Fully flexible implantable neural probes for electrophysiology recording and controlled neurochemical modulation.

Targeted delivery of neurochemicals and biomolecules for neuromodulation of brain activity is a powerful technique that, in addition to electrical recording and stimulation, enables a more thorough investigation of neural circuit dynamics. We have designed a novel, flexible, implantable neural probe capable of controlled, localized chemical stimulation and electrophysiology recording. The neural probe was implemented using planar micromachining processes on Parylene C, a mechanically flexible, biocompatible substrate.

Electrically Controlled Vasodilator Delivery from PEDOT/Silica Nanoparticle Modulates Vessel Diameter in Mouse Brain.

Vascular damage and reduced tissue perfusion are expected to majorly contribute to the loss of neurons or neural signals around implanted electrodes. However, there are limited methods of controlling the vascular dynamics in tissues surrounding these implants. This work utilizes conducting polymer poly(ethylenedioxythiophene) and sulfonated silica nanoparticle composite (PEDOT/SNP) to load and release a vasodilator, sodium nitroprusside, to controllably dilate the vasculature around carbon fiber electrodes (CFEs) implanted in the mouse cortex.

Stable in-vivo electrochemical sensing of tonic serotonin levels using PEDOT/CNT-coated glassy carbon flexible microelectrode arrays.

Chronic sampling of tonic serotonin (5-hydroxytryptamine, 5-HT) concentrations in the brain is critical for tracking neurological disease development and the time course of pharmacological treatments. Despite their value, in vivo chronic multi-site measurements of tonic 5-HT have not been reported. To fill this technological gap, we batch-fabricated implantable glassy carbon (GC) microelectrode arrays (MEAs) onto a flexible SU-8 substrate to provide an electrochemically stable and biocompatible device/tissue interface.

Melatonin Decreases Acute Inflammatory Response to Neural Probe Insertion.

Neural electrode insertion trauma impedes the recording and stimulation capabilities of numerous diagnostic and treatment avenues. Implantation leads to the activation of inflammatory markers and cell types, which is detrimental to neural tissue health and recording capabilities. Oxidative stress and inflammation at the implant site have been shown to decrease with chronic administration of antioxidant melatonin at week 16, but its effects on the acute landscape have not been studied.