Neural interfaces allow the establishment of connections between the nervous system and external electronics, and hold great potential in both the clinic and basic research. The peripheral nervous system is a particularly attractive site to position an interface. Nerves are easy to access surgically and action potentials carried by them correlate well with activity at their target. Although many designs for peripheral nerve interfaces have been developed, they all face a major challenge upon chronic implantation. Materials used in implants are orders of magnitude stiffer than most tissues, which tags them as foreign. As a result, the body responds to interface implantation with inflammation and fibrosis – a foreign body reaction – damaging the nearby fragile nervous tissue. This currently limits the long-term use of neural implants in vivo.
In order to avoid this foreign body reaction, we are testing low-stiffness materials as potential components for neural interface manufacture. Work in our lab has shown that in the rodent central nervous system this rejection process is linked to the stiffness mismatch between tissue and implant. My current work aims to determine whether this also holds true for the peripheral nervous system - which houses a different set of cell types – and to exploit this finding by developing a mechanically compliant nerve prosthesis.
This project is carried out under the supervision of Dr Kristian Franze (PDN) and Professor James Fawcett (Clinical Neurosciences).