When delivering medications to patients, one of the most effective methods is direct injection （注射） into the bloodstream using a needle. But this can be an uncomfortable experience, especially for kids or adults with a fear of needles. While patients do have the option to take oral pills instead, drugs containing large molecules（分子） are not absorbed effectively this way.
Now, inspired by octopus suckers（章鱼吸盘）, researchers from China and Switzerland have designed a needle-free alternative: a tiny, drug-filled, cup-like patch （贴片） that sticks to the inside of the cheeks. The device is easily accessible, and it can be removed at any time and the drug gets absorbed through the lining of the inner cheek, the team reports in a paper in Science Translational Medicine.
To test the design, the team 3D printed the suckers. They loaded each with the drug and stuck them inside the cheeks of three beagles, a kind of dog which has a similar inner cheek lining to humans. For comparison, they also delivered the drug to beagles via a pill. After three hours, the team found that drug blood concentrations in dogs with the patch were more than 150 times higher than in the dogs that took a tablet. They also found patches worked effectively for drugs with large molecules.
40 healthy human volunteers self-applied water-filled patches to see how well they would stay on while talking and moving their mouths. After 30 minutes, only five of the 40 patches had fallen off, which was because of improper placement. Most volunteers said they would prefer a patch over injections for daily applications.
Still, the team only tested the patch for a short time so they would need to find out what would happen if it was used repeatedly. They'd also need to determine which drugs would work with the technology: the target is large molecules, such as those used to treat obesity or osteoporosis, but they can't be too large to fit in the cup.
