Medical Design Briefs - April 2022 - 43

Tiny thermometer directly monitors
changes in temperature when
ions pass through a nanopore.
(Credit: Osaka University)
Tiny Thermometer Measures
Temperature in Nanopores
Nanopores, which are tiny openings
in a membrane so small that
only a single DNA strand or virus
particle can pass through, are an
exciting new platform for building
sensors. A direct measurement of
the thermal effects caused by these
ions can help make nanopores more practical as sensors.
A team of researchers has created a thermocouple made of
gold and platinum nanowires with a point of contact just 100
nm in size that served as the thermometer. It was used to measure
the temperature directly next to a nanopore cut into a 40nm-thick
film suspended on a silicon wafer.
Joule heating occurs when electrical energy is converted into
heat by the resistance in a wire. When studying a 300-nm-sized
nanopore, the researchers recorded the ionic current of a
phosphate buffered saline as a function of applied voltage.
They demonstrated nearly ohmic behavior over a wide range
of experimental conditions.
With smaller nanopores, the heating effect became more
pronounced, because less fluid from the cooler side could pass
through to equalize the temperature. As a result, the heating
could cause a non-negligible effect, with nanopores experiencing
a temperature increase of a few degrees under standard
operating conditions.
For more information, visit www.medicaldesignbriefs.com/
roundup/0422/nanopores.
Available on Demand!
Webinar
Elevate Medical Design: Smart, Cost-effective
TPU Films with Polypropylene Carrier
Platilon® TPU films are widely used as a high-quality material for advanced wound care and
medical wearables. Polypropylene carrier technology has allowed the development of a material that offers a clean, rigid, customizable
solution to converting challenges.
This 30-minute Webinar examines how the alliance of a polypropylene (PP) carrier with thermoplastic polyurethane (TPU) blown films
meets today's high demands in terms of process efficiency and end use performance.
Speakers:
Celeste Dunn
Medical Segment Manager,
Covestro
Jeff Motley
Medical OEM Manager,
Covestro
Coating DNA nanostruc -
tures and then chemically
cross-linking increases resis -
tance to degradation by
DNA nuclease enzymes.
(Credit: Frances Anastas -
sacos Wyss Institute at
Harvard University)
DNA Nanotechnology Tools
Help Develop New Therapies
A suite of diverse, multifunctional
DNA nanotechnological tools offers
unique capabilities and the potential
for a broad range of clinical and
biomedical research areas. DNA
nanostructures have potential to be
widely used to transport and present
a variety of biologically active molecules
such as drugs and immuneenhancing
antigens and adjuvants to
target cells and tissues in the human body.
In two simple cost-effective steps, the approach first uses a
small-molecule, unobtrusive neutralizing agent, PEG-oligolysine,
that carries multiple positive charges, to cover DNA origami
structures. In contrast to commonly used Mg2+ ions that
each neutralize only two negative changes in DNA structures,
PEG-oligolysine covers multiple negative charges at one, thus
forming a stable electrostatic net, which increases the stability of
DNA nanostructures about 400-fold.
Then, by applying a chemical cross-linking reagent known as
glutaraldehyde, additional stabilizing bonds are introduced into
the electrostatic net, which increases the stability of DNA
nanostructures by another 250-fold, extending their half-life
into a range that is compatible with a broad range of clinical
applications.
For more information, visit www.medicaldesignbriefs.com/
roundup/0422/DNA.
Please visit www.techbriefs.com/webinar253
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Medical Design Briefs - April 2022

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