Dynamic Mechanical Loading Modulates Extracellular Vesicle Production and Cargo in Meniscus Fibrochondrocytes

ABSTRACT The meniscus is a fibrocartilaginous tissue critical for knee stability and load distribution, but its poor healing capacity makes regeneration after injury a major clinical challenge. Extracellular vesicles (EVs) are emerging as promising cell‐free therapeutics for tissue regeneration. However, their clinical translation remains limited by low yield and variable bioactivity. This study investigates how dynamic mechanical loading regulates the production, composition, and function of meniscus fibrochondrocyte‐derived EVs (MFC‐EVs). Using a custom bioreactor system, cells are subjected to physiologically relevant cyclic tensile loading. Mechanical stimulation significantly increases EV production, likely through the ESCRT‐independent pathway, without altering vesicle size or tetraspanin expression. “Mechanically primed” EVs enhance aggrecan expression in recipient mesenchymal stromal cells (MSCs), mirroring the loading‐response phenotype of their source cells. Proteomic profiling identifies 380 unique proteins across all EV groups, with primed EVs enriched in extracellular matrix‐ and cytoskeleton‐associated proteins, along with pathways related to tissue morphogenesis, cell migration, and cartilage development. Together, these findings show that physiologic mechanical loading enhances MFC‐EV yield and is associated with distinct EV cargo profiles and recipient MSC gene expression responses. This work provides a scalable, biologically inspired strategy for engineering EV‐based approaches with potential applications in meniscus repair and musculoskeletal regeneration.