The boundaries between biology and technology are blurring. Researchers at Sweden’s Linköping University, Lund University, and Gothenburg University have successfully grown electrodes into living tissue using body molecules as triggers.
The results, published in Science, pave the way for the formation of fully integrated electronic circuits in vivo.
“For decades we have tried to make electronics that mimic biology. (LOE) Professor Magnus Berggren said.
Linking electronics to living tissue is critical for understanding complex biological functions, combating diseases in the brain, and developing future interfaces between humans and machines. However, conventional bioelectronics developed in tandem with the semiconductor industry have fixed, static designs that are difficult, if not impossible, to combine with living biological signaling systems. .
To bridge this gap between biology and technology, researchers have developed a method to create soft, substrate-free, electronically conductive materials within living tissue. By injecting gels containing enzymes as ‘assembly molecules’, researchers were able to grow electrodes in zebrafish and medicinal leech tissue.
“When in contact with a substance in the body, the structure of the gel changes, making it a different conductivity than it was before injection. Depending on the tissue, we can also adjust the composition of the gel to initiate electrical processes,” he says. Xenofon Strakosas, a researcher at LOE and Lund University and one of the study’s lead authors.
Endogenous molecules in the body are sufficient to trigger the formation of electrodes. It does not require genetic modification or external signals such as light or electrical energy, which were required in previous experiments. A Swedish researcher is the first in the world to succeed in this.
Their work paves the way for new paradigms in bioelectronics. Previously it was necessary to implant a physical object to initiate electronic processes in the body, but in the future injection of a viscous gel will suffice.
In their work, the researchers further show that this method can target electronically conductive materials to specific biological substructures, thereby creating interfaces suitable for neural stimulation. In the long term, it may be possible to fabricate fully integrated electronic circuits in vivo.
In experiments conducted at Lund University, the team successfully formed electrodes around zebrafish brains, hearts and tail fins, as well as nerve tissue in medicinal leeches. Animals were neither harmed by the injected gel nor affected by electrode formation. One of the many challenges in these trials was taking into account the animal’s immune system.
“By making smart changes to the chemistry, we were able to develop electrodes that were accepted by brain tissue and the immune system. Zebrafish are an excellent model for studying organic electrodes in the brain,” he said. Professor Roger Olsson of the Lund University School of Medicine, who has a chemistry lab at the University of Gothenburg, said.
The research was spearheaded by Professor Roger Olsson after reading about an electronic rose developed by Linköping University researchers in 2015. One research question, and an important difference between plants and animals, was the difference in cell structure. Plants have rigid cell walls that allow the formation of electrodes, whereas animal cells resemble soft masses. Making the gel was a challenge that took years to solve.
“Our results open the door to a whole new way of thinking about biology and electronics. While many questions remain to be solved, this work is a good starting point for future research.”
Original: Electrodes grown in the brain – paving the way for future treatments for neurological disorders
Than: Linköping University | Lund University | Gothenburg University
