Science: Nanotechnology meets radio physics for wireless medicine
Cells, drugs and even animals can now be made to respond to wireless signals. Meet the pioneers of remote-controlled medicine.
Barely a millimetre long, Arnd Pralle’s nematodes look much like any other worms. Then he switches on a magnetic field. The slithering, wriggling nematodes halt and, after a moment’s hesitation, go into reverse. He flicks the field off and on again and the creatures dance to his tune, moving back and forth in synchrony.
These are remote-controlled worms. Pralle and his colleagues at the State University of New York in Buffalo have implanted nano-sized receivers in nerve cells in the nematodes’ heads. Whenever the receivers detect the high-frequency magnetic field, the neurons fire and the worms turn.
Pralle’s nematodes are just the beginning. Biologists are now targeting other hosts and implanting receivers in ion channels, DNA strands and antibodies. Their aim is to take charge of living cells using little more than radio waves.
This emerging field – a confluence of nanotechnology, biology and radio physics – is proving to be a powerful research tool but it is also creating a new kind of science: call it wireless bioengineering or electromagnetic pharmacology, if you will. Whatever the label, researchers are increasingly turning on and tuning in, and the implications are huge.
A new branch of medicine is on the horizon, says physicist Bernardo Barbiellini-Amidei from Northeastern University in Boston, who helped to organise a US National Science Foundation workshop on the subject last year. Any number of treatments – based on the immune system, on gene therapy or even stem cells – could potentially be controlled remotely. Wirelessly activated medication could offer a nearly instantaneous on-off switch, in contrast to conventional drugs that can take hours to act and which linger in the body.
“Imagine using radio fields to trigger cells to supply therapeutic proteins that are costly or difficult to deliver by other means,” says Sarah Stanley of Rockefeller University in New York, one of a team that has already developed a way to control the production and release of insulin using radio waves. It is perhaps not even too far-fetched to imagine a generation of drugs that start to work when activated by a smartphone app.
“Nanoscale wireless systems have tremendous potential for medical therapeutics,” says Barbiellini-Amidei.
Powerful magnetic fields are already used as therapy for some illnesses. For example, a technique called transcranial magnetic stimulation (TMS) is approved in the US as a treatment for depression. It works by inducing localised electric currents in the brain.
Philip Ball, New Scientist