Basic Points of Exosomes and Application for Intracellular Delivery of Therapeutic Molecules

Abstract

Exosomes (extracellular vesicles), which are secreted from almost all human cells, have been shown to participate in cell-to-cell communication. “Message” molecules including microRNAs and enzymes are capsulated in the exosomes, and secreted exosomes play crucial roles in human homeostasis and disease progression including cancer. In addition, exosomes have been highly expected as next-generation carriers for intracellular delivery of therapeutic molecules because of their pharmaceutical advantages such as (i) low cytotoxicity, (ii) controlled immunogenicity, (iii) effective usage of cell-to-cell communication routes, (iv) targeting brain owing to blood-brain barrier permeability, (v) controlled expression of artificial proteins in exosomal membranes. In this review, basic points of exosomes including vesicular characteristics, generation and secretion pathways, cellular uptake mechanisms, and application for intracellular delivery of therapeutic molecules with artificial cellular targeting systems are introduced.