An Electrically Conductive DNA-Inspired Coating for Neural MEA Interfaces

MEAs provide crucial insight into the electrical function of the nervous system and other electrically excitable tissue types. However, poor bio-integration remains a major challenge for intracortical microelectrodes due to lack of biocompatibility between implanted electrode materials and native neural tissue. Poor biocompatibility will result in a reduction in healthy neuron attachment following acute-phase implantation, which will impact the chronic-term success of the MEA. Families of MEA coatings have been developed to facilitate the integration of brain and device including, conductive polymers, carbon nanotubes, and bioactive hydrogels. Many of these coating materials possess biological, functional or electrochemical disadvantages that impede microelectrode efficacy. Herein lies the incentive to develop novel nanomaterials capable of coating MEAs to improve tissue integration while maintaining the functionality of bioelectronic interfaces.<br/> <br/>Therefore, we developed Janus base nanotubes (JBNts), a family of Janus base nanomaterials (JBNs) self-assembled from G^C or A^T units mimicking DNA base pairs. The G^C monomers may also be conjugated with amino acid moieties that influence supramolecular chirality and electrostatic properties upon self-assembly into rosettes. Non-covalent interactions including hydrogen bonding, the hydrophobic effect, and the π-π stacking effect drives rosettes on top of one another forming a nanotubular structure with a high density of outfacing amino acids. These nanotubes (JBNts) are &lt;1nm in diameter and can self-assemble upwards to multiple microns in length. A key feature of JBNt self-assembly lies between the aromatic rings that constitute the nanotubes core. Core aromaticity allows π electron mobility around the 10-carbon system, effectively creating π electron clouds below and above each assembled JBNt rosette, enabling electrical conductivity. Our results demonstrate that JBNts utilize long-distance electron dislocation via π-π rosette stacking to maintain electrochemical activity during cyclic voltammetry, impedance testing and pseudo-neural signal recording on MEAt. JBNTs also enhance interface integration including differential protein expression that encourage neural outgrowth and neuron maturation. In vivo results demonstrate JBNt biocompatibility during in vivo interface studies. We anticipate these results will serve as a benchmark for the continued development and study of JBNt to enhance interface dynamics and ultimately the performance and reliability of brain microelectrodes.