Engineering Extracellular Vesicles Derived from 3D Cultivation of BMSCs Enriched with HGF Ameliorate Sepsis-Induced Lung Epithelial Barrier Damage.

Sepsis is a critical condition with high mortality, often leading to acute lung injury (ALI) due to uncontrolled inflammatory responses and alveolar epithelial damage. Extracellular vesicles (EVs), particularly mesenchymal stem cell-derived EVs, have shown therapeutic potential in sepsis-related organ dysfunction by transferring RNAs and proteins. However, their clinical use is limited by low efficacy and yield. To address this, 3D-cultured MSCs (3D-MSCs) are generated using MicroTissues 3D Petri Dish. These 3D-MSCs demonstrate improved protection and proliferation of MLE-12 cells in vitro. Mechanistic studies are conducted to explore the enhanced protective effects of 3D-MSCs derived EVs (3D-EVs) in a septic-ALI model. Proteomic and molecular analyses of 3D-EVs revealed that they are enriched in hepatocyte growth factor (HGF). HGF helps maintain the barrier function of damaged alveolar epithelium through the PI3K-AKT signaling pathway. Overall, 3D-EVs effectively ameliorate sepsis-induced ALI and enhance prognosis by enriching and delivering HGF, suggesting that their application represents a promising treatment strategy for septic ALI.