Magnetic‐Guided Delivery of Antisense Oligonucleotides for Targeted Transduction in Multiple Retinal Explant and Organoid Models

Antisense oligonucleotide (ASO) therapy holds promise in gene therapy but faces challenges due to poor delivery efficiency and limited evaluation models. This investigation employs magnetic nanoparticles (MNPs) to augment the delivery efficiency of ASOs. It assesses their distribution and therapeutic efficacy across various models, including retinal explants from mice and macaques or human retinal and inner ear organoids. Retinal explants from both mice and monkeys are methodically arranged to expose the ganglion cell layer (GCL) or the photoreceptor layer (PL). MNPs markedly enhanced the penetration and targeting of ASOs, resulting in a 60% accumulation in the GCL or 72% in the photoreceptors. Furthermore, an in vitro biomimetic model of the neuroretina-RPE/choroid-sclera complex is developed to examine ASO distribution under dynamic flow conditions. Moreover, the utilization of MNP-assisted ASO-Cy3 markedly enhanced transfection efficiency within human retinal and inner ear organoids, resulting in an increase in positively transfected cells to 60% and 70%, respectively. Here, for the first time, an MNP-explant-organoid platform is carried out for the promotion of ASO transfection efficiency, therapeutic screening and targeted delivery. This development paves the way for investigating novel gene therapy strategies targeting retinal diseases.