Development of new self-powered cochlear implant: biocompatibility of PVDF nanofibers

The loss of hair cells within the human inner ear is an irreversible damage that causes sensorineural hearing loss (SNHL). The cochlear implant (CI) is currently the gold standard for treating this disease because it stimulates the cochlear nerve, bypassing the injured sensory cells and enabling the brain to receive the auditory stimuli. In order to enhance the quality of life for SNHL patients and reduce side effects associated with traditional CIs, ongoing research is focused on developing new self-powered cochlear stimulation devices based on piezoelectric nanomaterials. The aim of the thesis is to evaluate the in vitro biocompatibility of polyvinylidene fluoride (PVDF) nanofibers, which show promise as alternative materials for the production of cochlear implants. By imitating the cochlear sensory epithelium's function, these materials will stimulate the auditory neurons in response to sound wave vibration, with no energy resource needed. In this work the PVDF yarns fabricated with a new method, which includes fillers in the piezoelectric nanocomposites, were investigated for the future develop of acoustic sensor that could be incorporated in a total implantable cochlear implant. The analysis was assessed in vitro on different cell lines mimicking the inner ear tissues by testing the viability, the morphological changes and the neurite outgrowth. The results suggest the biocompatibility of the piezoelectric nanofibers, so that they could be the ideal candidates to improve the development of new implantable hearing devices without damaging the inner ear tissues.