Evaluation of EV Storage Buffer for Efficient Preservation of Engineered Extracellular Vesicles

Extracellular vesicles (EVs), detectable in all bodily fluids, mediate intercellular communication by transporting molecules between cells. The capacity of EVs to transport molecules between distant organs has drawn tremendous interest for clinical applications in diagnostics and therapeutics. Although EVs hold potential for nucleic acid-based and other molecular therapeutics, the lack of standardized technologies, including isolation, characterization, and storage, leaves many challenges for clinical applications, potentially resulting in misinterpretation of crucial findings. Previously, several groups demonstrated the problems of commonly used storage methods that distort EV integrity. This study reports a highly efficient EV storage condition, focusing on EVs’ capacity to protect their molecular cargo from biological, chemical, and mechanical damage. Compared with commonly used EV storage conditions, our EV storage buffer leads to less size and particle number variation at both 4°C and -80 °C, enhancing the ability to protect EVs while maintaining targeting functionality.