Extracellular vesicles as a drug delivery system:A systematic review of preclinical studies.

Abstract During the past decades, EVs have emerged as attractive drug delivery systems. Here, we assess their pre-clinical applications, in the form of a systematic review. For each study published during the past decade, disease models, animal species, EV donor cell types, active pharmaceutical ingredients (APIs), EV surface modifications, API loading methods, EV size and charge, estimation of EV purity, presence of biodistribution studies and administration routes were qualitatively analyzed in a defined and reproducible way. We have interpreted the trends we observe over the past decade, to define the niches where to apply EVs for drug delivery in the future and to provide a basis for regulatory guidelines.