Medical Design Briefs - January 2025 - 14

Biosensors and Wearables
MDB: How are aptamer-based biosensors
enabling real time diagnostic and
therapeutic drug monitoring?
Rob Batchelor: On the backside of
our coin-size patch are the microneedles.
And so, the microneedles are just
barely going into the skin, about half a
millimeter into the skin. And then code
it on the outside of these microneedles.
The microneedles are also electrodes
and on the outside of these microneedles
are the aptamers. Those
aptamers are sort of the DNA version
of antibodies, and just like antibodies,
they give specificity. This allows
us to get specificity for a particular
drug, say, vancomycin, and then the
way that this happens is you have
one end of the aptamer. An aptamer
is a single stranded bit of DNA, so
one end of the DNA is attached to
the electrode on the microneedle
surface. The other end has a redox
tag, and this redox tag is a certain
distance away from the surface of
the electrode so you can interrogate
that electrochemically in the absence
of the target, say vancomycin,
and you get a certain amount of current.
Then, in the presence the vancomycin,
you get the change and
the distance of that redox tag either
moves further away - or more likely
- it moves closer to the electrode,
and you get an increase of current.
This increase in current can be measured
using electrochemistry, and we
can say we've got a certain amount of
amps. Now we've got more amps for
micro amps as it were, and then we can
convert that into a drug concentration.
So that way we can see the rise and fall
of the vancomycin as it goes up and
down. And so, the physician changes
the drug concentration in the body.
This is binding a molecular physical
change into an electrical current,
which then we can measure and then
put on an output to like a wireless device.
That's the real power of this.
MDB: What are the potential applications
going forward for these DNA-based
sensors?
RB: Therapeutic drug monitoring is
the first application. Relatively dangerous
antibiotics can really affect the patient's
kidneys or other parts of the
14
body. Clinicians are really excited
about being able to measure those in
real time, but that's the just sort of the
first cohort. Then other metabolites
such as creatinine or lactates, or potentially
glucose, would allow you to measure
those very interesting, clinical,
clinically interesting metabolites in
time. That way you can see the rise and
fall, and so you're not just getting a
snapshot, say, every five or six hours or
however often you take a blood draw
or urine sample. You can see these every
few minutes.
the chemical reactivity that's required.
Now there are many other technologies
that allow you to do sort of the
point of care. Lateral flow assays are
great technology if you're looking for a
binary answer. But for drugs - in particular
- from metabolites, it's very
interesting to see the rise and fall of
those over time. Snow you're talking
about nerve cells talking to each other
on a subsecond time scale that would
be really powerful, and then you can
see how those modulate by different
drugs or by performance. It allows you
to personalize it.
MDB: How are DNA-based or
aptamer- based sensors going to
transform the
diagnostics
landscape
and the future?
RB: It is really about two things.
Instead of a single data point, Nutromics' patch tracks multiple, crucial
targets continuously and in real time, giving clinicians critical,
personalized insights. (Credit: Nutromics)
And then you can also start to think
about the back of the patch before you
get sort of the bed-of-nails effect. You
can put dozens of different electrodes
on there. With different microneedles,
you can start to think about measuring
dozens of different biomarkers or drugs
over time. Now the first in the first case,
we're interested in just looking every 24
hours, but you can imagine if we can get
to the length of time that the continuous
glucose monitors have, say, you know two
weeks or even three weeks, so then you
can see the rise and fall of dozens of analytes
going up and down for two or
three weeks.
MDB: How is the Nutromics patch different
from other existing technologies?
RB: It really is that by having this
real- time continuous data, it allows you
to find sort of the rise and falls. Current
technology is at best maybe every
30 minutes every 60 minutes. The nice
thing is that you're moving away from
www.medicaldesignbriefs.com
One, it's giving people more information,
and that's both the clinicians
and then also the patient
themselves. And top of that, it's
giving them better information. As
opposed to getting a once every
few hours or once every day, it's
going to allow you to see what's
going on. A really good case in
point that is for people that have
organ transplants.
The current state-of-the-art is
that they go in, every few months and
they get a blood draw to monitor
whether they have been taking their
immunosuppressants, but who knows
what's going on for those other few
months? It's having better data and
then that is going to allow people to
make the choices that they want for
the lifestyle they want. And it is moving
from the reactive medicine to proactive
medicine. We've already looked
at a handful of those particular biomarkers.
I'm sure there are dozens if
not hundreds, of other biomarkers
that would be very interesting to see
and that would give us better predictive
ability better health performance
characteristics.
To listen to the entire podcast, go to
https://ow.ly/q5ZJ50UsPFt. Listen to
more MDB podcasts at https://www.medicaldesignbriefs.com/mdb/webcasts/podcasts,
or on Spotify or Apple podcasts.
To learn more about Nutromics, visit
www.nutromics.com.
Medical Design Briefs, January 2025
https://ow.ly/q5ZJ50UsPFt https://www.medicaldesignbriefs.com/mdb/webcasts/podcasts https://www.medicaldesignbriefs.com/mdb/webcasts/podcasts https://www.medicaldesignbriefs.com/mdb/webcasts/podcasts http://www.nutromics.com http://www.medicaldesignbriefs.com
Medical Design Briefs - January 2025

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