Milk exosomes in nutrition and drug delivery

Abstract

Exosomes are natural nanoparticles that originate in the endocytic system. Exosomes play an important role in cell-to-cell communication by transferring RNAs, lipids, and proteins from donor cells to recipient cells or by binding to receptors on the recipient cell surface. The concentration of exosomes and the diversity of cargos are high in milk. Exosomes and their cargos resist degradation in the gastrointestinal tract and during processing of milk in dairy plants. They are absorbed and accumulate in tissues following oral administrations, cross the blood-brain barrier, and dietary depletion and supplementation elicit phenotypes. These features have sparked the interest of the nutrition and pharmacology communities for exploring milk exosomes as novel bioactive food compounds and for delivering drugs to diseased tissues. This review discusses the current knowledgebase, uncertainties, and controversies in these lines of scholarly endeavor and health research.

Keywords: cargos; drug delivery; exosomes; milk; nutrition.

Figure 1.

Cell-to-cell communication by exosomes. A: biogenesis in donor cells. Note that the orientation of the plasma membrane (outer and inner leaflet) and membrane proteins remains unchanged in biogenesis. B: signaling in recipient cells. Endocytosis may occur by clathrin-dependent endocytosis, phagocytosis, lipid raft-mediated endocytosis, micropinocytosis, or caveolin-mediated endocytosis (20). ESCRT, endosomal sorting complex required for transport; MVB, multivesicular body (late endosome).