Multifunctional Nanobiomaterials for Neural Interfaces

TLDR

Neural electrodes are designed to interface with the nervous system for prostheses, yet chronic recording and stimulation remain unreliable. This study introduces a new fabrication method for soft, low‑impedance, high‑charge‑density nanobiomaterials that can be applied to neural microelectrodes to stabilize the electrode‑tissue interface. The method combines electrospinning dexamethasone‑loaded biodegradable nanofibers, coating them with alginate hydrogel, and electrochemically polymerizing conducting polymers to form nanotube and cloud‑like nanostructures. The resulting 3‑D conducting polymer nanostructures lower electrode impedance, increase charge‑capacity density, and the alginate coating moderates dexamethasone release, reducing burst effects, making the materials promising for diverse electrode‑tissue interfaces.

Abstract

Abstract Neural electrodes are designed to interface with the nervous system and provide control signals for neural prostheses. However, robust and reliable chronic recording and stimulation remains a challenge for neural electrodes. Here, a novel method for the fabrication of soft, low impedance, high charge density, and controlled releasing nanobiomaterials that can be used for the surface modification of neural microelectrodes to stabilize the electrode/tissue interface is reported. The fabrication process includes electrospinning of anti‐inflammatory drug‐incorporated biodegradable nanofibers, encapsulation of these nanofibers by an alginate hydrogel layer, followed by electrochemical polymerization of conducting polymers around the electrospun drug‐loaded nanofibers to form nanotubes and within the alginate hydrogel scaffold to form cloud‐like nanostructures. The three‐dimensional conducting polymer nanostructures significantly decrease the electrode impedance and increase the charge capacity density. Dexamethasone release profiles show that the alginate hydrogel coating slows down the release of the drug, significantly reducing the burst effect. These multifunctional materials are expected to be of interest for a variety of electrode/tissue interfaces in biomedical devices.