Medical Design Briefs - December 2021 - 22

The coating allows for certain
liquids to move across surfaces
without fluid loss. (Credit:
University of Toronto)
Nature-Inspired Coatings
Could Power Tiny Labs
A newly developed coating that
allows for certain liquids to move
across surfaces without fluid loss
could usher in new advances in
medical testing. The new coating
was inspired by the natural world.
The innovation has important
implications for microfluidics.
The new coating enables low surface
tension liquids to be transported over distances of over
150 mm without losing any of the liquid, about 15 times longer
than currently possible.
The technology uses two newly developed polymer coatings,
one of which is more liquid repellent than the other. Both are
composed of liquid-like polymer brushes. The more repellent
coating acts as a background, surrounding the less repellent
coating and creating tiny channels along the surface. The
channels allow for the liquids to move in a desired pattern or
direction without losing any of the liquid during transport or
requiring additional energy input.
The ability to transport low surface tension liquids without
loss will allow for advancements in lab-on-a-chip devices.
For more information, visit www.medicaldesignbriefs.com/
roundup/1221/coatings.
A diagnostic nanoparticle can reveal
the presence of cancerous proteins.
(Credit: MIT)
Noninvasive Test
Detects Cancer Cells
A new diagnostic nanoparticle
can reveal the presence
of cancerous proteins
through a urine test, and it
functions as an imaging
agent, pinpointing the
tumor location. In principle,
this diagnostic could
be used to detect cancer
anywhere in the body, including tumors that have metastasized
from their original locations.
The researchers showed that the diagnostic could be used
to monitor the progression of colon cancer, including the
spread of metastatic tumors to the lung and the liver.
Eventually, they hope it could be developed into a routine
cancer test that could be performed annually.
The researchers wanted to develop what they call a multimodal
diagnostic, which can perform both molecular screening
(detecting the urinary signal) and imaging, to tell them exactly
where the original tumor and any metastases are located.
To modify the particles so they could also be used for PET
imaging, they added a radioactive tracer called copper-64.
They also coated them with a peptide that is attracted to
acidic environments, such as the microenvironment in
tumors, to induce the particles to accumulate at tumor sites.
Once they reach a tumor, these peptides insert themselves
into cell membranes, creating a strong imaging signal above
background noise.
For more information, visit www.medicaldesignbriefs.com/
roundup/1221/cancer.
22
Cov
Wearable Sensors Measure
A sensory glove uses
flexible polymers and
carbon fiber. (Credit:
University of Groningen)
Body Position
Scientists have created wearable, stitchable,
and sensitive sensors from flexible
polymers and bundles of carbon fiber.
The sensors respond to pressure and can
measure body position and movement.
They could be used to measure disease
progress in Parkinson's disease, or sense
joint movement in athletes, for example.
The researchers used electrospun carbon
fibers for the sensors. The fibers are
piezoresistive, which means that their
conductivity changes when they are stretched. Sensors are
made by embedding the fibers in a flexible elastomer in a perpendicular
pattern, creating pixels where two fibers cross. The
material can be stitched, whereby it is possible to use conductive
yarn that can act as an electrode. The sensors can therefore
be integrated into everyday clothing or gloves or applied
as patches on joints. They can measure bending movements,
but they are also sensitive to pressure.
The researchers are testing the sensors in a rehabilitation
centre for Parkinson's disease patients. The sensors are being
used to monitor the deterioration of patients' gait over time .
For more information, visit www.medicaldesignbriefs.com/
roundup/1221/sensors.
Optical Cochlear
Implants Offer Better
Hearing
Left: 3D microscopic image of an optical
LED-based cochlear implant. Right:
optical cochlear implant in the basal
turn of the marmoset cochlea. (Credit:
Daniel Keppeler, UMG)
The development of
optical cochlear implants
is complex. One factor is
the complicated structure
of the cochlea, which is
poorly accessible for investigation,
even by imaging
because it is deeply em -
bedded in the temporal bone. However, detailed knowledge of
the structure of the cochlea is critical for the development of
innovative therapy of deafness. Researchers rely on animal
studies to develop the gene therapy and optical cochlear
implants and to test their efficacy and safety.
With the data obtained on the anatomy of the different
cochleae, a team was able to design an implant with LED emitters
for common marmosets. The implant was then inserted by an
experienced ear, nose and throat surgeon in a manner analogous
to surgery in humans. The researchers used imaging data to simulate
the propagation of light generated by the emitters of the
optical implants in the cochlea of nonhuman primates.
The simulations indicate spatially limited optogenetic excitation
of auditory neurons and thus higher frequency selectivity
than with previous electrical stimulation. According to these
calculations, optical cochlear implants lead to significantly
improved hearing of speech as well as of music. Optical stimulation
would lead to a much more differentiated auditory
impression than the electrical stimulation used so far.
For more information, visit www.medicaldesignbriefs.com/
roundup/1221/cochlear.
www.medicaldesignbriefs.com
ToC
Medical Design Briefs, December 2021
http://www.medicaldesignbriefs.com/roundup/1221/coatings http://www.medicaldesignbriefs.com/roundup/1221/sensors http://www.medicaldesignbriefs.com/roundup/1221/cochlear http://www.medicaldesignbriefs.com/roundup/1221/cancer http://www.medicaldesignbriefs.com
Medical Design Briefs - December 2021

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