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Ensuring that medicine is taken could start to tackle those issues – and a new smart pill developed at the Massachusetts Institute of Technology (MIT) could provide a way to do so.
Covered in a Nature Communications study today (8 January), the capsule contains a reporting system that sends a signal after it has been consumed. Designed to be incorporated into existing pill capsules, the system includes a biodegradable radio frequency (RF) antenna. Most of the components are designed to break down in the stomach after the notification is sent, while a tiny RF chip passes out of the body through the digestive tract.
The system could be useful for monitoring transplant patients who need to take immunosuppressive drugs, an MIT announcement suggested, or people with infections such as HIV or tuberculosis, who need treatment for an extended period of time.
“The goal is to make sure that this helps people receive the therapy they need to help maximise their health,” said Giovanni Traverso, an associate professor of mechanical engineering at MIT and senior author of the new study.
To make it easier for people to take their medication, Traverso’s lab previously worked on delivery capsules that can remain in the digestive tract for days or weeks, releasing doses at predetermined times. This approach might not be compatible with all drugs, however.
In the new study, the researchers focused on a strategy that would allow doctors to more closely monitor whether patients are taking their medication. Using radio frequency – which is safe for humans and can be easily detected from outside the body – they designed a capsule that can communicate after the patient has swallowed it.
The RF antenna is made from zinc and embedded into cellulose before being rolled up and placed inside a capsule along with the drug to be delivered. The outer layer of the capsule is made from gelatine coated with a layer of cellulose and either molybdenum or tungsten, which temporarily blocks any RF signal from being emitted.
“We chose these materials recognising their very favourable safety profiles and also environmental compatibility,” Traverso said.
Once the capsule is swallowed, the coating breaks down, releasing the drug along with the RF antenna. The antenna can then pick up an RF signal sent from an external receiver and, working with a small RF chip, send back a signal to confirm that the capsule was swallowed. This communication happens within 10 minutes of the pill being swallowed.
The RF chip, which is about 400 by 400 microns, is an off-the-shelf chip that is not biodegradable. All of the other components would break down in the stomach within a week, the announcement said.
Tests in an animal model showed that the RF signal was successfully transmitted from inside the stomach and could be read by an external receiver up to two feet away. If developed for use in humans, the researchers envision designing a wearable device that could receive the signal and then transmit it to the patient’s healthcare team. The team now plans to do further preclinical studies and hope to soon test the system in humans.
“One patient population that could benefit greatly from this type of monitoring is people who have recently had organ transplants and need to take immunosuppressant drugs to make sure their body doesn’t reject the new organ,” the announcement said.
“Other populations that could benefit include people who have recently had a stent inserted and need to take medication to help prevent blockage of the stent, people with chronic infectious diseases such as tuberculosis, and people with neuropsychiatric disorders whose conditions may impair their ability to take their medication.”
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