vortex-like microstreaming in clot region will enhance microbubble cavitation and exhibit a higher lysis rate (1.5 ± 0.06%/min) than the previous (0.7 ± 0.15%/min)microbubble alone sonothrombolysis technique.