Tech Briefs Magazine - April 2021 - 38

Materials & Coatings
helix of fibers that wrap around one
another like a three-stranded rope. The
strands are not flexible - they're stiff like
pencils and they pack together tightly in a
crystalline array.
A collagen sheet is one large, twodimensional crystal but because of the way
the peptides pack, it is like a bundle of
pencils with half the pencils having the

2.5 μm

leads pointing up and the other half having the eraser end pointing up. The scientists sought to refine the collagen sheets so
that each side would be limited to one
functionality - one surface of the sheet
would be all lead points and the other surface would be all erasers. The ultimate
goal was to develop collagen sheets that
could be integrated with a medical device

250 nm

Electron micrographs give a detailed view of the new nanomaterial. Arrows indicate layers that
form in the tubes, leading the researchers to hypothesize that the sheets form tubes by scrolling
in at the corners.

by making one surface compatible with
the device and the other surface compatible with functional proteins in the body.
When the researchers engineered the
separate types of surfaces into single collagen sheets, however, it caused the sheets to
curl up like scrolls. They then found that
the shape-shifting transition was reversible
- they could control whether a sheet was
flat or scrolled simply by changing the pH
of the solution it was in. They also demonstrated that they could tune the sheets to
shape-shift at particular pH levels in a way
that could be controlled at the molecular
level through design.
The condition around which the transition occurs is a physiological condition
that opens up the potential to find a way to
load a therapeutic into a collagen tube
under controlled, laboratory conditions.
The collagen tube could then be tuned to
unfurl and release the drug molecules it
contains after it enters the pH environment of a human cell.
For more information, contact Carol Clark
at carol.clark@emory.edu; 404-727-0501.

Certain Materials Combined with UV Light Kill Coronavirus
A combination of polymers and oligomers, when combined with UV light, almost completely
kills the coronavirus.
University of New Mexico, Albuquerque

s the deadly COVID-19 pandemic
continues to wreak havoc around the
world, new ways in which to stop the
spread or mitigate the effects of the disease are few.
A research team has discovered the
ability of a combination of certain polymers and oligomers, when combined
with UV light, to almost completely kill
the coronavirus. Although disinfectants
such as bleach or alcohol are effective
against the virus, they are volatile and corrosive, which limit lasting sterilization of
surfaces treated by these products. What
is different about these polymer and
oligomer materials is that when activated
with UV light, they provide a coating that
is shown to be fast-acting and highly effective, reducing the concentration of the
virus by five orders of magnitude.
These materials have shown to have
broad-spectrum antiviral properties. In
order for the material to be active
against the virus, it must be exposed to
light. Light activates the " docking "
process that is important and necessary
for placing the oligomer or polymer at

The researchers are using polymer and oligomer materials to kill microbes on surfaces. (Credit:
UNM Newsroom)

the surface of the virus particle, allowing
the absorption of light that generates
the reactive oxygen intermediate at the
surface of the virus particle.
The materials are not active against
SARS-CoV-2 in the dark and require activation by irradiation with ultraviolet or
visible light, depending on where the specific antimicrobial absorbs light. In the
dark, the antimicrobial materials dock

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with the virus and then on irradiation,
they activate oxygen. It is this active, excited state of oxygen that starts the chain of
reactions that inactivate the virus.
This science can easily be applied into
consumer, commercial, and healthcare
products such as wipes, sprays, clothing,
paint, personal protective equipment
(PPE) for healthcare workers, and almost
any surface. When incorporated into N95
Tech Briefs, April 2021

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Tech Briefs Magazine - April 2021

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