Medical Design Briefs - September 2023 - 34

n Biodegradable Polymer
for Treating Rheumatoid
Arthritis
Engineers have developed
n Stretchable OLED
Display for Wearables
Researchers have dea
biodegradable polymer
system to treat rheumatoid
arthritis, an autoimmune
and inflammatory disease,
by working in concert with
the power of the human immune
system.
The research builds on increasing clinical interest in modulating
the immune system to treat cancers and autoimmune
disease, as well as previous work with all-trans retinoic acid
(ATRA) which is produced naturally in the body and helps cells
grow and develop. By approaching these challenges from the
perspective of a biomaterials engineering lab, the team adds
two key innovations to previous methods: local release and harnessing
the joint microenvironment for sustained effectiveness.
With this method, encapsulated ATRA is injected directly
into a joint affected by rheumatoid arthritis, where it remains
in effect for at least several weeks. During that time, ATRA
transforms disease-causing cells into disease-stopping cells,
known as regulatory T cells, which can treat or prevent the
disease elsewhere in the body. (Image credit: UC San Diego's
Nano3 facility, Jacobs School of Engineering.)
For more information, visit www.medicaldesignbriefs.com/
roundup/0923/polymer.
n Ingestible Capsule
X-Ray for Real-Time
Monitoring
An ingestible x-ray dosimeter
detects radiation dose in
real time. Combining the novel
capsule design and a neural
network-based regression model
that calculates radiation dose
from the information captured by the capsule, researchers found
that they could provide approximately five times more accurate
monitoring of the dose delivered than current standard methods.
The capsule can measure the dose of radiation and physiological
changes in pH and temperature in real time during gastrointestinal
radiotherapy. Key components of the capsule include
a flexible optical fiber encapsulated with nanoscintillators
that illuminate in the presence of radiation, a pH-responsive
film, a fluidic module with multiple inlets for dynamic gastric
fluid sampling, two sensors for dose and pH measurements, a
microcontroller circuit board that processes photoelectric signals
to be transmitted to a mobile application, and a buttonsized
silver oxide battery powering the capsule.
When the capsule is ingested and reaches the gastrointestinal
tract, the nanoscintillators exhibit heightened luminescence
in the presence of increased x-ray radiation. A sensor
within the capsule measures the glow from the nanoscintillators
to determine the radiation delivered to the targeted area.
The fluidic module allows gastric fluid to be collected for pH
detection. (Image credit: National University of Singapore)
For more information, visit www.medicaldesignbriefs.com/
roundup/0923/capsule.
34
signed a thin, digital display
that can bend in half or
stretch to more than twice
its original length while still
emitting a fluorescent pattern.
The material has a
wide range of applications, from wearable electronics and
health sensors to foldable computer screens.
The team developed atomic models of the new polymers of
interest and, with these models, simulated what happens to
these molecules when you pull on them and try to bend
them. A key feature in their design was the use of " thermally
activated delayed fluorescence, " which let the materials convert
electrical energy into light, in a highly efficient way. This
third-generation mechanism for organic emitters can provide
materials with performance on par with commercial
OLED technologies.
Bendable materials that emit light can be integrated into
wearable sensors that require light such as measuring blood
oxygenation and heart rate. A bendable light-up material also
could be integrated into implantable devices, such as those that
use light to control the activity of neurons in the brain. (Image
credit: Wang Group/University of Chicago)
For more information, visit www.medicaldesignbriefs.com/
roundup/0923/display.
n Wood-Derived ElectronicSkin
Substrates
Researchers have designed
wood-derived electronic-skin substrates
for electrophysiological
monitoring that are functional,
sustainable, and comfortable.
The cellulose-based material is
essentially paper made up of
tiny nanofibers, giving it the
name nanopaper e-skin, and it is
the gaps between the fibers,
whose size can be controlled, that give the substrate its edge.
Because the nanopaper is a mesh of very fine fibers, it
maintains good contact with the skin, but it also has pores,
meaning that water vapor can pass through, reducing inflammation
and making it comfortable to wear. Once wet,
the nanopaper was able to stick to skin because of the action
of the water in the pores and was able to withstand 100
cycles of deformation on the forehead while maintaining
function. The nanopaper could also be sterilized at high
temperature.
The availability, flexibility, thermal stability, biocompatibility,
skin-conformability and -breathability , toughness, and environmental
sustainability of the substrate all combine to make it a
highly promising candidate for electrophysiological monitoring
that the researchers expect to easily translate into the clinic for
the measurement of data such as ECGs. (Image credit:
Osaka University)
For more information, visit www.medicaldesignbriefs.com/
roundup/0923/substrates.
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Medical Design Briefs, September 2023
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Medical Design Briefs - September 2023

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