Mesenchymal Stem Cells‐Derived Extracellular Vesicles Mimetics as Osteoinductive Mediators for Bone Healing

Abstract Bone defects remain challenging to treat, with common therapies still relying on invasive approaches. Mesenchymal stem cell‐derived extracellular vesicles (MSC‐EVs) offer a promising alternative due to their regenerative and immunomodulatory properties, but challenges in scalable EV production limit clinical translation. Nanoghosts (NGs) are an emerging class of EV‐mimetics synthesized through the physical distortion of ghost cells that offer innate bioactivity similar to EVs while having more scalable yields. In this study, the osteogenic potential of NGs made from MSC ghosts (MSC‐NGs) is explored for the first time and contrasted with conventional MSC‐EVs. MSC‐NGs are generated through sonication, yielding two‐fold more vesicles compared to MSC‐EVs from the same number of cells. Unlike MSC‐EVs, MSC‐NGs significantly enhanced the osteogenic differentiation of MSCs, evidenced by increased alkaline phosphatase (ALP) activity and early mineralization. Proteomic analysis further revealed that MSC‐NGs are more enriched in osteogenesis‐related proteins than MSC‐EVs. In vivo, treatment of a 0.5 mm mouse femoral osteotomy with MSC‐NGs accelerated fracture healing, showing increased callus mineralization by day 14 and improved bone marrow reconstitution by day 21, along with reduced osteoclastic activity. These findings demonstrate MSC‐NGs as scalable and effective therapeutics for bone tissue engineering, offering advantages over MSC‐EVs in future bone healing strategies.