sEV from 3D‐Cultured MSCs Engineered with miR‐27b‐3p for Treating TMJ‐OA by Suppressing Osteoclastogenesis

Temporomandibular joint osteoarthritis (TMJ-OA), a refractory osteoarticular disorder, is critically hindered by inflammation-mediated bone metabolic imbalance during disease progression. Building on the previous discovery that inflammation-indued mesenchymal stem cell-derived small extracellular vesicles (sEV) regulate macrophage polarization via the miR-27b-3p/CSF-1 axis, functionally enhanced engineered sEV (sEV-r) is developed through 3D dynamic culture coupled with electroporation technology. This strategy leverages 3D culture to optimize vesicle bioactivity and employs electroporation for high-efficiency miR-27b-3p loading, endowing sEV-r with both inherent targeting capacity and amplified anti-inflammatory functionality. Experimental validation demonstrate that sEV-r effectively suppresses CSF-1-driven inflammatory cascades via efficient miR-27b-3p delivery while enhancing the chemotactic migration of bone marrow mesenchymal stem cells (BMSCs). In vivo studies demonstrate that sEV-r exhibits superior therapeutic efficacy in both acute inflammatory (mouse ear edema) and chronic osteoarthritic (TMJ-OA) models. In TMJ-OA models, sEV-r exert dual therapeutic mechanisms: modulating macrophage phenotype polarization to optimize the inflammatory microenvironment, and inhibiting oxidative stress to block abnormal osteoclast activation. These effects collectively improve subchondral bone microstructure and restore bone metabolic equilibrium. This study establishes a novel engineering strategy for sEV-based targeted therapy, providing critical insights into precision interventions for TMJ-OA.