An interesting bit of research out of Ohio State University that seeks to solve one of the most intractable problems in modern medicine. Needles. Nobody likes them, but they’re an essential part of what healthcare practitioners do.
It’s amazing how big an impact getting stuck by a needle can have. If you work in the field, you’ve no doubt seen this firsthand. An otherwise tough as nails patient cringes, winces, hisses, mutters profanity, and is sometimes reduced to tears the moment you stick him (or her) with a needle.
The development of a pain free needle would be a game changer in the medical world, but how on earth would one go about it? Researchers at Ohio State think the answer lies in studying the humble mosquito.
After all, when a mosquito bites you, what it’s actually doing is inserting a needle-like probe into your skin so he can feed. Often, he’ll feed on you for several minutes before you’re even aware of it, so there’s certainly something to the idea.
Bharat Bhushan, a Professor of Mechanical Engineering at Ohio State, and member of the research team summed it up this way:
“Mosquitoes must be doing something right if they can pierce our skin and draw blood without causing pain. We can use what we have learned from mosquitoes as a starting point to create a better microneedle…right now, needles are very simple. There hasn’t been much innovation and we think there’s a way to try something different.”
Bhushan has built his career around studying nature and using his findings to improve products, so in that respect, his focus on mosquitoes comes as no surprise. The research was interesting, mostly involving diving deep into previous studies conducted by entomologists, but the team had a very specific focus.
Using their extensive backgrounds in engineering, they broke down the biomechanical parts of the mosquito that contributed to painless mosquito bites.
One of their key areas of focus was the outer covering of the mosquitoes proboscis, called the labrum. Their goal was to measure how hard and stiff it was in several places so they could use it as a guide for potentially creating needles based on the same design. Of interest, they discovered that the labrum was softest near its tip and edges, becoming harder and stiffer farther up (and in) the labrum.
Another discovery of interest was the fact that the part of the proboscis responsible for the intake of blood (called the fascicle) actually more closely resembles a saw than a needle. While that sounds like it should be more painful, not less, in reality the serrated edges make insertion easier, especially given that the mosquito vibrates it as it’s being inserted, which helps to reduce the force needed to pierce the skin.
Finally, another critical factor to pain free mosquito bites involves their use of a numbing agent. When they bite, they release saliva into the wound. Mosquito saliva contains a protein that lessens pain. Put those elements together and you get a pain free “needle.”
Translating that into an artificial needle, Bhushan envisions a microneedle that contains two even smaller needles inside. One would “hit first,” and immediately inject a numbing agent. The second needle would have a serrated design and be softer at the tip and edges. Like the mosquito’s fascicle, it would vibrate as it’s being inserted.
Obviously, such a needle would be more expensive than the needles in use today, but patients would almost certainly be willing to pay a premium for a pain free experience.
Bhushan summarizes: “We have the materials and knowledge to create a microneedle like this. The next step is to find the funding support to create and test such a device.”
The sooner that happens, the better.