Your parents, your doctor, your spouse, or even your adult children constantly nag you: “Did you take your medicine? Did you take it on time? For crying out loud, did you take it all?"
Those aren’t silly worries. According to the website of the Alaska State Legislature, the failure to take medications on time at the correct dosage has massive consequences. Every year in the US alone, patients fail to take around half of their collective 2 billion prescriptions. A third take only some of their prescriptions, and another third never even fill them.
Why? One massive reason is that because about 21% of US patients can’t even afford their medication, and 66.5% of Americans cite medical costs as the chief cause of their bankruptcy. If you land in an American hospital, there’s a 10% chance it was due to medication “noncompliance” costing a collective $15.2 billion – and if you land in a nursing home, med-noncompliance as the cause soars to 23% at a cost of $31.3 billion.
But for people who can afford their prescriptions and have the mobility to get them fulfilled, a non-trivial reason for non-compliance is simply forgetting (worse for people taking medication for cognitive or neuropsychiatric impairments). So, what if your own pills could remind you if you’d taken them?
That’s the solution that an MIT team has delivered. In their Nature Communications paper “Bioresorbable RFID capsule for assessing medication adherence,” senior author Giovanni Traverso, and lead authors Mehmet Girayhan Say and Sean You, have revealed their new capsule design. Built with its own tiny radio frequency identifier (RFID), the capsule signals a receiver that it’s dissolving inside the body before the RF chip harmlessly exits the body (from exactly where you think it exits).
“The goal,” says Traverso, a gastroenterologist at Brigham and Women’s Hospital, and an associate professor of mechanical engineering at MIT, is to help “people receive the therapy they need to help maximize their health.”
The capsules, which can remain intact inside the digestive tract for weeks, are able to release their medications on a schedule. The new system is particularly useful for monitoring people with chronic infections requiring long-term treatment, or transplant patients on immunosuppressive drugs (without which tissue-rejection remains a potentially lethal risk).
While other researchers have previously developed RFID capsules, the human digestive tract couldn’t disintegrate them, so all their components needed to travel the length of the body and exit in feces, or accumulate inside the body. But the commercially-available 400 x 400-micrometer unit inside the MIT design is bioresorbable, with a zinc-cellulose antenna that humans can digest. As Traverso says, “We chose these materials recognizing their very favorable safety profiles and also environmental compatibility.”
So, how does the capsule know when to send its signal? Made from a digestible mixture of cellulose, gelatin, and molybdenum or tungsten, the capsule works as a tiny Faraday cage, blocking RF communication. But within 10 minutes of landing and dissolving inside the GI tract, the capsule starts releasing not only its medicine, but its RF signals – which in animal experiments could reach a receiver 60 cm away – announcing “mission accomplished.” After a week, the device is totally gone.
“Our goal is to avoid long-term accumulation [of swallowed materials] while enabling reliable confirmation that a pill was taken," says co-lead author Say. If development is successful with humans, Say’s team says that the capsule could communicate with a wearable medical monitor that could notify a patient’s medical team.
This new capsule isn’t the only recent MIT innovation in minute medical devices; recently another team developed an origami-like structure (which can also work at macro-scale for other uses such as emergency shelters) that could expand inside the body after injection, suggesting a small-is-big future for medical miniaturization.
Source: MIT
