 Our device is designed to deliver mesenchymal stem cell-derived extracellular vesicles, EVs, to the site of a spinal cord injury. This allows us to reduce scarring and promote healing by reducing inflammation and stimulating angiogenesis. Our device also delivers EVs over a period of time, allowing them to be more effective than single doses. In addition, this device can be used to deliver other types of therapeutic agents such as growth factors or drugs. This article was authored by A. O. Fang, Yifan Wang, Niu Guan, and others.