Stable Retinoid Analogue Targeted Dual pH-Sensitive Smart Lipid ECO/pDNA Nanoparticles for Specific Gene Delivery in the Retinal Pigment Epithelium

• Published in: ACS applied bio materials 2020-05, Vol.3 (5), p.3078-3086
• Main Authors: Sun, Da, Schur, Rebecca M, Sears, Avery E, Gao, Song-Qi, Sun, Wenyu, Naderi, Amirreza, Kern, Timothy, Palczewski, Krzysztof, Lu, Zheng-Rong
• Format: Article
• Language: English
• ISSN: 2576-6422; 2576-6422
• DOI: 10.1021/acsabm.0c00130

Dysfunctions caused by gene mutations in the retinal pigment epithelium (RPE) lead to retinal degeneration, visual function loss, and even blindness. RPE-specific gene replacement therapy holds great promise for treating monogenic ocular disorders in the RPE. Although the adeno-associated virus (AAV) has been approved for gene therapy to treat monogenic visual disorders, broad clinical applications of AAV-based gene therapy are limited by its gene loading capacity. In this work, we intended to design and develop a stable retinylamine analogue ACU4429-modified dual pH-sensitive ECO/pDNA nanoparticles for specific delivery of large therapeutic genes to the RPE. ACU4429 was first conjugated to a PEG 3.4 kD spacer with a pH-sensitive hydrazone linker at the distal end (ACU-PEG-HZ-MAL). The targeted dual pH-sensitive ECO/pDNA nanoparticles were then prepared by self-assembly of ACU-PEG-HZ-MAL, pH-sensitive lipid carrier ECO, and a plasmid DNA expressing the large ABCA4 gene. The formation of targeted ACU-PEG-HZ-ECO/pDNA nanoparticles was characterized by dynamic light scattering and gel electrophoresis. The incorporation of a hydrazone linker enhanced the cytosolic gene delivery, which translated to high ABCA4 expression in ARPE-19 cells for ACU-PEG-HZ-ECO/pABCA4 nanoparticles. The targeted nanoparticles also demonstrated excellent targeting efficiency in the interphotoreceptor matrix of Abca4 –/– mice, resulting in enhanced expression of the ABCA4 gene in the RPE. The ACU4429 PEG hydrazone-modified ECO/pDNA nanoparticles provide a promising nonviral platform to safely and effectively deliver therapeutic genes with unlimited sizes for the treatment of monogenic visual disorders.