Design And Evaluation Of An Immnunoevasive Carbon Nanotube Sheet-collagen Composite Neural Electrode
Abstract
Currently, long term neural interfacing is hindered by instability of the neural electrode-tissue interface. Many modes of electrode failure have been reported, though the tissue response to the foreign electrode body is commonly recognized as a major contributor. The encapsulation of electrode by fibrous tissue and a progressive inflammatory reaction leads to local neurodegeneration and isolation of the electrode from the electrically active tissue. To address this mechanism of failure, a new electrode material is presented and evaluated that uses low immunogenic carbon nanotube sheets that have been shown to be non-cytotoxic and promote neural growth as nanoscale electrode sites. It is proposed that because immune response on this scale typically occurs by molecular recognition, reducing the size of the site of charge exchange with the tissue to the nano-scale may potentially avoid the pathways that lead to the formation of an electrode isolating fibrous capsule. The design, characterization, and in vivo testing of such an electrode are presented.