Conclusion
TGF-β signalling differentially regulated by fluid shear stress produced in our system and exogenous TGF-β3 addition was confirmed to play an important role in the enhanced production of EVs with modified protein cargoes. We suggest that the T-a3D system leads to the efficient production of MSC-EVs with high potential in therapies and clinical development.
Methods
Our system enabled preparation of a highly concentrated EV-containing medium for efficient EV isolation and purification with higher yield and efficacy.
Results
MSC spheroids in T-a3D system (T-a3D spheroids) showed high expression of CD9 and TGF-β3, which was dependent on TGF-β signaling. Treatment with EVs produced under T-a3D conditions (T-a3D-EVs) led to significantly improved migration of dermal fibroblasts and wound closure in an excisional wound model. The relative total efficacy (relative yield of single-batch EVs (10-11-fold) × relative regeneration effect of EVs (2-3-fold)) of T-a3D-EVs was approximately up to 33-fold higher than that of 2D-EVs. Importantly the quantitative proteomic analyses of the T-a3D spheroids and T-a3D-EVs supported the improved EV production as well as the therapeutic potency of T-a3D-EVs.