Translator: Zeddi Lee Reviewer: Peter van de Ven
The US Navy has always had this frustrating problem with their fleet.
It's something called "fouling."
Now, for all you non-seafaring folk,
fouling is when things like algae and barnacles and other marine materials
get stuck to the sides of ships and submarines.
Used to be able to prevent this fouling
by coating ships and submarines with toxic agents, like heavy metals,
but these heavy metals
aren't as effective at keeping ships clean as they used to be.
And we want clean ships
because fouling on these vessels
actually makes them less efficient in the water
and can be easier for enemies to detect.
This is not good.
So several years ago, the US Office of Naval Research
called on one of my colleagues, engineer scientist Dr. Anthony Brennan,
to devise a solution to prevent fouling
without the use of these heavy metals.
See, Dr. Brennan was already investigating
how things like surface roughness
can prevent the attachment of organisms like algae.
But Dr. Brennan was struggling.
All of the engineered surfaces he came up with
algae eventually overcame.
And then Brennan found himself at a conference in Hawaii, of all places,
and noticed something rather intriguing.
Take a look at these three animals:
a manatee, a whale and a shark.
What do you notice?
Well, right.
So the whale and the manatee are filthy,
but the shark is squeaky clean.
This is a property unique to all sharks.
The next time you watch Shark Week,
you'll notice each and every shark you see
is pristine.
(Laughter)
Why?
Brennan wanted to find out.
So with the help of some brave graduate students,
they set out to find a shark.
(Laughter)
They found one in the shallow water
and carefully took a mold of its skin using a dental impression material.
Don't worry.
The shark wasn't harmed in the process, although I'm sure he didn't appreciate it.
(Laughter)
So the students took the mold back to the lab and put it under a microscope,
and this is what it looks like.
The sharkskin is comprised of little denticles,
and they overlap to create a diamond-shape repeating pattern on the sharkskin.
Upon further investigation,
Brennan and his team noticed that the texture on these denticles
is actually what's responsible for keeping sharks clean.
I'm a microbiologist and infectious disease expert,
and I find this fascinating.
I've spent my career trying to keep surfaces clean,
especially the surfaces of medical devices.
In hospitals this is a massive problem.
See, what happens is bacteria who are really normally good
find themselves in places they shouldn't be
as a result of some medical procedure.
Sometime during or after surgery,
bacteria latch onto the surface of a medical device, stay there,
and cause a serious infection;
and this makes it impossible for the body to heal.
Take a look at these surgical wires
used to close a patient's sternum following open-heart surgery.
Notice the tiny clusters of bacteria on the surface?
This patient didn't heal for months
until the wires were removed, and replaced with clean ones.
You know, it used to be
we just used antibiotics to treat these types of infections.
Antibiotics were an amazing drug,
for a while.
But eventually, bacteria were exposed to antibiotics so frequently
they were forced to adapt.
And survival is the key driver of evolution,
and that's what we're talking about here:
bacterial evolution.
Perhaps you've heard about this in the news.
It's referred to as "Antimicrobial Resistance."
The US Centers for Disease Control and Prevention
call antimicrobial resistance
one of the greatest public health challenges of our time.
Illnesses that were once easily treatable
are now untreatable.
In the US alone every year,
more than two million people will get an antibiotic resistant infection,
and over 23,000 people will die as a result of that infection.
The pharmaceutical industry
is rushing to develop more and more and more antimicrobials,
desperately trying to outpace antimicrobial resistance.
But bacteria and germs,
they evolve so much more quickly than we could innovate ways to kill them.
It's clear the antimicrobial era is coming to an end,
so we have to think about this in a whole new way.
What if instead of trying to kill bacteria after they cause infections,
we simply make it harder for bacteria
to stick to the surfaces of medical devices in the first place?
In other words,
we prevent these infections from occurring altogether.
That's what brings me back to what we've learned from sharks.
It's the texture of sharkskin that makes them resistant to fouling.
So what if we change the texture of medical devices
to make them resistant to bacteria causing so many problems?
Dr. Brennan knew he had a major medical breakthrough on his hands.
He called up some trusted friends right here in Denver Colorado,
and they started a company, and they called it Sharklet Technologies.
In 2013, I joined the team,
and together we used engineered surfaces mimicking the skin of sharks
to prevent bacteria and other medical complications.
Our first commercial device is a urological catheter,
which doctors began using for patients just last year.
(Applause)
Take a look at these example images.
The surface on the left is a smooth surface,
and the one on the right is a sharkskin-like texture.
Notice how much bacteria's on the smooth surface
compared to the sharkskin-like surface?
This is because the sharkskin-like texture
creates an inhospitable surface for bacterial attachment and growth.
It works on sharks, and it works here too
because the texture takes advantage of principles of surface energy.
Now, surface energy
is really a description of a detailed property of a surface.
It can include things like water interaction or material stiffness.
The roughened sharkskin-like texture
creates a surface with greater surface energy.
You know, we interact with surface energy changes all the time.
We often just don't notice it.
For example, we like when rain beads up and runs off our car, right?
Well, this happens best with a nice coat of wax.
Wax is a material with greater surface energy characteristics.
Now, we can't coat medical devices in wax,
but we can change their surface texture.
And this approach works on all types of medical devices,
from catheters to pacemakers,
and it's effective against all types of bacteria and germs.
As it turns out,
we can actually do more than just bacteria-proof medical devices.
We can prevent other medical complications
through understanding the power of surface energy,
things like frequent clogging,
excessive blood clotting
or poor healing interactions.
The next generation of medical device surfaces
inspired by the skin of sharks
will actually expand how medical devices are made.
Really the core issue
is that we create all types of sophisticated medical devices,
things to pump fluid into our blood,
keep our heart beating on pace,
or even stimulate brain activity.
But bad things happen
when these devices don't interact well with our bodies' natural mechanisms.
We've actually discovered
that we can improve how medical devices are tolerated
through subtly tuning the surface energy characteristics,
like for example, we can prevent a lot of the excessive clotting
that's occurring here on the smooth surface,
compared to the sharkskin-like texture.
This means that we can actually match the required surface energy
with the medical use
to prevent complications,
all with the power of sharks.
Ultimately, as we continue to engineer smart surfaces,
we'll require fewer antimicrobials,
fewer chemicals and fewer harsh additives,
and this will make life-saving medical technology
safer for all of us to use.
This is innovation in its purest form, to be sure.
But it's also a good reminder
of just how important it is to observe the subtle cues
in the raw mystery of the world around us.
Thank you.
(Applause)