# Reduction of Intracochlear Trauma and Fibrosis Using Dual Network, Zwitterionic Hydrogel Thin Films on Cochlear Implant Surfaces

> **NIH NIH R01** · UNIVERSITY OF IOWA · 2024 · $581,274

## Abstract

Project Summary
Cochlear implant (CI) electrode arrays are made of platinum wires and contacts encased in a silastic housing.
These materials provide mechanical stability and flexibility critical to the long-term function of the CI. However,
they also induce local tissue reactions that can have detrimental effects. For example, trauma from insertion of
the CI can damage cochlear health and any residual acoustic hearing. Further, the fibrotic capsule that
encases CI electrode arrays leads to increased impedances and decreased signal resolution which reduce CI
effectiveness. Intracochlear fibrosis is also implicated in the loss of acoustic hearing that can occur months to
years after implantation. Thus, developing materials that mitigate insertion trauma and the inflammatory,
fibrous response to CI materials could significantly improve device function and safety. Ultra-low fouling
zwitterionic polymers are a new class of materials that show significant promise to eliminate fibrosis. However
as bulk materials they lack mechanical properties and long term durability suitable for use in CIs. To leverage
the ultra-low fouling surface properties of zwitterionic polymers while maintaining the proven mechanical
properties of current CI materials, we recently established a novel, patented photochemical process for
simultaneous polymerization, grafting and cross-linking of zwitterionic thin films on relevant CI materials. We
now leverage the mechanical advantages of recently developed dual network polymer technology to enhance
the strength of the thin films. We also use the thin films as novel drug delivery platforms with controlled and
sustained kinetics. We hypothesize that robust dual network, zwitterionic thin film coatings will maintain long-
term anti-fouling properties; reduce friction, insertion trauma, and intracochlear fibrosis; and provide controlled
sustained release of glucocorticoids. Accordingly, in Aim 1 we engineer robust, dual network zwitterionic thin
films for ultra-low fouling CI biomaterial coatings. Aim 2 investigates the effect of dual network, zwitterionic thin
film hydrogel CI coatings on tissue friction, insertion forces, cochlear trauma, and fibrosis using human cadaver
and sheep models. Finally, Aim 3 develops zwitterionic thin film hydrogel coatings with controllable, sustained
glucocorticoid delivery systems to reduce intracochlear inflammation and fibrosis in reporter mouse CI models.
Development of robust zwitterionic thin film coatings on implanted biomaterials that are lubricious, ultra-low
fouling, and capable of controlled and sustained drug delivery represents a transformative advance to prevent
trauma, reduce fibrosis, and improve the functional outcomes associated with placement of medical devices,
such as CIs, in the body.

## Key facts

- **NIH application ID:** 10913363
- **Project number:** 5R01DC012578-12
- **Recipient organization:** UNIVERSITY OF IOWA
- **Principal Investigator:** Allan Guymon
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $581,274
- **Award type:** 5
- **Project period:** 2013-03-04 → 2028-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10913363

## Citation

> US National Institutes of Health, RePORTER application 10913363, Reduction of Intracochlear Trauma and Fibrosis Using Dual Network, Zwitterionic Hydrogel Thin Films on Cochlear Implant Surfaces (5R01DC012578-12). Retrieved via AI Analytics 2026-05-28 from https://api.ai-analytics.org/grant/nih/10913363. Licensed CC0.

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