Vision restoration in photoreceptor-degenerated mice and macaque monkeys using nanowires

Abstract Photoreceptor degeneration diseases, such as retinitis pigmentosa and age-related macular degeneration, are major causes of blindness. Here we evaluate the performance of Au nanoparticle-coated titania (TiO2-x) nanowire (NW) arrays as artificial photoreceptors to restore image-forming vision in blind mice and non-human primates with photoreceptor degeneration. We first demonstrated that blind mice with the subretinal implant of NW arrays were capable of detecting static, moving and flashing objects, with a visual acuity of 0.3 cpd, measured up to 9 months after the implant surgery. Using chronic in vivo calcium imaging, we continuously monitored light-induced responses of neurons in the primary visual cortex (V1) in NW-implanted blind mice for over 14 weeks. Light responses of V1 neurons first appeared at 2 days after the surgery and the number of light-responsive V1 neurons peaked 1 week after the implant surgery, and the latency of these responses decreased over time. These results collectively suggested the plasticity and improvement in the encoding of visual information in V1 after NW implant surgery. We then implanted NW arrays subretinally in macaque monkeys, showing that the NW arrays did not cause adverse responses 8 weeks post surgery. Finally, visually-guided saccades were restored in macaque monkeys with the subretinal implant of NW arrays. Our findings demonstrated the possibility to utilize nanomaterials as artificial photoreceptors to ameliorate visual deficits of patients with photoreceptor degeneration.