Nanoparticle-Based Retinal Prostheses: The Effect of Shape and Size on Neuronal Coupling

Abstract

The use of organic semiconductor nanoparticles (NPs) as retinal prostheses is attracting attention due to the possibility of injecting them directly into the desired tissue, with a minimally invasive surgical treatment. Polythiophene NPs localize in close proximity to the bipolar cell plasma membrane, which engulfs them, creating an intimate contact between the NP and the neuron. The intimate contact coupled with NP photoactivity are hypothesized to be the main guarantors of the electrostatic functioning of the bio-hybrid device. Since they may both be strongly affected by the geometric features of the NP, in this work, we use mathematical modeling to study the electrostatic polarization induced by light onto the NP and analyze how its spatial distribution is modified by varying the radius of the NP and its shape. Simulation results support the efficacy of the theoretical approach as a complementary virtual laboratory in the optimization of the current device and in the development of similar future NP-based technologies.