An ideal neural interface should mimic physiochemical properties of neural tissue and create a chronic bi-directional communication with nervous system. The quality of the interface ultimately rests on the material properties that can enable a long-lasting functional device. Existing neural electrodes utilize conventional inorganic materials that are not intrinsically compatible with biological tissue and lead to substantial reactive tissue responses at electrode-tissue interact. Conducting polymers (CPs) such as poly(pyrrole) and Poly(3,4-ethylenedioxythiophene) have widely used for neural applications owing to their 1) soft mechanical properties that simulate those of biological structures; 2) mixed electronic/ionic conductivity that promotes efficient signal transduction; 3) transparency that allows the simultaneous use of optical analysis techniques; and 4) facile functionalization with biomolecules to tune biological response.
In this study, we investigate the ability bioactive conducting polymer nanotubes (CPN) to direct the extension of neural processes. The fabrication process includes (1) electrospinning of poly (l-lactic acid) (PLLA) template nanofibers from 3% wt PLLA/chloroform solution at 100 kV/m electrical field, (2) electrochemical polymerization of laminin-doped poly(3,4-ethylenedioxythiophene) (PEDOT) from 0.02M PEDOT and 6.17µM laminin-derived peptide (DEDEDYFQRYLI) solution with charge density 600mC/cm2, and (3) removing the PLLA template nanofibers. The size of PLLA fibers was 302.65±101.66 nm diameter (n=100). The X-ray photoelectron spectroscopy (XPS) results have proved the presence of laminin-derived peptide on the surface of CPN. We characterized the electrical properties (i.e. impedance and capacity of charge transfer) of the bioactive CPN. We will use rat dorsal ganglions to study the effect of laminin-doped CPN on growth of neuronal cells and neurite outgrowth. Future study will focus on creating a gradient of human laminin on the surface of CPN as a guidance cue for axonal guidance.