Development and chemical properties of retinal prostheses using photoelectric dyes coupled to polyethylene films with various anions to achieve high durability

Autor: Toshihiko Matsuo, Tenu Tanaka, Tetsuya Uchida, Koichiro Yamashita
Rok vydání: 2021
Předmět:
Zdroj: Polymer Journal. 53:719-729
ISSN: 1349-0540
0032-3896
DOI: 10.1038/s41428-021-00468-0
Popis: Photoelectric dyes, which absorb light and generate electric potential, have been shown to stimulate retinal neurons. Therefore, in the present work, a photoelectric dye was used to develop a retinal prosthesis to restore vision loss due to diseases, such as retinitis pigmentosa. The retinal prosthesis, referred to as a dye-coupled film, was prepared by chemically coupling the dyes to a polyethylene film surface. However, the amount of coupled dye decreased during an implantation test in a monkey’s eye. The dye consisted of a cation with photoresponsivity and Br−. Because thermal stability can be improved by anion exchange, we expected anion exchange to lead to stabilization of the chemical structure, resulting in improvement of the long-term durability of a retinal prosthesis. Therefore, the effects of exchanging Br− anions for PF6−, BF4−, and bis(trifluoromethanesulfonyl)imide (TFSI−) anions on the durability were investigated. The long-term durability of the dye-coupled films was found to be strongly related to the thermal stability of the photoelectric dye. The long-term durability of the dye-coupled film–PF6− and dye-coupled film–TFSI− improved by 637 and 215%, respectively, compared with that of the dye-coupled film–Br−. Our retinal prosthesis, referred to as a dye-coupled film, was developed by chemically coupling photoelectric dyes to the surface of a polyethylene film for restoring retinitis pigmentosa. However, the amount of coupled dye decreased during an implantation test in a monkey’s eye. For improving long-term durability, anion exchange from Br− to PF6−, BF4−, and bis(trifluoromethanesulfonyl)imide (TFSI−) was conducted. The long-term durabilities of the dye-coupled film–PF6−, –TFSI−, and –BF4− improved by 637, 215, and 48%, respectively, indicating that the dye-coupled film–PF6− exhibits the best long-term durability.
Databáze: OpenAIRE
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