Dr Manus Biggs and Dr Alex Trotier. Image: Lindsay Deely
A study from the Cúram research centre suggests that tiny movements cause friction and inflammation in brain tissue surrounding an implant, which could be fixed by coating these devices in soft gels.
Research at the University of Galway may be able to stop brain implants from losing their functionality after they are placed into living tissue.
Brain implants have vast potential, with early prototypes promising ways to help paralysed people regain control of their limbs or control a computer keyboard with their thoughts.
But work is still ongoing in this field and researchers at Cúram – the Science Foundation Ireland Research Centre for Medical Devices based at the University of Galway– said these implants are difficult to engineer and often lose their functionality after they are surgically implanted.
A recent study from these researchers suggests that motions from everyday bodily functions – such as breathing and the pulse from the heart – may be the issue. The research suggests that cells in the brain sense the continuous motion from these functions and that these small movements can lead to friction and inflammation for brain tissue surrounding a brain implant.
This friction and inflammation can kill off vital brain cells and cause scarring, which also limits the functionality of the brain implant.
Dr Alex Trotier, who carried out the principal research of the study, said mitigating this scarring is “critical” for the development of brain-computer interfaces.
“The scar tissue that develops around an implanted neural device prevents brain signals from being recorded, rendering the device useless,” Trotier said. “The potential gamechanger here is for the development of digital implants which can read the brain electrical activity for years at a time.”
The study also found that brain cells attempt to protect themselves from continuous friction by keeping their distance from hard brain implants – by creating a fluid-filled blister to prevent direct contact.
The Cúram researchers said these blisters protect the brain cells from damage, but also prevent the neural recording device from operating.
The research suggests that anti-inflammation approaches could be used to prevent this scarring, such as by coating brain implants with soft gels that reduce implant friction and ensure a slow release of these drugs.
Dr Manus Biggs, the lead researcher of the study and a Cúram investigator, said it was “exciting” to discover that brain cells use “specialised sensors” to respond to small frictional forces and how tiny movements can disrupt brain implants.
“It is hoped that by understanding the cellular repair mechanisms, which occur following the introduction of a brain implant, that novel devices or drugs can be developed which prevent the scarring and blistering process, paving the way for the emergence of exciting devices which can link the mind directly with advanced technologies,” Biggs said.
Moving into human trials
The research comes at a crucial point in the field of brain implants, with multiple companies testing protypes on humans. For example, Neuralink – the brain implant company founded by Elon Musk – revealed last September that it is looking for candidates to take part in a human clinical study.
Neuralink received approval from the US Food and Drug Administration in May 2023 to run clinical trials on humans, in the form of an investigational device exemption. This allows devices to be used in a clinical study in order to collect “safety and effectiveness data”.
But the company has faced federal investigation in the US for potential animal welfare violations during its trials.
A Reuters report in December 2022 based on records and sources with direct knowledge of the company’s animal-testing operations found that Neuralink had killed about 1,500 animals, including more than 280 sheep, pigs and monkeys.
The investigation followed internal staff complaints around how the company was allegedly rushing its animal testing, resulting in botched experiments. Neuralink denied these claims last year.
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