Engineering extracellular vesicles derived from endothelial cells sheared by laminar flow for anti-atherosclerotic therapy through reprogramming macrophage.

Extracellular vesicles (EVs) secreted by endothelial cells in response to blood laminar flow play a crucial role in maintaining vascular homeostasis. However, the potential of these EVs to modulate the immune microenvironment within plaques for treating atherosclerosis remains unclear. Here, we present compelling evidence that EVs secreted by endothelial cells sheared by atheroprotective laminar shear stress (LSS-EVs) exhibit excellent immunoregulatory effects against atherosclerosis. LSS-EVs demonstrated a robust capacity to induce the conversion of M1-type macrophages into M2-type macrophages. Mechanistic investigations confirmed that LSS-EVs were enriched in miR-34c-5p and reprogrammed macrophages by targeting the TGF-β-Smad3 signaling pathway. Moreover, we employed click chemistry to modify hyaluronic acid (HA) on the surface of LSS-EVs, enabling specific binding to the CD44 receptor expressed by inflammatory macrophages within plaques. These HA-modified LSS-EVs (HA@LSS-EVs) exhibited exceptional abilities for targeting atherosclerosis and demonstrated promising therapeutic effects both in vitro and in vivo.