Phosphatidylserine (PS) is a biocompatible phospholipid with a negative charge at biological pH, and is a component of cell membranes. It is mainly found in animal viscera and plants. PS is a key factor in recruiting and activating many enzymes and structural components, marking important events such as the clearance of apoptotic cells and the internalization of viruses by host cells. When cells undergo apoptosis, large amounts of PS are transferred to the outer membrane. Exposed PS serves as a specific recognition signal for macrophages to phagocytose apoptotic cells. Therefore, nanomaterials containing PS can deliver drugs to specific sites rich in macrophages. https://www.cd-bioparticle...