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Billions of years of evolution has resulted in organisms with
oodles of clever and super-efficient adaptations,
many of which are better than anything we’ve ever been able to engineer.
Fortunately, we’re not above, you know,
borrowing from nature to do the important work of saving human lives.
And few fields have benefited more from ripping off the animal kingdom than surgery.
So, if you ever find yourself recovering from a trip to the operating room,
you might have one of these six nature-inspired surgical breakthroughs to thank.
Let’s start with a common category of procedures:
getting something inside of you out.
See, surgeons often need to remove small bits of the human body.
This could be for a biopsy, which is a tissue sample taken for testing, or because
there’s something in there that doesn’t belong, like diseased tissue or a blood clot.
To do this, they use a device called a tissue extractor.
Current tissue extractors rely on suction, but that’s not super efficient.
They’re prone to getting clogged, and the technology limits how small they can be.
Suction-based devices also don’t do a very good job
of pulling tissue through long tubes.
That means they can’t be used to remove tissue in the most well-buried parts
of the human body, such as tumors deep inside the brain.
They’re also not especially gentle.
A suction-based tissue extractor may harm surrounding tissue,
especially if it accidentally sucks up something it isn’t supposed to.
So, to try and improve on this, engineers are working on a new kind of extractor
based on the egg-laying organ of a parasitic wasp.
That organ is kind of like the bit of tube
that goes into your vein when you’re receiving an IV.
Called an ovipositor, this tiny egg-laying structure is thin, hollow and flexible.
But what’s really clever about it is that it’s lined with tiny blade-like structures
that interlock like a three-dimensional puzzle.
The blades move independently,
but work together to guide each egg to its destination.
And now, scientists have created a prototype tissue extractor
inspired by the wasp ovipositor.
The device is described in a 2020 paper,
and it’s a tube made from a bundle of six semi-cylindrical blades.
The blades slide forwards and backwards and, as they move,
they sort of nudge the tissue up the tube.
Researchers hope this device will help reduce trauma during surgery,
allowing surgeons to remove tissue from places that aren’t usually easy to get to.
At the moment, the primary drawback is that the device is anywhere
from 50 to more than 150 times slower than a suction device,
so it’s not great for jobs where speed is a major concern.
Still, the team that developed the device does think they can speed it up
by redesigning the inside of the tube or tweaking the motor’s design,
so there’s still work to be done.
Mosquitoes carry diseases, and they’re also just plain annoying.
But they do have some redeeming qualities—even for medicine.
The proboscis of a mosquito is serrated and super-sharp,
so when she sticks you with it, there’s less contact with your tissue and less overall
force than there is when you get stuck by, say, a nurse giving you a flu shot.
That’s why you can’t even always feel when a mosquito bites you: it only becomes
obvious after she’s taken what she wants and is trying to make a clean getaway.
Meanwhile, some injections can be painful, so it would be great if we could find a
similarly painless way to deliver medication or take a blood sample.
The key seems to be reducing the amount of resistance
as the needle penetrates tissue.
So, using the mosquito proboscis as inspiration, scientists created
a three-part needle and published their progress in another 2020 study.
The two outer needles are based on maxillae—
the needles that mosquitoes use to pierce flesh.
And these needles have been etched by a machine to make them jagged.
Meanwhile, the center needle is straight.
It’s based on the labrum, which is the mosquito mouthpart
that penetrates blood vessels.
The needles move independently but cooperatively,
the way a mosquito's proboscis does.
And tests conducted during this study found that the independent motion
of the three needles, combined with the jagged notches,
were effective in reducing tissue displacement in the test material.
That means it should also reduce pain in real life.
It’s not clear when we’ll see this tech roll out into the real world,
but I am looking forward to that day!
Animals aren’t the only species in nature that inspire us.
We can also learn something from plants, too.
Like, when a cucumber tendril touches something,
tactile sensors on the tendril induce it to coil,
which anchors the plant securely to whatever object the tendril has encountered.
And doctors sometimes use tendril-like devices, too.
Called robotic manipulators, these devices allow a surgeon
to operate on an internal body part without the need to create a large, invasive cut.
The problem with these surgical devices is that they’re not super flexible,
and it can be hard to steer them around sensitive organs and tissues.
So in 2014, researchers decided to try to improve on current designs
with cucumber-inspired tech.
The idea is to add a bunch of tiny sensing devices
to the surface of the robotic manipulator.
When these sensors encounter something, like a bone or organ,
they can measure the amount of pressure.
Then, they can use that info to make automatic adjustments
or just provide feedback so the surgeon can decide what to do next.
A robotic manipulator with sensors like this could make minimally-invasive surgery
even less risky. It would minimize the risk of injuring tissue during a collision
or accidentally severing something that isn’t supposed to be cut.
All thanks to cucumbers.
Next, one of the holy grails of surgery is a glue
that can keep stuff stuck together in our warm, wet, squishy insides.
