Sodium alginate piezoelectric hydrogel loaded with extracellular vesicles derived from bone marrow mesenchymal stem cells promotes repair of Achilles tendon rupture.

Accelerated repair of Achilles tendon rupture and prevention of re-rupture continue to pose significant technical challenges in orthopedic surgery and rehabilitation. Extracellular vesicles (EVs) derived from bone marrow mesenchymal stem cells exhibit substantial therapeutic potential for various degenerative diseases and tissue regeneration. However, the use of EVs alone for repairing ruptured Achilles tendons requires multiple invasive administrations, such as repeated injections, to maintain a therapeutic effect, which increases patient discomfort and the risk of infection. In this study, we innovatively combined EVs with sodium alginate-based piezoelectric hydrogel (SPH) to develop SPH-EVs. By leveraging the slow degradation of SPH in vivo, SPH-EVs enable sustained-release of EVs while generating electrical stimulation, ensuring that an effective therapeutic concentration is maintained at the Achilles tendon fracture site. Additionally, the integrated near-field communication (NFC) module within SPH-EVs allows for real-time monitoring of rehabilitation exercise intensity in the affected area, guiding patients to conduct rehabilitation training within a safe range and minimizing the risk of re-rupture.