Polynovo to test biopolymer 'glue' for new bionic ear

PolyNovo Biomaterials, a 50-per cent owned subsidiary of Perth's Xceed Biotechnology (ASX:XBL), has entered a research alliance with Melbourne's Bionic Ear Institute to develop a more sophisticated bionic ear that could dramatically improve patients' hearing by inducing new auditory nerves to grow and connect with the bionic implant.

PolyNovo has already developed a flexible, biodegradable polyurethane polmer that breaks down in the body after providing a biocompatible scaffold for cell colonization and growth.

PolyNovo CEO Dr Ian Griffiths said the Bionic Ear Institute had contacted his company after hearing about the biopolymer's potential use as a biocompatible 'glue' and substrate for repairing broken bones.

Griffiths said another advantage of the polymer is that it can be synthesised and cured at a temperature below 40OC, allowing biologically active molecules like nerve growth hormones and neurotrophic factors to be incorporated within its structure.

The polymer implant releases these active factors as it slowly degrades, so it would act both as a scaffold for colonisation by new nerve cells in the ear, as well as stimulating and guiding their growth.

PolyNovo chemists would work with Bionic Ear Institute to tailor the polymer's properties to the requirements of the new bionic ear.

Currently, the bionic ear is surgically implanted to bring an electrode array into contact with a relatively small subset of auditory nerves along the cochlear. The size of each electrode, and the limitations of the microsurgical technique, restricts the range of frequencies the patient can detect, and limits their response to discrete frequencies within the audible spectrum.

By stimulating larger numbers of nerve cells to grow into the implant and make intimate contact with an increased number of electrodes the patient would be able to detect a greater range of frequencies, at more closely spaced intervals, so they would hear sounds more 'naturally.'

The Director of the Bionic Ear Institute, Professor Graeme Clarke, said PolyNovo's novel polymer technology appeared to provide significant advantages over conventional biodegradable polymers.

Clark said he was confident the collaboration would provide the breakthroughs required to develop the next generation of nerve-repair devices.

Clark recently announced plans to develop bionic implants that would transmit nerve signals across spinal cord gaps in patients who have suffered paralysing injuries.

Griffiths said PolyNovo would focus on the bionic ear project over the next few years, using it as a model to test the broader potential of the company's unique polymers for nerve repair.