By E&T editorial staff

Electronic pills and drug implants that can be activated remotely could be closer to reality with the discovery of a new material that uses electrical signals to capture and release biomolecules.

Developed by researchers from Chalmers University in Sweden, the material is a polymer surface that changes state from capturing to releasing biomolecules when an electric pulse is introduced.

The material also functions in biological fluids with a buffering capacity, in other words fluids with the ability to counteract changes in the pH value. This property paves the way for the creation of a new technique for implants and electronic 'pills' that release the medicine into the body via electronic activation.

“You can imagine a doctor, or a computer program, measuring the need for a new dose of medicine in a patient, and a remote-controlled signal activating the release of the drug from the implant located in the very tissue or organ where it’s needed,” said Gustav Ferrand-Drake del Castillo, lead author on the study.

Locally activated drug release is available today in the form of materials that change their state in the event of a change in the surrounding chemical environment. For example, tablets of pH-sensitive material are produced where you want to control the release of a drug in the gastrointestinal tract, which is an environment with natural variations in pH value. But in most of the body’s tissues there are no changes in pH value or other chemical parameters.

“Being able to control the release and uptake of proteins in the body with minimal surgical interventions and without needle injections is, we believe, a unique and useful property. The development of electronic implants is only one of several conceivable applications that are many years into the future. Research that helps us to link electronics with biology at a molecular level is an important piece of the puzzle in such a direction,” said del Castillo.

Another advantage of the new method is that it does not require large amounts of energy. The low power consumption is due to the fact that the depth of the polymer on the surface of the electrode is very thin, on the nanometre scale, which means that the surface reacts immediately to small electrochemical signals.

“Electronics in biological environments is often limited by the size of the battery and the moving mechanical parts. Activation at a molecular level reduces both the energy requirement and the need for moving parts,” del Castillo added.

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