Momentum - The Magazine for Virginia Tech Mechanical Engineering Vol. 2 No. 4 Winter 2017 | Page 23

releases the loaded drug particles.
Focused ultrasound waves are those with fre-
quencies higher than the upper audible limit of
human hearing. The use of this unusual trigger
to activate the shape-memory polymers is what
sets the team’s findings apart from others doing
similar work in the field of drug delivery systems.
The benefits of using focused ultrasound
waves to activate the shape-memory polymer
drug delivery container, instead of light or heat,
include the flexible, noninvasive nature of the
stimulus. Previous shape-memory polymer
containers have relied on natural body heat for
activation and can be difficult to control. Other
noninvasive methods, such as magnetic fields
or exposure to light, require special particles to
generate a response. These additional particles
can compromise the biodegradability and
biocompatibility of shape-memory polymers.
Shima Shahab, an assistant professor in the
Department of Biomedical Engineering and
Mechanics and Bhargava’s faculty advisor, co-au-
thored the study alongside Reza Mirzaeifar, an
assistant professor of mechanical engineering;
Jerry Stieg, a mechanical engineering undergrad-
uate; and Kaiyuan Peng, a Ph.D. student in the
mechanical engineering program, all of Virginia
Tech.
to design various ultrasound-activated drug
delivery containers,” said Shahab. “The frame-
works in this study can be specifically tailored for
different applications depending on the size of
drug particles, target time for releasing the parti-
cles, and the size and shape of the container.”
In addition to garnering attention in the field
of drug delivery systems, the findings recently
won the award for Best Student Paper at the
2017 Conference on Smart Materials, Adaptive
Structures, and Intelligent Systems in Snowbird,
Utah.
Shahab and Mirzaeifar first designed the orig-
inal project in a collaboration between Virginia
Tech’s MInDS and MultiSMArt labs in August
2016. While the team’s methods are still years
away from clinical testing in humans, they have
established an important foundation for future
research.
“The study’s outcome moves us one step
closer to the introduction of an efficient new
generation of drug delivery systems,” said
Mirzaeifar. “Our research will continue to focus
on this goal.”
Shahab explained the study’s findings would
pave the way for designing more-efficient drug
delivery capsules in the future, especially those
that can be activated by focused ultrasound
waves.
“We developed an important experimen-
tal-computational framework that can be used
Far left: Assistant
Professor Reza
Mirzaeifar; left above,
Kaiyuan Peng, an ME
doctoral student; left
below, Jerry Stieg an
ME undergraduate
student.
MOMENTUM
WINTER'17

PAGE 23