Canberra researchers studying bee stingers may help develop the next generation of micromedical devices

Key points:

• UNSW Canberra researchers have made a 3D render of a bee stinger which could inspire micro medical devices
• The team believes recreating the unique geometries could help keep devices and patches in place
• Researcher Dr Fiorella Ramirez Esquivel says recreating the stinger’s barb is possible, but the tiny pistons will take longer yet

Bio-engineer and Associate Professor Sridhar Ravi was inspecting a colleague’s backyard beehives when research inspiration for medical tools struck — or, more accurately, stung.

“One of the bees stung me near my eye,” he said.

“It was a very painful experience, but it got me thinking about the stinger. Why is it so painful? How is it so effective?”

In an effort to find answers Dr Ravi and his team at the University of New South Wales (UNSW)’s Canberra campus produced high-resolution imagery of the honey bee’s stinger, which they believe could help develop the next generation of minimally-invasive medical tools and treatments.

“There’s been lots of imagery done with bee stingers, but only really certain parts of it,” he said.

“This is the first time that different techniques are being applied together, for us to build this comprehensive 3D rendering of the whole thing.”

High-speed cameras, light microscopy, micro-CT and SEM imagery helped unlock the secrets of the worker bee’s 2mm-long defence mechanism, revealing two harpoon-like lancets, each with around 10 backwards-facing barbs.

Similar to pistons, the lancets take it in turns to stab and retract over a bevel-tipped stylet, piercing and then digging into the skin and staying put, without buckling or breaking.

And, even separated from the bee, the stinger can function autonomously to continue pumping venom.

Another member of the UNSW Canberra team, Dr Fiorella Ramirez Esquivel, said the renderings allow researchers to observe a bee’s stinger in action.

“We can measure the angle of the barbs and how big they are, which means that we can replicate it fairly accurately,” she said.

“We feel like we’ve compiled a bit of an atlas of the bee stinger!”

The UNSW Canberra team believe the stinger’s “unique geometries” lend themselves to redesigned or refined medical anchoring methods, and could help keep devices or patches in place “without the need for chemical adhesives, which can cause [skin] irritation or be unviable on moist surfaces, like the inside of the body.”

“Bio-inspired engineering has been a thing for quite a long time,” said Dr Ramirez Esquivel.

“But how the bee stinger allows for easy insertion and difficult removal; that is really interesting for mechanical, medical adhesion.

“For other applications … maybe, one day, you might see it in an insulin pump or very, very targeted drug delivery.”

Associate Professor Malcolm Boyle, who leads Griffith University’s paramedical education program, also sees the development of “a slow-dose vaccine” as a possibility from the research.

Professor Boyle said the bio-inspired engineering could also be utilised for diabetic insulin pumps and “pain-relief patches [like] fentanyl or glyceryl trinitrate patches”.

But Dr Ramirez Esquivel said man-made manufacturing has to catch up with nature’s design first.

“
The mechanical barb-attachment thing is … a bit easier to produce at the moment, with the technology that we have,” she said.

“[But] generating those tiny, collapsible pistons is going to be some time off, I think!”