Medical Design Briefs - March 2023 - 30

n MicroLED Patch for
The overall concept of SµLED patch. (Credit:
KAIST)
Melanogenesis
A surface-lighting microLED
patch has been
de veloped that inhibits
UV-induced melan o genesis.
The research team
fabricated the skin- attachable
surface-lighting
microLED (SµLED, 4 ×
4 cm2
) patch by utilizing
a thousand micro LED
chips and silica-embedded light dif fusion layer. The 100 µmsized
LED chips are vertically interconnected for high flexibility
and low heat generation, allowing its long-term operation on
the human skin.
The team confirmed melanogenesis inhibition by irradiating
the SµLED patch and the conventional LED (CLED) on the
artificial human skin and mice dorsal skin. The SµLED treated
groups of human cells and mouse tissues showed minimal
epidermal phototoxicity and consistently effective reduction
in synthesized melanin, compared to CLED-treated groups. In
addition, significant suppression of proteins/catalysts expression
involved in melanin synthesis such as microphthalmiaassociated
transcription factor (MITF), Melan-A, and tyrosinase
was verified.
For more information, visit www.medicaldesignbriefs.com/
roundup/0323/patch.
n Sensor Detects Heavy Metals in Sweat
Researchers have developed
a portable sensor
Flexible copper sensor made cheaply from
conductive copper adhesive tape, sheet of
transparency film, paper label, nail varnish,
circuit fabrication solution, and acetone.
(Credit: Anderson 0323 M. de Campos)
made of simple materials
to detect heavy metals in
sweat, which is easily sampled.
The sensor is simple
in terms of the materials
used to make it and the
stages of its production.
The base of the device is
polyethylene terephthalate
(PET), on top of which is a
conductive flexible copper adhesive tape with the sensor printed
on it, and a protective layer of nail varnish or spray. The exposed
copper is removed by immersion in ferric chloride solution for
20 minutes, followed by washing in distilled water to promote the
necessary corrosion.
The device is connected to a potentiostat to determine the
concentration of each metal by measuring differences in potential
and current between electrodes. The result is displayed on a
computer or smartphone using appropriate application software.
The sensor's performance in detecting lead and cadmium was
assessed in trials using artificial sweat enriched under ideal experimental
conditions. Adaptations are required before the device
can be patented.
For more information, visit www.medicaldesignbriefs.com/
roundup/0323/sensor.
30
The circuit board for the biosensor.
(Credit: Minghan Xian, et al.)
Glucose-Based detection
Glucose
SARS-CoV-2
spike RBD
Ant-spike
patient Ab
Sucrose
Ab+Inv
With this reaction, a glucose meter
can detect SARS-CoV-2 antibodies in
patient samples (Ab=antibody; Inv=invertase).
(Credit: Journal of the American
Chemical Society)
n Glucose Meter Monitors
SARS-CoV-2 Antibodies
A simple and accurate
glucose- meter-based test incorporates
a novel fusion protein
could someday be used to monitor
SARS-CoV-2 antibody levels.
Glucose meters are readily
available and easy to use, and
they can be integrated with remote
clinical services. Researchers
have been adapting these
devices to sense other target
molecules, coupling detection
with glucose production.
The researchers designed and produced a novel fusion protein
containing both invertase and a mouse antibody that binds
to human immunoglobulin (IgG) antibodies. They showed that
the fusion protein bound to human IgGs and successfully produced
glucose from sucrose. Next, the team made test strips
with the SARS-CoV-2 spike protein on them. When dipped in
COVID-19 patient samples, the patients' SARS-CoV-2 antibodies
bound to the spike protein.
Adding the invertase/IgG fusion protein, then sucrose, led to
the production of glucose, which could be detected by a glucose
meter. They validated the test by performing the analysis with
glucose meters on a variety of patient samples and found that
the new assay worked as well as four different ELISAs. The researchers
say that the method can also be adapted to test for
SARS-CoV-2 variants and other infectious diseases.
For more information, visit www.medicaldesignbriefs.com/
roundup/0323/antibodies.
n Temporary Tattoos Measure
Blood Pressure
Made of graphene, a cuffless device
is worn on the underside of
the wrist and can measure blood
pressure with comparable accuracy
to a standard blood pressure
cuff. While the technology is still
in its early stages, the researchers
envision that the monitor will be
worn 24/7.
The application involves placing
the device - which is attached to a
thin strip of paper - onto the skin, dampening the paper
with water, and then gently removing the paper, leaving the
blood pressure monitor behind.
The tattoos don't measure blood pressure directly. Instead,
the tattoos rely on bioimpedance - a measure of how the
body resists an electrical current. They contain tiny electrodes
that apply a small current to an artery in the wrist and then
sense how that current is affected by the artery. These bioimpedance
measurements can then be converted into blood
pressure readings using machine learning.
For more information, visit www.medicaldesignbriefs.com/
roundup/0323/tattoo.
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Medical Design Briefs, March 2023
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Medical Design Briefs - March 2023

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