injected gel transforms into an electrode in the brain

Article in De Volkskrant, by Maarten Keulemans, d. Febr. 23, 2023. (shamelessly and automatically) translated and posted somewhere else by Mildred

It could well mark the beginning of ‘a new paradigm in bioelectronics’, the researchers boast themselves. ‘For decades we have tried to make electronics that mimic biology. Now we let biology itself do the electronics for us,” said study leader Magnus Berggren of Linköping University in a media statement.

The scientists made a gel from various substances that, once injected into zebrafish, string together into electrically conductive threads in about ten minutes, under the influence of, among other things, sugars that occur naturally in the body. Ideal for, for example, exorcising certain brain diseases, stimulating nerves or eavesdropping on brain regions and organs, the Swedes think.

Small wounds

A fascinating way to reach vulnerable places in the body that cannot be reached with ordinary electrodes, also thinks bioelectronics professor Wouter Serdijn (TU Delft). After all, normal, stiff electrodes can cause wounds and cause small inflammations.

Serdijn also sees the limitations of the new technique: ‘It is important to realize that these electrodes are not insulated. So they make contact with every tissue with which they are connected. That leads to electrical losses and loss of resolution.’

Bioelectrodes are already being used in all kinds of areas in the body. A well-known application is deep brain stimulation. In addition, disorders such as Parkinson’s disease, epilepsy or Tourette’s syndrome are inhibited by administering electrical impulses to specific brain areas with electrodes inserted deep into the brain.

Incidentally, the new electrodes themselves ‘can’t do anything. ‘They are a kind of plugs, they only make electrical contact’, Serdijn observes. ‘For fully implantable electronics you also need transistors to amplify weak nerve signals and do calculations on them, to stimulate nerves or to be able to communicate wirelessly with the implant. And as far as I know nobody has grown transistors and certainly not circuits in tissue.’

brain paste

The Swedish team tested the electrodes in fish, medicinal leeches and in the loose muscles of mammals. The method promises to “blur the distinction between biological and technological or electronic materials and systems,” the group said in the journal Science.

But Serdijn would still like to temper that expectation. The point, he explains, is that brain cells and electronics work completely differently. It is not as simple as ‘just’ connecting them together. “These are two different worlds, which by nature don’t talk to each other. The technology should actually learn to speak the language of the brain more. And brain cells must become more receptive to what technology has to offer.’

In the US, Tesla boss Elon Musk founded the company Neuralink five years ago to connect brains with electronics, so far without success. ‘I once thought: it would be smarter to smear some kind of cerebral paste over your cerebral cortex and let it grow,’ Serdijn muses. ‘Then you have an extension that does speak the same language.’