The research focuses on the investigation of semiconductive and conductive conjugated polymers used as interfaces to stimulate neurons with light and on their exploitation for generating organic neuroprostheses for the treatment of genetic retinal degenerative diseases, namely Retinitis pigmentosa (RP) and atrophic age-related macular degeneration (AMD), for which no effective treatment is currently available (Benfenati & Lanzani, 2018; Di Maria et al., 2018). Through multiple experimental approaches, including patch-clamp, multi-electrode arrays, in vivo electrophysiology and behavioral tests, we pursue the application of the aforementioned interfaces in experimental models of retinal pathologies, such as the Royal College of Surgeon (RCS) rats and pigs bearing photoreceptor degeneration induced by iodoacetic acid treatment.
We initially demonstrated that primary neurons can be successfully grown onto a photovoltaic organic polymer and electrically stimulated by light (Ghezzi et al., 2011), and subsequently that blind retinas in contact with the polymer recover light-sensitivity (Ghezzi et al., 2013; Feyen et al., 2016). More recently, we demonstrated that the retinal prosthesis implanted in the subretinal space of blind RCS rats promotes the in vivo rescue of normal visual functions by improving the pupillary light reflex and light-dependent behavior, recovering the cortical responses to light stimuli and visual acuity to levels comparable to normal animals (Maya-Vetencourt et al., 2017; Antognazza et al., 2016). In parallel, we are working with an artificial retina specially designed for the large eye of the biomedical pig. We are implanting such photovoltaic device in pigs bearing photoreceptor degeneration, to evaluate the rescue of visual functions in an eye that resembles that of humans and to develop the surgical technique of implantation in a larger eye as the last experimental step before the phase-1 experimentation in man. We are also currently testing new generation polymeric and photochromic interfaces based on new materials and geometries to develop more advanced, next-generation retinal prosthesis.