Over the past several years, we've heard about a number of implantable devices that regularly dispense medication within the body, doing away with the need for pills or injections. A new one takes things further, as its dosage level can be changed after it's been implanted.

Being developed at Texas' Houston Methodist Research Institute, the small, flat, battery-powered device is designed to be loaded with one or more types of medication, and then surgically implanted under a patient's skin. It then proceeds to release the drug(s) in precise amounts at controlled intervals that are specific to the patient, for up to a year before requiring a refill.

And should the patient require a change in dosage during that time, it can be arranged.

By externally transmitting a specific Bluetooth signal to the implant's microchip, doctors can alter the voltage that's applied to a silicon nanofluidic channel within the device. In lab tests, this allowed the scientists to switch it between standard, decreased or increased drug-release presets. It was dispensing medications used to treat rheumatoid arthritis and high blood pressure, which often have to be given at specific times of day and in varying dosages.

A Houston Methodist representative tells us that the device's drug-delivery functionality has so far been tested via in vitro experiments, although its ability to receive Bluetooth signals while implanted has been successfully tested in animals. The next step will be to implant it in animals, and then trigger and control its release of medication over a sustained period.

"We see this universal drug implant as part of the future of health care innovation," says Prof. Alessandro Grattoni, corresponding author of a paper on the research. "Some chronic disease drugs have the greatest benefit of delivery during overnight hours when it's inconvenient for patients to take oral medication. This device could vastly improve their disease management and prevent them from missing doses, simply with a medical professional overseeing their treatment remotely."

The paper was recently published in the journal Lab on a Chip.