Released from almost all cell types, found in blood and other bodily fluids, and thought to play a role in cell-to-cell communication, the tiny vesicles called exosomes are garnering a great deal of research interest both as potential diagnostic tools and as vehicles for drug delivery. Many researchers are developing methods for capturing, modifying, and tissue-targeting exosomes. One such tool—the protein CP05—may accomplish all three.
Haifang Yin of Tianjin Medical University in China and colleagues discovered CP05 in a search for proteins that bind CD63—a transmembrane protein abundant on the surface of exosomes. They’ve used this interaction to not only isolate exosomes from human serum via CP05-coated magnetic beads, but also to load cargo onto exosomes and send them to various tissues in mice.
To accomplish the latter, the team created peptide chimeras of CP05 with the tissue-targeting peptides M12, RVG, or SP94 to direct exosomes to muscle, brain, or ...