Autosomal dominant optic atrophy (ADOA) is a rare progressive disease mainly caused by mutations in OPA1, a nuclear gene encoding for a mitochondrial protein that plays an essential role in mitochondrial dynamics, cell survival, oxidative phosphorylation, and mtDNA maintenance. ADOA is characterized by the degeneration of retinal ganglion cells (RGCs). This causes visual loss, which can lead to legal blindness in many cases. Nowadays, there is no effective treatment for ADOA. In this article, we have established an isogenic human RGC model for ADOA using iPSC technology and the genome editing tool CRISPR/Cas9 from a previously generated iPSC line of an ADOA plus patient harboring the pathogenic variant NM_015560.3: c.1861C>T (p.Gln621Ter) in heterozygosis in OPA1. To this end, a protocol based on supplementing the iPSC culture media with several small molecules and defined factors trying to mimic embryonic development has been employed. Subsequently, the created model was validated, confirming the presence of a defect of intergenomic communication, impaired mitochondrial respiration, and an increase in apoptosis and ROS generation. Finally, we propose the analysis of OPA1 expression by qPCR as an easy read-out method to carry out future drug screening studies using the created RGC model. In summary, this model provides a useful platform for further investigation of the underlying pathophysiological mechanisms of ADOA plus and for testing compounds with potential pharmacological action.

Exosomes are biological nanoparticles (30–150 nm) secreted by most eukaryotic cells. They are composed of a lipid bilayer membrane and an inner compartment that stores various cellular components. In recent years, research on exosomes has grown exponentially due to their biocompatibility, low immunogenicity and cytotoxicity, and their permeability to biological barriers. Among the most promising applications of exosomes are their diagnostic and therapeutic potential, the latter being especially relevant due to their ability to act as a vehicle for drugs. Before exosomes can be applied clinically, it is necessary to optimize the isolation of these nanoparticles from various sources, as well as to carry out their physical and biochemical characterization. Furthermore, their ability to encapsulate molecules with therapeutic effects within them must be perfected. To this end, analytical methods are a key tool for developing each of these steps, and it is essential to understand their principles, strengths, and challenges. In addition, it is necessary to overcome limitations such as the availability of safe sources, the scalability of production, the standardization of isolation, purification, and encapsulation, the inherent heterogeneity of exosomes themselves, the prolongation of in vivo lifespan, and the long-term preservation of these nanoparticles. An alternative is the synthesis of exosome-like nanoparticles, which is less complex but more prone to high production and tailored structure and composition. This review addresses the latest advances in drug delivery focused on exosomes and exosome biomimetic nanoparticles, comparing their advantages and drawbacks from a practical perspective.