Chronic Nerve Interfacing Utilizing Graft-Embedded Regenerative Macro-Sieve Electrodes

Custom-designed macro-sieve electrodes represent a novel means of facilitating chronic high specificity nerve stimulation needed to control distal nerve musculature and restore sensorimotor function. Implantation of these electrodes requires the transection of the nerve, which has shown to disrupt muscle fiber distribution. This present study assesses the feasibility of implementing these electrodes in an end-to-side nerve graft. The macro-sieve electrodes were fabricated and micro-surgically implanted into 3.2 cm nerve autografts harvested from the sciatic nerve of 12 male Lewis rats. Electrode-enabled nerve grafts were micro-surgically implanted in an end-to-side manner into donor rat sciatic nerves without the need for a transection of the host nerve. The nerve interface was assessed by selectively stimulating regenerated nerve tissue via implanted sieve electrodes while simultaneously mapping evoked muscle activation and force production at 3 months post-operatively. Micro-surgical implantation of nerve grafts and conduit-based nerve grafts into the sciatic nerve of healthy male rats of 3 months resulted in robust axonal regeneration. The electrode-enabled nerve grafts implanted in the sciatic nerve of healthy male rats showed signs of axonal regeneration through the macro-sieve electrode. Electrophysiological assessment showed preservation of motor function 3 months post-operatively