January 8, 2015

expert reaction to neural implants in rats with paralyzing spinal cord injury

A study published in the journal Science have used electrical and chemical stimulation to recapitulate movement in rats with spinal cord injury. They report the use of an implant on the surface of the brain or spinal cord, which is also able to monitor output from the brain.

Prof. John Hunt, Head of Unit of Clinical Engineering, University of Liverpool, said:

“This study in rats is an interesting one and it could have the potential to be quite promising in terms of being applicable to people with spinal injuries. However, we don’t know that yet – not only because this study is in rats, not in man, but also because this study is not long-term enough to be sure about biocompatibility and efficacy of the implanted material, i.e. we don’t yet know that these implants wouldn’t become fibrotic.  The biocompatibility studies in this paper appear to have only been done for six weeks (Figure 2 is an example). This is not long term for an implanted biomaterial. Typically we would expect to implant materials intended to last a “lifetime in man” for at least 18 months in rats, to test safety and efficacy.  Hopefully such studies will follow, but we are not there yet.”

Dr Dusko Ilic, Reader in Stem Cell Science, King’s College London, said:

“The scientist designed and fabricated a superelastic prosthesis tailored specifically to get in intimate contact with the spinal cord. The implant has embedded electrodes and a drug delivery system that enables delivery of therapeutic stimuli and/or agent to the injured spinal cord. This implant, termed “e-dura”, was tested on healthy rats and rats with spinal cord injury. Healthy rats tolerated presence of the e-dura prosthesis for 5 weeks without any side effects. This is quite remarkable; until now, the most advanced prostheses in intimate contact with the spinal cord caused quite substantial damage to tissue in just one week due to their stiffness. They also demonstrated that e-dura implants seem to ameliorate symptoms of spinal cord injury in the rat model.

“The work described here is a groundbreaking achievement of technology, which could open a door to a new era in treatment of neuronal damage. However, there is still a long way to go before we may see any practical use of such neuroprostheses in humans. But it may be that it is something that could potentially be developed for use in humans in the foreseeable future.”

‘Electronic dura mater for long-term multimodal neural interfaces’ by Ivan R. Minev et al. published in Science on Thursday 8 January 2015. 

Declared interests

None declared