Targeted Delivery of Engineered Exosomes and the Advances for Their Applications in Ocular Tissue

Exosomes, a type of nanoscale vesicle produced by cells, are highly biocompatible and immunogenic. They play a crucial role in cell-to-cell communication, which contain proteins, ribonucleic acid, and other materials that can be transported to the receipt cells. Exosomes possess significant potentials as diagnostic indicators for disorders and as delivery systems for tailored therapeutics. They also exhibit distinct distributions in the eye, contributing to the regulation of both physiological and pathological processes, and are intricately linked to the onset and progression of ocular diseases. Based on the distinctive anatomical characteristics of the eye, utilization of exosomes to deliver drugs in treating the ocular diseases has shown promising prospects. However, owing to the inadequate delivery efficacy of unmodified exosomes, they need to be tailored to be more effective. In this review, we provide a brief overview of the exosome distribution in the eye and their functions in the onset and progression of the ocular diseases as well as exosome-based therapies. A large portion of this review describes the methods of exosome cargo loading, targeted modifications and their applications in treating ocular diseases. The advancements of this field are anticipated to yield a considerable therapeutic impacts, markedly enhancing the probability of visual restoration.