Nanoparticle-based optical interfaces for retinal neuromodulation: a review

• Published in: Frontiers in cellular neuroscience Vol. 18; p. 1360870
• Main Authors: Stoddart, Paul R, Begeng, James M, Tong, Wei, Ibbotson, Michael R, Kameneva, Tatiana
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Research Foundation 20-03-2024; Frontiers Media S.A
• Subjects: Acuity; Bipolar cells; Cell differentiation; Cellular Neuroscience; Electrical stimuli; Electrodes; Eye; Interfaces; Macular degeneration; Magnetic fields; Manufacturers; nanoparticle transducers; Nanoparticles; Neuromodulation; optical nanosensors; Optics; Pharmacokinetics; Photoreceptors; Prostheses; Prosthetics; Retina; Retinal degeneration; Retinal ganglion cells; retinal pharmacokinetics; retinal prosthesis; Transplants & implants; neuromodulation; retinal prosthesis; retinal pharmacokinetics; retinal degeneration; nanoparticle transducers; optical nanosensors
• ISSN: 1662-5102; 1662-5102
• DOI: 10.3389/fncel.2024.1360870

Degeneration of photoreceptors in the retina is a leading cause of blindness, but commonly leaves the retinal ganglion cells (RGCs) and/or bipolar cells extant. Consequently, these cells are an attractive target for the invasive electrical implants colloquially known as "bionic eyes." However, after more than two decades of concerted effort, interfaces based on conventional electrical stimulation approaches have delivered limited efficacy, primarily due to the current spread in retinal tissue, which precludes high-acuity vision. The ideal prosthetic solution would be less invasive, provide single-cell resolution and an ability to differentiate between different cell types. Nanoparticle-mediated approaches can address some of these requirements, with particular attention being directed at light-sensitive nanoparticles that can be accessed via the intrinsic optics of the eye. Here we survey the available known nanoparticle-based optical transduction mechanisms that can be exploited for neuromodulation. We review the rapid progress in the field, together with outstanding challenges that must be addressed to translate these techniques to clinical practice. In particular, successful translation will likely require efficient delivery of nanoparticles to stable and precisely defined locations in the retinal tissues. Therefore, we also emphasize the current literature relating to the pharmacokinetics of nanoparticles in the eye. While considerable challenges remain to be overcome, progress to date shows great potential for nanoparticle-based interfaces to revolutionize the field of visual prostheses.