Drug delivery devices could be powered by the body, say researchers
Led by Serge Cosnier, the team at Joseph Fourier, Grenoble, France, are the first to demonstrate a working synthetic glucose biofuel cell (GBFC) in an animal subject.
The cell comprises two electrodes – one to remove electrons from glucose, the other to deliver the electrons into oxygen molecules – in a pure carbon nanotube matrix, with a platinum wire to carry the current to the circuit.
It is then wrapped in a mesh that prevents enzymes escaping into the system.
The effect is a targeted oxidation to generate an electrical power output.
If plans for the new technology come to fruition, the artificial cell could wipe out the need for batteries in devices such as pacemakers, and Intraspinal drug delivery systems (IDDS) , which both require operations to replace worn out power cells.
Cases like that of Medtronic’s implantable drug delivery device – the SynchroMed II, used to deliver chronic pain medication such as baclofen – which struggled with failing batteries, would also be eradicated.
It could also provide a solution to stumbling blocks in powering new developments for artificial limbs that would otherwise require impractical battery power.
And unlike batteries, the cells have the potential to run indefinitely.
“A battery consumes the energy stored in it, and when it's finished, it's finished.
“A biofuel cell in theory can work without limits because it consumes substances that come from physiological fluids, and are constantly being replenished," Cosnier told the BBC website.
Mountains to climb
However, Cosnier is realistic about the obstacles left to face.
He told in-PharmaTechnologist: “Firstly, the technology remains to be investigated in body, and it should attain at least one year’s testing to have a medical interest.
“But to do this, we need first to improve and test our device on bigger animals in order to power an implanted device. This was not possible in rats.
“The second obstacle for us remains the power of the biofuel cell.”
In 2010, the team implanted GBFCs into rats. The electrodes were stable for 40 days in the extracellular fluid but only delivered 5 μW cm−2 – still far from that which is required to supply many implanted devices.
He said: “Today we can generate enough power to supply an artificial urinary sphincter, or pacemaker.
“We are already working on a system that can produce 50 times that amount of power, then we will have enough to supply much more demanding devices."
The researchers are now planning to test a bigger version of the platform in cows.
Cosnier told in-PharmaTechnologist he believes an additional two to three years assessing the device in bovine was necessary to realise its potential.
It will then be applied to monkey test subjects before being considered for human experimentation.
