Quantification of Cell Death due to Ultrasound Therapy
with Contrast Agents
James Dierkes
Advisor: Steven Wrenn
Abstract:
In this work, in vitro studies of the effects of ultrasound therapy with contrast
agents were conducted. Both microbubbles with a phospholipid shell alone and
microbubbles encapsulated with a polymer capsule were utilized as contrast
agents. With increased concentrations of microbubbles, more cell death occurred
due to the increased number of acoustic shock waves. These acoustic shock
waves occur when the acoustic pressure is above the inertial cavitation threshold
of the contrast agent. When the one micron microbubbles are enclosed in a 3-5
micron polymer capsule, no cell death occurred at any pressure or concentration.
This increased cell viability is the result of an increase in the inertial cavitation
threshold due to the coencapsulation of the microbubbles. The coencapsulated
microbubbles proved safer than commercial contrast agents for imaging without
sacrificing the quality of the image.