In situ gene transfection and neuronal programming on electroconductive nanocomposite to reduce inflammatory response

Abstract

Inflammatory reactions, such as encapsulation of implanted electrodes by scar tissues and gradual degradation of neurons, are the key problems for neural tissue interfacing. These problems must be resolved for treatments of debilitating conditions to be effective. One strategy to mitigate them is to engineer neural electrodes with the ability to control cell response viain situgene transfection. Taking advantage of layer-by-layer (LBL) assembled carbon nanotube (CNT) composites, purposeful engineering of electrostimulating implants with these functionalities becomes realistic. LBL assembled CNT composites are conductive and can incorporate plasmid DNA capable of altering the response/functionality of surrounding cells. Successful expression of Lyn–citrine plasmid DNA was achieved in attached neurons. The transfection efficiency was found to be remarkably higher than conventional solution-mediated techniques. Most importantly, by using plasmid expression vectors for neural basic helix–loop–helix proteins, neurons were generated from multipotent P19 embryonal carcinoma cells adhering to the CNT multilayers. This study illustrates the possibility of fabricating an electrostimulating implant capable of recruiting and programming resident stem cells in the nervous system to provide a substantially improved level of tissue–device integration.