Publications

Ten peer-reviewed papers, newest first.

Every result on this site comes from a published paper, a dissertation or an issued patent. Each link below goes to the journal page through its DOI.

Peer-reviewed papers

Published
Photografted dual-network zwitterionic hydrogel coatings for biomaterials
Barrera G, Wu A, Peel A, Elmer N, Hansen KR, Xu L, Hansen MR, Guymon CA. ACS Applied Polymer Materials 2026;8(18):16328-16338.
A second, interpenetrating network makes the zwitterionic coating tougher and less swollen while keeping its antifouling; in rats, capsules around coated silicone were about 75 percent thinner at six weeks.
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Published, open access
Development of zwitterionic hydrogel thin film coatings of cochlear implant electrode arrays that reduce intracochlear inflammation and electrode impedance
Ben-Shlomo N, Peel A, Etler C, et al. Hearing Research 2026;474:109606.
Human cochlear implant arrays with the coating read about half the electrode impedance of uncoated arrays in sheep, and the cochlea showed less inflammation at four weeks.
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Published, open access
Enhancing Mucus Flow and Clearance by Grafting Zwitterionic Hydrogel Films to Luminal Surfaces
Horne R, Escudero C, Ellerman M, Guymon CA, Hansen M. Laryngoscope Investigative Otolaryngology 2025;10(2):e70118.
On the bench, mucus began to flow at a gentler tilt on coated silicone sheets and tubes, and a dried mucus plug cleared sooner in a preliminary test.
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Published, open access
Photografted Zwitterionic Hydrogel Coating Durability for Reduced Foreign Body Response to Cochlear Implants
Peel A, Bennion D, Horne R, Hansen MR, Guymon CA. ACS Applied Bio Materials 2024;7:3124-3135.
The coating kept its low friction after three weeks in mice, after drying and rewetting, and under repeated bending. Coated arrays needed about half the peak force to enter human cadaver cochleae.
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Published
Reducing the foreign body response on human cochlear implants and their materials in vivo with photografted zwitterionic hydrogel coatings
Horne R, Ben-Shlomo N, Jensen M, et al. Acta Biomaterialia 2023;166:212-223.
In mice, coated silicone and coated human implant arrays had thinner scar capsules than uncoated ones, and the film was still intact after one year.
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Published
Zwitterionic Photografted Coatings of Cochlear Implant Biomaterials Reduce Friction and Insertion Forces
Bennion DM, Horne R, Peel A, et al. Otology and Neurotology 2021;42(10):1476-1483.
The coating cut friction on silicone by more than 90 percent and cut the peak force to insert an electrode into human cadaver cochleae by about 40 percent.
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Published, open access
Antifouling and Mechanical Properties of Photografted Zwitterionic Hydrogel Thin-Film Coatings Depend on the Cross-Link Density
Jensen MJ, Peel A, Horne R, et al. ACS Biomaterials Science and Engineering 2021;7(9):4494-4502.
The amount of cross-linker sets how stiff the film is and how well it resists protein, cells and friction. The best balance in the lab came at roughly 5 to 15 percent cross-linker.
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Published
Photograftable Zwitterionic Coatings Prevent Staphylococcus aureus and Staphylococcus epidermidis Adhesion to PDMS Surfaces
Shen N, Cheng E, Whitley JW, et al. ACS Applied Bio Materials 2021;4(2):1283-1293.
Coated silicone held far fewer S. aureus and S. epidermidis in the lab. In rats it carried fewer bacteria 21 days after implantation.
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Published
Antifouling Photograftable Zwitterionic Coatings on PDMS Substrates
Leigh BL, Cheng E, Xu L, Derk A, Hansen MR, Guymon CA. Langmuir 2019;35:1100-1110.
A one-step UV process grafts a cross-linked film onto silicone that cuts protein and fibroblast adhesion in the lab and fails inside the gel before it fails at the silicone.
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Published
Photopolymerizable Zwitterionic Polymer Patterns Control Cell Adhesion and Guide Neural Growth
Leigh BL, Cheng E, Xu L, Andresen C, Hansen MR, Guymon CA. Biomacromolecules 2017;18(8):2389-2401.
Coated stripes on glass kept protein and cells off, and nerve fibers grew in straight lines along 100 micrometre stripes.
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Dissertations

PhD theses from the University of Iowa, Department of Chemical and Biochemical Engineering.

Engineering surfaces using photopolymerization to improve cochlear implant materials
Braden L. Leigh, 2018. University of Iowa.
Durable photografted zwitterionic hydrogel coatings to decrease biofouling and increase lubricity for biomaterials
Adreann Peel, 2023. University of Iowa.
Improving cochlear implant and tympanostomy tube surfaces via photografted zwitterionic thin films
Ryan R. Horne, 2023. University of Iowa.

Manuscripts in preparation

These are not published and are not cited as results anywhere on this site. The topics are listed so you know where the work is going.

Endotracheal tube insertion force and stenosis
A six-month sheep cohort with coated cochlear implant arrays
Coated PEEK for cranioplasty

Patents

US 11,525,069
Method of making a durable, cross-linked, covalently grafted anti-fouling coating. Issued December 13, 2022.
US 11,814,526
The coated-device system: a substrate with a covalently bonded, cross-linked zwitterionic hydrogel coating. Issued November 14, 2023.
US 12,116,498

Counterpart patents are granted in Australia (2017280359), China (ZL201780049849.X), Japan (7005535) and Mexico (388986). Applications are pending in Canada (3028732), Europe (EP 17740822.6) and South Africa (2018/08574). The patents are licensed exclusively from the University of Iowa Research Foundation.