Which sounds kind of similar to the underwater environments
inhabited by some marine and freshwater mussels.
To stop themselves from drifting away,
these creatures make unique structures called byssal threads,
which keep them securely anchored to rocks and other surfaces.
To make the threads, a mussel’s byssal gland secretes
a collection of proteins that form sticky tethers.
The really cool thing about byssal threads is that the mussel can remain attached to
rocks, other mussels, boat bottoms, or whatever,
even underwater and in the presence of strong surf.
And researchers are especially interested
in developing a glue like that for fetal surgery.
Surgery in the womb is very tricky because
if the incision breaks open afterwards, the results can be tragic.
If amniotic fluid leaks through a ruptured incision,
it can lead to early labor and premature birth.
So, during fetal surgery, a mussel-inspired glue
could pre-seal the fetal membrane before an incision is made.
Surgeons would use it to make a sort of patch between the uterine wall and the
fetal membrane, before making the incision through that patch.
That would create a watertight seal around the surgical instruments,
and help stabilize the incision during surgery.
Researchers began developing this glue in 2010,
and it’s based on something called DOPA,
an amino acid residue found in the mussel’s foot proteins.
It’s still a work in progress, though—designers are continuing to perfect the formula
with other mussel-inspired sticky substances.
But so far, it’s a really clever idea.
Like, who would have thought I’d say “mussel-inspired glue” and “fetal surgery”
in the same sentence?
Pomphorhynchus laevis is a parasitic worm that preys on fish.
It has a head that looks kind of like a barrel cactus,
and it uses these spines to anchor itself to the tissue of its host.
Then, its head gets bigger until it becomes sort of plug-like. Which sounds
just horrible for the fish, but guarantees a secure attachment for the worm.
And researchers are hoping they can copy this trick to make skin grafts less horrible.
Skin grafts are notoriously painful and can go wrong in a lot of ways.
Staples and stitches hurt, can damage tissue, they’re prone to infection...
And stapling around the edges isn't always super effective because,
if the graft doesn't stay flush with the tissue it's covering,
then fluid can fill in the space underneath it and cause the graft to fail.
So, scientists were inspired by Pomphorhynchus’ mode of attachment
when they designed this new skin graft technology in 2013.
Researchers added tiny cone-shaped needles to the surface of the graft,
each one less than half a millimeter wide at the base.
Their small size helps them penetrate tissue gently,
as opposed to the way that larger staples make quick, violent punctures.
And when they contact water, the needles swell.
That locks them securely into place, just like the worm’s head does.
Since there are a lot of them, the graft usually stays flush,
which further reduces the risk of complications.
They’re a lot easier and less painful to remove than staples, too,
since the swelling process is totally reversible.
So—and it feels weird to say this—thanks, worm parasite!
Finally, contrary to popular belief, geckos don't have anything sticky on their feet,
and they don't have little suction cups on their toes, either.
And, yet, geckos can be found attached securely to almost any surface.
Which would be a great attribute for a bandage.
What gecko feet do have is a series of tiny structures called spatulae.
The spatulae are arranged on each of the millions of tiny hairs, called setae,
that cover the bottoms of the gecko’s feet.
There’s nothing chemical happening with the spatulae and the setae—
it’s all about geometry.
When the gecko puts its foot down, the setae and spatulae come into very close
contact with the contours of whatever surface the gecko is climbing.
This creates a kind of electrostatic connection between the molecules of the
foot hairs and the molecules of the surface material.
The result: sticky feet. Minus the glue.
Bandages that could do something similar would be pretty useful.
Surgeons could use them to wrap up wet surfaces like those inside a human body.
Imagine wrapping an intestine the way you might bandage a finger.
To make a bandage that could do this, you need a material that sticks
but is also biodegradable, flexible, and doesn’t cause inflammation.
So in 2008, designers used a rubber-like substance to create a bandage
with the texture of a gecko’s foot, and made just a little bit stronger
with a layer of sugar-based glue.
These bandages can be folded, which means they can be inserted through
very small incisions made during minimally-invasive procedures.
And because it’s biodegradable, the bandage doesn’t have to be removed.
That makes it ideal for things like gastrointestinal surgery,
or repairing ulcer damage in the stomach.
Overall, humans are pretty clever inventors, so it’s kind of humbling to think that
nature was able to devise solutions to so many of our problems
before we even knew what those problems were.
Also, it’s a reminder that basic research—
like how parasitic wasps deposit their eggs—
can sometimes have huge, totally unexpected payoffs.
Speaking of pokey, stabby things like ovipositors…
There are only a few days left to get our pin of the month!
Every month, we release a new pin inspired by an amazing space mission,
and this month, it’s SOHO: the Solar and Heliospheric Observatory!
If you want to learn about the mission,
you can head over to SciShow Space after this.
And if you want the pin, you’ll only be able to get it until the end of December!
So you can find it at DFTBA.com/SciShow.
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