The transplantation of mesenchymal stem cells-derived secretome, particularly extracellular vesicles is a promising therapy to suppress spinal cord injury-triggered neuroinflammation. However, efficient delivery of extracellular vesicles to the injured spinal cord, with minimal damage, remains a challenge. Here we present a device for the delivery of extracellular vesicles to treat spinal cord injury. We show that the device incorporating mesenchymal stem cells and porous microneedles enables the delivery of extracellular vesicles. We demonstrate that topical application to the spinal cord lesion beneath the spinal dura, does not damage the lesion. We evaluate the efficacy of our device in a contusive spinal cord injury model and find that it reduces the cavity and scar tissue formation, promotes angiogenesis, and improves survival of nearby tissues and axons. Importantly, the sustained delivery of extracellular vesicles for at least 7 days results in significant functional recovery. Thus, our device provides an efficient and sustained extracellular vesicles delivery platform for spinal cord injury treatment.

间充质干细胞衍生的分泌体（尤其是细胞外囊泡）的移植是抑制脊髓损伤引发的神经炎症的一种有前景的疗法。然而，以最小的损伤将细胞外囊泡有效递送至受伤的脊髓仍然是一个挑战。在这里，我们提出了一种用于输送细胞外囊泡以治疗脊髓损伤的装置。我们证明，结合间充质干细胞和多孔微针的装置能够输送细胞外囊泡。我们证明，局部应用于硬脊膜下方的脊髓病变不会损伤病变。我们评估了我们的装置在脊髓挫伤模型中的功效，发现它减少了空腔和疤痕组织的形成，促进血管生成，并提高了附近组织和轴突的存活率。重要的是，持续输送细胞外囊泡至少 7 天可带来显着的功能恢复。因此，我们的装置为脊髓损伤治疗提供了有效且持续的细胞外囊泡递送平台。