Lithium niobate nanoparticles may enable self-powered cochlear implants

Since their invention, cochlear implants have been improving the quality of hearing for individuals with sensorineural hearing loss; however, several drawbacks still exist. Next generation cochlear implants aim to exploit a different principle of function using piezoelectric materials. Danti et al. tested lithium niobate nanoparticles as an interface material for these inner ear devices.

Lithium niobate nanoparticles are a piezoelectric ceramic material considered promising for biomedical implants due to their advantages of being safe for implantation, non-ferromagnetic, and for cochlear implants, efficient in converting vibrations to electric signals.

The authors identified lithium niobate nanoparticles as a non-toxic material for use in cochlear implants to help promote robust immunomodulation and antimicrobial activity against harmful bacteria.

“It is important to optimize the material contact with the neurons and avoid additional loss of voltage due to fibrotic tissue. Therefore, immunomodulatory materials are very useful to this purpose,” said author Serena Danti.

By incorporating the lithium niobate nanoparticles into a piezoelectric polymer (polyvinylidene fluoride trifluoroethylene) in the form of submicrometric fibers, the authors were able to further enhance the overall piezoelectric response.

“The development of a high-performance piezoelectric biomaterial, to be used as a cochlear transducer, would improve the quality of life of deaf people since it would offer a cost-effective, simple, biomimetic, water and magneto-compatible treatment option,” said Danti.

Moving forward, the authors hope to test these nanoparticles, possibly in combination with a polymer, on an electrode surface and optimize the coating procedure. After that, the device may be tested ex vivo, and then perhaps later in animal trials using a miniaturized electrode, to assess possible local inflammatory response and biocompatibility.

Source: “Lithium niobate nanoparticles as biofunctional interface material for inner ear devices,” by Serena Danti, Bahareh Azimi, Mariarita Candito, Alessandra Fusco, Mohammad Sajad Sorayani Bafqi, Claudio Ricci, Mario Milazzo, Caterina Cristallini, Masud Latifi, Giovanna Donnarumma, Luca Bruschini, Andrea Lazzeri, Laura Astolfi, and Stefano Berrettini, Biointerphases (2020). The article can be accessed at https://doi.org/10.1116/6.0000067 .