Preliminary study of neurite outgrowth within polyimide microtubes

The cone electrode first developed by P.R. Kennedy paved headway in the area of cortical prostheses. While effective, to date, no optimization of the materials, length, diameter or controlling neurotrophic effects have been extensively quantified for such systems. This paper describes an in-vitro model system for the study of neurite outgrowth using PC-12 cells and an array of polyimide microtubes. Our aim is to obtain preliminary design specifications for the eventual optimization of in-vivo neurotrophic electrodes. We performed preliminary characterization of the number and average lengths of PC-12 neurites that penetrated into the tubes mounted within a standard Petri dish. To describe system performance, we observed an increase in the average number of neurites that grew into the tubes over a period of days. We also observed an increase in the average length of the neurites (with a 95% confidence) between day 3 and day 4 of between 14.97 microm and 62.27 microm. In addition, we measured a length change (with a 95% confidence) between day 4 and day 6 of 93.51 microm and 145.45 microm. These results will soon be augmented by quantification of neurites using a photo lithographically patterned glass microgroove system.