INEAR3D: 3D printing at the service of hearing health
Led by the Charles Gerhardt Montpellier Institute (CNRS, UM, ENSCM), conducted in partnership with the Montpellier-based company Cilcare, and supported by the University Innovation Cluster (PUI), the Inear3D project is on track to recreate the architecture of the round window of the ear in 3D. An organoid in the making that could greatly facilitate the study of treatments for hearing health.
In Montpellier, theICGM's macromolecular materials team is on the verge of breaking a major barrier in hearing health. Commissioned by Cilcare, a company that develops and tests otological treatments, these researchers are working on the biomimetic printing of a complex organ: the round window of the ear, a biological barrier that ensures the diffusion of most active auditory ingredients. "The inaccessibility of the cochlea and the lack of human cell models are two obstacles," says Sylvie Pucheu, director of preclinical innovation at Cilcare.
Moving away from the animal model
Until now, it has been impossible to test treatments under development without using animal models. But Inear3D could soon offer biotechnology companies a unique and highly innovative alternative through 3D printing, thanks to its high resolution and reproducibility. For Sébastien Blanquer, a researcher at ICGM and the project's scientific leader, the approach meets both practical and ethical needs. "Working with animal models is very expensive and there are obvious ethical limitations, hence the need to develop biotechnologies," he says.
Since 2024, the scientist has been working closely with Cilcare, alongside two colleagues from the laboratory, Emmanuel Belamie, a specialist in materials science and bioengineering, and Marie-Noëlle Labour, an expert in cell biology. "Our department's approach is to work as a team and draw on each person's expertise to carry out research projects in the best possible way, " he explains. Together, they are working on the thin biological barrier that separates the middle ear from the inner ear. The team was then strengthened in April with the arrival of Gabin-Junior Endjeu Tchouassi, who has begun a doctoral project on this topic.
Bioprinted device
From a practical standpoint, scientists opted for stereolithography, a technique in its own right in the world of 3D printing, and one in which ICGM researchers are already recognized experts. The principle involves building the membrane layer by layer, with each layer being "photo-crosslinked," i.e., solidified by exposure to light. "But using this process, it is important to study various types of polymer materials and how they combine with cells to create a bio-printed device," explains Sébastien Blanquer.
“Ultimately, this device will enable rapid production of these membranes, with thicknesses ranging from 100 to 200 micrometers. Our goal is obviously to reproduce properties that are as close as possible to those of the round window, but also to be able to test the various active ingredients using a simpler protocol.” At the same time, the team has also approached Yvan Duhamel, an engineer at the Pro3D platform of the Laboratory of Mechanics and Civil Engineering (LGMC) at the University of Montpellier, to develop devices to facilitate the study of the diffusion of these substances.
Prototype in 2028
Developed as part of a CIFRE thesis, Inear3D was selected as a winner of the Companies and Campus call for projects in October 2024. Thanks to this initiative, which was launched by the Montpellier University Innovation Cluster, the team received €50,000 in funding to help cover the various costs associated with the project's research. "We have a collaboration agreement with Cilcare, but any additional support is welcome, " admits the researcher. "Research has a cost, and especially in cell culture, with biological consumables, the bill can be steep."
This fine example of partnership between the worlds of research and private enterprise should result in a prototype by 2028, before scientists hand over the fruits of their research to Cilcare, with the ambition of advancing the field of auditory therapy. According tothe Pasteur Institute, hearing loss is the most common sensory disorder in humans. Given what is at stake, this should make quite a splash...