Characterization of a Polymer‐based, fully organic prosthesis for implantation into the subretinal space of the rat Antognazza, Maria Rosa Di Paolo, Mattia Ghezzi, Diego Mete, Maurizio Di Marco, Stefano Maya‐Vetencourt, José Fernando Maccarone, Rita Desii, Andrea Di Fonzo, Fabio Bramini, Mattia Russo, Angela Laudato, Lucia Donelli, Ilaria Cilli, Michele Freddi, Giuliano Pertile, Grazia Lanzani, Gugliemlo Bisti, Silvia Benfenati, Fabio Prosthesis Retina Rats The work was supported by Telethon – Italy (Grants GGP12033 to GL, FB, and SB, and GGP14022 to GP and FB); EU project FP7-PEOPLE-212-ITN 316832 “OLIMPIA” (to FB and GL); Fondazione Cariplo (project ON-IRIS 2013–0738 to MRA, GF, and DG); Compagnia di San Paolo (project ID 4191 to DG and FB), the Italian Ministry of Health (project RF-2013-02358313 to GP, GL, and FB), and Istituto Italiano di Tecnologia (prestartup project to GL and FB). Replacement strategies arise as promising approaches in case of inherited retinal dystrophies leading to blindness. A fully organic retinal prosthesis made of conjugated polymers layered onto a silk fibroin substrate is engineered. First, the biophysical and surface properties are characterized; then, the long-term biocompatibility is assessed after implantation of the organic device in the subretinal space of 3-months-old rats for a period of five months. The results indicate a good stability of the subretinal implants over time, with preservation of the physical properties of the polymeric layer and a tight contact with the outer retina. Immunoinflammatory markers detect only a modest tissue reaction to the surgical insult and the foreign body that peaks shortly after surgery and progressively decreases with time to normal levels at five months after implantation. Importantly, the integrity of the polymeric layer in direct contact with the retinal tissue is preserved after five months of implantation. The recovery of the foreign-body tissue reaction is also associated with a normal b-wave in the electroretinographic response. The results demonstrate that the device implanted in nondystrophic eyes is well tolerated, highly biocompatible, and suitable as retinal prosthesis in case of photoreceptor degeneration. 2026-02-17T11:27:13Z 2026-02-17T11:27:13Z 2016-05-30 journal article Antognazza, Maria Rosa et al. Characterization of a Polymer‐based, fully organic prosthesis for implantation into the subretinal space of the rat. 2016, Advanced healthcare materials 5 (17), 2271-2282. https://doi.org/10.1002/adhm.201600318 https://hdl.handle.net/10481/111091 10.1002/adhm.201600318 eng info:eu-repo/grantAgreement/EC/FP7/316832 http://creativecommons.org/licenses/by-nc-nd/4.0/ open access Attribution-NonCommercial-NoDerivatives 4.0 Internacional Wiley