Do you hate getting shots? If so, you’re not alone — and you may be in luck. Researchers are devising new, pain-free ways to deliver drugs. One is a robotic pill. Another is a medicine patch worn on the skin. Both are still in the early stages of development. But someday, these innovations could make delivering medicines more patient-friendly.
The new robotic pill comes out of a lab at the Massachusetts Institute of Technology in Cambridge. It holds a teeny, spring-loaded microneedle only about 3 millimeters (a tenth of an inch) long. Once swallowed, the pill injects medicine directly through the stomach wall.
Unlike a normal shot, this needle prick shouldn’t hurt, says Giovanni Traverso. He’s a physician and biomedical engineer who specializes in the gut. He also helped develop the robo-pill at MIT. Stomachs can detectsome sensations, such as the deep ache of a stomach ulcer. Or the discomfort of feeling bloated. But those sensations are “more related to stretch receptors,” Traverso explains. The stomach lacks receptors to detect sharp pains, such as an injection. Designing a pill that could reliably prick the stomach wall was a bit tricky. Once swallowed, the small but heavy device settles to the bottom of the stomach. In order to prick the stomach wall beneath it, the pill must land injector-side-down. To make that happen, the MIT team borrowed an idea from the leopard tortoise. Contrary to popular belief, most tortoises can get back on their feet if flipped upside-down. Leopard tortoises are aided by steeply domed shells. If one of them is flipped on its back, the shape of that shell helps it roll right-side up. That same shape ensures the new pill always lands upright, too.
Robert Langer is a chemical engineer on the MIT team. “Watch,” he says, as he drops a chickpea-sized robotic pill onto a table. It bounces, then rolls upright. “No matter how I drop it,” he notes — and he drops it again — “it always lands the same way.”
But what makes the pill’s tiny needle pop out to do its job? “Sugar glass,” Langer explains. Hard and brittle, this material holds back a spring that is attached to the needle. In the stomach, that sugar starts to dissolve. “All of a sudden, the thing breaks,” Langer says. This releases the spring, which jabs the needle into the stomach wall to inject medicine. It’s possible to control when that happens by adjusting the sugar’s thickness. This is a completely new way to deliver the drug, notes Bruno Sarmento. He works at the University of Porto in Portugal. Although he didn’t work on the pill system, as a nanomedicine researcher he’s interested in such projects. “We know now that it’s possible” for a robotic system to reach the stomach and deliver injections, he says. But he worries that the new pill may be too expensive for widespread use. Langer isn’t so sure. “I actually don’t know that it’ll be that expensive,” he says. Mechanized pills already exist. Langer points to a class known as osmotic pills. These pills have holes in them to pump drugs out. People might think they’d be a lot more expensive than regular pills, “but they really haven’t been,” he says. “When you start to make billions of these, the cost just goes way down.”
You must be logged in to post a comment.