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

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

To avoid needles’ risks and challenges, Traverso and colleagues designed a microjet device that uses pressure to push drugs such as insulin into a variety of organs. Much like the contractions that squids use to pressurize and propel liquid through their funnel-like siphons, this device can precisely direct liquid in different directions depending on the specific target, the team reports November 20 in Nature.

Getting close enough to vital organs requires the microjet to be attached to either a tethered or free-floating device inside of a capsule that travels through the gastrointestinal tract. Other teams have been developing ingestible devices to deliver drugs in the body, but many of them still rely on needles (SN: 2/7/19). Combining these tiny robotics with microjets offers a safer alternative.

“One of the most challenging aspects was optimizing the balance between jet force and safety,” Traverso says. The team used a capsule around the microjet that dissolves at a certain 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 pressure of the jet — depending on the delicacy and thickness of the tissue — and letting gravity do the rest. When testing the device on pigs and dogs, the team found no safety issues.

“This is the first study demonstrating the use of microjets for delivery of drugs into the gastrointestinal tract,” says Samir Mitragotri, a drug delivery researcher at Harvard University who was not involved in the research. “All in all, this is a very creative design.”

While these microjets show promise, they have a long way to go before getting into humans. Future studies will probably investigate how these devices could target specific types of tissues, such as tumors or fibroses. Researchers will also need to ensure that repeated microjet injections to the same site cause no safety problems.

Until then, the needle-fearing among us will need to continue our deep-breathing and distraction techniques when we go to the doctor.