# Microelectrodes for Co-Localized Tunable Drug Delivery and Neural Recording

> **NIH VA I01** · LOUIS STOKES CLEVELAND VA MEDICAL CENTER · 2022 · —

## Abstract

Each year, thousands of Veterans experience neurologic injury or disease resulting in severe motor
dysfunction, with devastating consequences for the affected individual and their loved ones. Intracortical
brain-machine interfaces (iBMIs) offer a compelling solution for restoring volitional control of computer
cursors, robotic arms, and functional electrical stimulation-controlled limbs. However, iBMI functionality is
reliant upon our ability to detect neuronal signals at indwelling microelectrodes for a period of years to
decades. This requirement is challenged by the biological response to the implant, which impedes
communication between healthy neurons and the implanted microelectrodes. Successful iBMI clinical
translation, and the resulting gains in functional independence for users, hinges upon improving the quality
and stability of the biotic-abiotic interface.
 The standard materials used for intracortical microelectrode devices are rigid materials, such as silicon,
which can cause chronic tissue damage that exacerbates the biological response. Some groups have developed
flexible polymer-based devices, though these usually require reinforcement to prevent buckling during
insertion. Local pharmacologic delivery can also be used to control the tissue response, though is typically
either short-lived as drug-loaded coatings are depleted, or requires complex and invasive fluidic systems.
 Our approach combines advanced structural and microelectrode materials to provide a two-pronged
approach to attenuating the inflammatory tissue response without requiring complex fluidic delivery systems.
A mechanically-adaptive polymer nanocomposite (NC) provides a structural material that is sufficiently stiff
insert into the cortex, yet dramatically softens within minutes of insertion to minimize chronic differential
tissue strain. Highly-ordered, vertically-oriented titania nanotube arrays (TNAs) will perform both drug-
releasing intracortical microelectrode recording sites. TNAs are highly tunable materials that can efficiently
store pharmacologic agents that slowly diffuse into tissue over weeks to months with a release profile governed
by the nanotube geometries. Chemical doping processes enhance TNA conductivity to facilitate sensing
neuronal activity. We hypothesize that combining soft structural materials with sustained anti-inflammatory
drug delivery will lead to synergistic improvements in tissue response and long-term neural recording quality.
 We will first investigate the relationship between anti-inflammatory release kinetics and the inflammatory
response. Devices comprise TNA microsegments integrated into the NC. Dexamethasone, a representative anti-
inflammatory corticosteroid, will be loaded into either the NC or into the TNAs to provide rapid and sustained
(>8 weeks) release profiles, respectively. Devices will be implanted into wild-type mice for up to 1, 2, 4 or 8
weeks. At each timepoint, local inflammatory markers in tissue will be eval...

## Key facts

- **NIH application ID:** 10538836
- **Project number:** 1I01RX003950-01A1
- **Recipient organization:** LOUIS STOKES CLEVELAND VA MEDICAL CENTER
- **Principal Investigator:** Allison Hess Dunning
- **Activity code:** I01 (R01, R21, SBIR, etc.)
- **Funding institute:** VA
- **Fiscal year:** 2022
- **Award amount:** —
- **Award type:** 1
- **Project period:** 2022-11-01 → 2026-10-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10538836

## Citation

> US National Institutes of Health, RePORTER application 10538836, Microelectrodes for Co-Localized Tunable Drug Delivery and Neural Recording (1I01RX003950-01A1). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10538836. Licensed CC0.

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