A medical device inspired by squid could reduce the need for needles

If you’re one of the many adults who hate needles, you may be in luck. Scientists have taken inspiration from squid’s high-pressure liquid jets and developed a needle-free device to inject drugs into organs deep inside the body.

“Needles require specialized training to administer, present challenges with safe disposal and carry the risk of needlestick injuries, whether used externally or for deeper, internal applications,” says Giovanni Traverso, an engineering researcher translational at MIT.

To avoid the dangers and challenges of needles, Traverso and colleagues designed a microjet device that uses pressure to push drugs such as insulin into a variety of organs. Like the contractions that squid use to pressurize and drive fluid through their funnel-like siphons, this device can precisely direct fluid in different directions depending on the specific target, the team reports Nov. 20 in Nature.

To get close enough to vital organs, the microjet is required to be either attached to a tethered device or free-floating inside a capsule that travels through the gastrointestinal tract. Other teams have developed swallowable devices to deliver drugs into the body, but many still rely on needles (SN: 2/7/19). Combining these small robots with microjets offers a safer alternative.

“One of the most challenging aspects was optimizing the balance between aircraft strength and safety,” says Traverso. The team used a capsule around the microjet that dissolves at a specific pH and allows the microjet to precisely target certain parts of the body where the equivalent pH occurs. They successfully injected drugs into the stomach, colon, esophagus and other organs by adjusting the jet’s pressure – depending on the delicacy and thickness of the tissue – and letting gravity do the rest. While testing the device on pigs and dogs, the team found no safety issues.

“This is the first study to demonstrate the use of microbes to deliver drugs to the gastrointestinal tract,” says Samir Mitragotri, a drug delivery researcher at Harvard University who was not involved in the research. “Overall, this is a very creative design.”

While these microjets are promising, they have a long way to go before they make their way into humans. Future studies will probably investigate how these devices can target specific types of tissue, such as tumors or fibroids. Researchers will also need to ensure that repeated injections of the microjet into the same site do not cause safety issues.

Until then, those with a fear of needles will have to continue our deep breathing and distraction techniques when we go to the doctor.