Multimodal Programming of Extracellular Vesicles via Nano-Primed SECCS-Based 3D Microenvironments for Coordinated...

Chronic diabetic glucolipotoxicity is associated with progressive skeletal muscle atrophy, bone loss, cellular senescence, and ferroptotic injury. Because ferroptosis inhibition alone may not restore compromised myogenic capacity, we developed a combined stem cell-conditioning strategy integrating fullerol priming with the stem cell screen-enrich-combine(-biomaterials) circulating system (SECCS). This integrated three-dimensional culture platform uses porous β-TCP granules and intermittent medium circulation to generate BMSCs-derived extracellular vesicles (EVs). Among 2D-EVs, F-2D-EVs, SECCS-EVs, and F-SECCS-EVs, F-SECCS-EVs exhibited the strongest anti-ferroptotic and pro-regenerative effects. In glucolipotoxicity-challenged myoblasts, F-SECCS-EVs attenuated ferroptotic injury and enhanced proliferation and myogenic differentiation. Transcriptomic and functional experiments identified FOXO3 as an important mediator linking antioxidant defense with myogenic programs. In diabetic mice, F-SECCS-EVs improved motor function, muscle strength, myofiber cross-sectional area, and myogenic marker expression while modulating macrophage polarization. Free fullerol, 2D-EVs, and F-2D-EVs produced limited recovery, whereas SECCS-EVs were less effective than F-SECCS-EVs. These muscle benefits were accompanied by favorable changes in tibial bone structure. Collectively, these findings support fullerol-primed SECCS culture as a strategy for coordinating ferroptosis control with myogenic recovery in diabetes-associated musculoskeletal degeneration.