Abstract
Plant-based extracellular vesicles (PBEVs) have been recognized for their wide range of applications in drug delivery however, the extent of their medicinal applicability depends on how well they are preserved and stored. Assessing their physicochemical properties, such as size, particle concentration, shape, and the activity of their cargo, forms the foundation for determining their stability during storage. Moreover, the evaluation of PBEVs is essential to ensure both safety and efficacy, which are critical for advancing their clinical development. Maintaining the biological activity of EVs during storage is a challenging task, similar to the preservation of cells and other cell-derived products like proteins. However, despite limited studies, it is expected that storing drug-loaded EVs may present fewer challenges compared to cell-based therapies, although some limitations are inevitable. This article provides a comprehensive overview of current knowledge on PBEVs preservation and storage methods, particularly focusing on their role as drug carriers. PBEVs hold promise as potential candidates for oral drug administration due to their effective intestinal absorption and ability to withstand both basic and acidic environments. However, maintaining their preservation and stability during storage is critical. Moreover, this review centers on the isolation, characterization, and storage of PBEVs, exploring the potential advantages they offer. Furthermore, it highlights key areas that require further research to overcome existing challenges and enhance the development of effective preservation and storage methods for therapeutic EVs.