Christy K. Holland
Ultrasound mediated drug delivery for the treatment of cardiovascular disease
Cardiovascular disease is the number one cause of death worldwide and thrombo-occlusive disease is a leading cause of morbidity and mortality. Ultrasound has been developed as both a diagnostic tool and a potent promoter of beneficial bioeffects for the treatment of cardio vascular disease. Ultrasound exposure can induce the release, delivery and en hanced efficacy of a thrombolytic drug (rt-PA), antibiotics, or bioactive gases from echogenic liposomes. By encapsulating drugs into micron-sized and nano-sized li po so mes, the therapeutic can be shielded from degradation within the vasculature until delivery is triggered by ultrasound exposure.
Microbubbles oscillate when exposed to ultrasound and create stresses directly on nearby tissue or induce fluid effects that affect drug penetration into vascular tissue, lyse thrombi or direct drugs to optimal locations for delivery. Insonification accelerates clotbreak down in combination with rt-PA and ultra sound contrast agents, which nucleate sustained bubble activity, or stable cavitation. Mechanisms for ultrasound enhancement of thrombolysis and sonobactricide, with a special emphasis on acoustic
cavitation and radiation force, will be reviewed.
Lecture Learning Objectives
At the end of this lecture, participants should be able to:
1. Describe the potential for ultrasound-mediated, image-guided, drug delivery
2. Discuss the mechanisms of ultrasound accelerated rt-pA thrombolysis
3. Describe the pathology of bacterial loaded biofilm responsible for vegetative endocarditis.