Targeted Nano-enhanced Optical Delivery of opsin for dry-AMD therapy

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Geographic atrophies (GA) in dry-age related macular degeneration (AMD) is characterized by degeneration of photoreceptors, and is the leading cause of new vision loss in ~15 million persons. There is neither a cure that can stop the degeneration nor a therapy to restore vision loss. We have developed ambient-light activatable multi-characteristic opsin (MCO-II) to allow stimulation of retinal ganglion cells (RGCs) for vision rehabilitation. However, clinical translation of such gene therapy to patients with GA will require targeted delivery of opsin- encoding genes into the atrophic regions without perturbing remaining functional retina. Therefore, we have developed a near-infrared laser based efficient method for in-vivo targeted gene delivery into retina. In this Nano-enhanced Optical Delivery (NOD) method, we utilize surface plasmon resonance based field enhancement by functionalized gold nanorods (fGNRs) to transiently perforate cell membrane to deliver the molecules. In the Phase I, we demonstrated targeted in-vivo optical delivery of MCO-II to degenerated retina in mice using NOD at multiple wavelengths. Further, we made comparative study of continuous wave (cw) and nanosecond pulsed laser based NOD of MCO-II plasmids and determined optimized laser parameters for efficient transfection of retina. No detectable ocular damage was observed due to NOD. Further, the immunostaining of retina after in-vivo NOD of MCO-II plasmids showed no noticeable cell death. Electrophysiology studies demonstrate that MCO-II sensitized cells are activatable by light, allowing visually evoked cortical activities. The overall goal of this Phase-II proposal is to develop the combination NOD product for photosensitizing RGCs in the degenerated retina in a safe manner and stimulating photosensitized RGCs by ambient light for vision rehabilitation. Towards this goal we have following aims: (1) Quantify long-term stability and safety of NOD in mice model lacking photoreceptors; (2) Evaluate functioning of targeted retinal regions after re-photosensitization of RGCs using NOD assisted MCO-II delivery in mice and rat models; and (3) GLP study of toxicity, biodistribution and efficacy of NOD-delivered MCO-II plasmids in non-human primates (NHPs). This collaborative proposal brings together complementary expertise in optical delivery, optogenetics, ophthalmology, instrument, molecular biology, nanomaterials, retina biology and function, neuroscience/behavior, electrophysiology, biostatistics, and toxicology to address the challenge in retinal degeneration. The safety/efficacy study in NHPs will be performed at CRO facility. Upon completion of the Phase II we envision to advance: (i) NOD product development for clinical studies, (ii) IND application to FDA, and (iii) partnering with venture capital and Pharma company for commercialization. Success of this proposal will lead to a new clinical approach for treating patients with GA by conventional intravitreal injection of fGNRs and MCO-II. The NOD based targeted delivery of impermeable exogenous materials (small molecules, proteins and genes) will benefit drug, vaccine and gene therapy.