Jongbum Seo

Experiments were conducted to explore the potential of stabilized microbubbles for aiding tissue ablation during ultrasound therapy. Surgically exteriorized canine kidneys were irradiated in situ using single exposures of focused ultrasound. In each experiment, up to eight separate exposures were placed in the left kidney. The right kidney was then similarly exposed, but while an ultrasound contrast agent was continually infused. Kidneys were sectioned and examined for gross observable tissue da

Sonophoresis can increase skin permeability to various drugs in transdermal drug delivery. Cavitation is recognized as the predominant mechanism of sonophoresis. Recently, a new logical approach to enhance the efficiency of transdermal drug delivery was tried. It is to utilize the engineered microbubble and its resonant frequency for increase of cavitation activity. Actively-induced cavitation with low-intensity ultrasound (less than ~1 MPa) causes disordering of the lipid bilayers and the forma

We expect that sonophoresis with specialized URLN in transdermal drug delivery could be used widely for various skin-related applications.

Ultrasound Contrast Agents (UCAs) were developed to maximize reflection contrast so that organs can be seen clearly in ultrasound imaging. UCAs increase the signal to noise ratio (SNR) by linear and non-linear mechanisms and thus help more accurately visualize the internal organs and blood vessels. However, the UCAs on the market are not only expensive, but are also not optimized for use in various therapeutic research applications such as ultrasound-aided drug delivery. The UCAs fabricated in t

Sufficiently high intensity ultrasound can create hyperechoic regions in an ultrasound image due to local bubble generation. We explore the link between the temporal extent of these hyperechoic regions and tissue damage caused by ultrasound therapy. The decay rate of increased echogenicity from the focal zone in insonated live exteriorized canine kidney was quantified and correlated to the spatial extent of tissue damage. The decay half-time, t(half), defined as the time for echogenicity enhance

An anti-focus is defined as the point where the pressure amplitude is zero. As an active protection means in focused ultrasound, the anti-focus was researched through simulations. A 513 element, 1 MHz, 15 cm focal depth, spherical shape transducer with a central hold was used for the simulation. An anti-focus was implemented with two different approaches and the simulation results were compared. First, the interference among foci was compared to the summation of the individual focus fields. Seco

Abstract Ultrasound contrast agents (UCAs), which are groups of engineered microbubbles, have been recently studied for drug delivery applications, since the cavitation of bubbles can increase the temporary permeability of nearby cells. However, the internal volume of UCAs is generally filled with gas, hence loading drug molecules into UCAs is limited. In this study, an echogenic liposome with a liquid and gas core is proposed as an alternative carrier of genetic material for ultrasound‐mediated

A phased-array system appears to have a potential for the non-invasive and region-selective neuromodulation method.

<b>Objective</b>: In previous studies, echogenic liposomes with liquid and gas cores were analyzed as alternative carriers of drug molecules and cavitation nuclei for sonoporation. The possibility of small interfering RNA (si-RNA) encapsulation has also been presented. In this study, the usability of echogenic liposomes as drug carriers and cavitation seeds was evaluated using an in vivo model. <b>Methods</b>: A doxorubicin-loaded echogenic liposome was synthesized as a drug carrier. The size di