Research Advances in Drug Delivery System Based on Cell or Extracellular Vesicles

The drug delivery systems (DDSs) based on cells or extracellular vesicles (EVs)， taking natural particles as carriers， and covering EVs， the cell or purified cell membrane on the surface of drug， are emerging DDSs with great development potential in recent years. The cells and EVs are endogenous， with good biocompatibility， low immunogenicity and toxicity. Due to host characteristics， they also afford desirable targeting ability. In addition， using cells/extracellular vesicles as carriers to deliver chemical， genetic drugs could solve poor water solubility， high toxicity and other problems， and improve efficacy. In particular， Chinese medicine and its active ingredients had poor solubility and low bioavailability， the development of this delivery system could provide great potential for their application. This review presented an overview of the latest advances in DDSs based on cells or EVs from two aspects: their physiological functions and unique advantages as drug carrier.